Buyers guide for a car magazine to be done by 10th March

[Ian S]

Hi Folks

We've been asked if we can write and supply a 'buyers guide'.

Here is work done so far and now we'd like input from you to improve it.

Facts and data that you know.

Corrections to errors that we've made.

We need to keep it neat and concise. I don't know if the magazine will publish the whole lot but they did ask for as much detail as possible.

I'd like to provide the best and most accurate guide anyone has done so far.

We've approached it from the view point of a new buyer who'd like to know the details before they buy.

Please add you suggestions either in a new post or edit the main posts and add in another colour such as red. Not Blue as they are my comments or questions.

They will then either be integrated in black into the final work or deleted as we feel is appropriate.

Thanks.

[Ian S]

RTOC RENAULT 5 GT TURBO BUYING GUIDE

This month the buying guide is on that cult Hot Hatch, the Renault 5 GT Turbo. Back in the late 80’s & early 90’s these cars were many young man’s dream and were slugging it out with Peugeot 205 & VW Golf GTI’s round every ring road & leisure park car park. There have been many buying guides for these cars over the years, giving differing recommendations on what’s right & wrong. However this time Performance French Cars have created this buying guide in conjunction with the Renault Turbo Owners Club (www.rtoc.org) to ensure that you are provided with the most accurate and comprehensive guide so far.

Over the last 25 years the Renault 5 GT Turbo has continued to appeal to many car enthusiasts from competing and winning in various racing series to road use engine and chassis tuning to styling modification from the sensible and practical to the ridiculously exaggerated with actual performance loss.

Many people remember the whole Ali-G big wheels & body kit scene which the RTOC believe tarnished the reputation of the 5 GT Turbo in the minds of many people. In more recent years though there has been a shift in restoring the cars back to factory fresh examples and Big Steve’s car pictured here was one of the first cars restored back in 2006.

HISTORY

The Renault 5 was launched in 1972 and spawned many performance versions from the Turbocharged Gordini, to the wide body Turbo in 1980 that won the 1981 Monte Carlo rally, the Turbo 2 in 1983 and the Maxi in 1985 of which only 20 were made. In total only 5007 T1, T2 and Maxi were made.

The second generation Supercinq (Super Five) was launched in 1985 and was styled by Marcello Gandini who had previously penned the Lamborghini Countach. The chassis was based on the Renault 9/11 models with McPherson strut front suspension and transverse engine and gearbox, but the Renault 5 styling trademarks were retained.

When the Supercinq was launched the GT Turbo was not offered for sale but was included in the brochure as the “Coupe” model. This Coupe model was described as being developed for racing only and not available for sale, but by 1986 the GT Turbo was launched with a price tag of £7,710. Producing 115bhp, it was fitted with a slightly different body kit to the one shown here.

In 1987 Renault made a number of small but significant changes and designated this the phase 2 model. Most obvious is the painted smoothed body kit that reduced the car's drag coefficient from 0.36 to 0.35, different wheels and seat cloth and a more comprehensive centre console. But under the bonnet were some reliability improvements to address some of the issues seen with the Phase 1 hot starting problems; an Anti Percolation Fan to cool the carburettor, and when the engine is off, to cool the turbo compressor and also intercooler when it’s thermostatically controlled diverter flap is open. Also a water cooled turbo charger and changed routing of the cooling system pipes. The power increased by 5 BHP to 120 BHP. In the ECU was moved from over the turbo, the heat from which slowly damaged it, to behind the bulkhead. In 1990/91 they re-routed the throttle cable to the carb and replaced the rubber steering column UJ with a metal UJ, provided cloth covered door cards, more sound proofing in the boot and a boot light. In late 1991 the 5 GT Turbo was discontinued make H reg the last available, though there are a few J and K reg's around these were ones kept in Dealerships and sold later.

There are approximately 3500 GT Turbo’s still registered with the DVLA and with the newest cars now 20 years old parts are becoming harder to source as Renault withdraw components from there dealership network. However due to the fanatical following and a number of specialists, there are few parts that are truly unobtainable.

Advice

Look at the cost of buying vs. the cost of making it / keeping it road worthy. Things which would almost write the car off: rotten floor, inner and outer sills, rotten windscreen surround as many panels are no longer available from Renault.
Brakes are fairly cheap and available but things like rear compensators are costly to replace.

Don't buy one unless you know what you are looking for or know someone who does as 90% of the time the car will need some amount of work be it mechanical or cosmetic.

What you look for when buying a 5 might be totally different to what other people look for if you know what you can put right yourself relatively cheaply and what spares are available.


Other things to add in: Or delete.

Check for inner edge front tyre wear, especially if lowered, as this increases camber, and can be caused if the tracking has not been adjusted.

Exhaust, best for performance are the 2 1/4" or 2 1/2" full systems that are from the turbo backwards. No catalytic converter is required in these pre '91 cars. Such a free flowing exhaust lowers the back pressure after the turbo so the OE boost compensation system no longer works and may as well be removed and the holes plugged.

Clutch; heavy pedal with fierce bite = uprated clutch kit and no long release arm conversion. Cost is about £70?? Fitting costs £???

Play in steering? If the steering wheel has lateral or longitudinal play that would probably be the two column ball bearing bushes.

ECU over turbo? Is the Phase 1 layout and will damage the ECU leading to very uneven idle and pinking on lowish boost.

The turbo can jam due to oil burnt and set hard in it's bearings also causing no boost.

Dump Valve; they can leak leading to low boost.

OE actuator or weak actuator spring and bleed valve? Can lead to slow boost rise.

Harder springs and 15" wheels can lead to wheel bearing wearing out in only 12,000 miles.

OE anti percolation fan; noisy = worn. Unfused OE = fire risk if the fan jams.

White powder in tail pipe can mean over heating engine and possibly caused by blocked rad.

Some copper rads can leak. Bars leak can just block the rad and cause the engine to over heat.


Thinking out loud follows:
Big front discs are mainly for show but really for better cooling but can lead to poorer stopping as normally 20% of braking is from the rear tyres and bigger front discs lead to less pedal effort before the fronts lock so the rears are simply doing less.

Track lapping at race speeds with rock hard springs and shock settings and very sticky tyres means more weight transference and less rear braking.

With braided lines the pressure in the callipers is more immediate as there is no bulging like the rubber lines so the brake pedal travel is shorter to reach peak pressure. This means there can be locking of the front discs when applied suddenly compared to the OE lines. But there can be better pedal feel due to the reduction in sponginess.

Peak pressure in the callipers might be the same therefore also the same in the rears or it might be less if they just keep bulging until you run out of pedal travel.





ENGINE

The Renault 5 GT Turbo uses a heavily modified four cylinder, eight-valve “Cléon” (or C Series) 1397cc engine. The unit is of Pushrod OHV design that can trace it’s roots back to 1962. To cope with the rigours of turbo charging, it was fitted with hardened valve seats, compression ratio lowered 7.9:1 and heavier duty pistons with 13mm crown thickness. The engine utilised wet liners in a cast iron block which was a saving grace to many home modifiers meaning that if catastrophic engine damage occurred the entire piston & liner assemblies could be changed without even removing the engine from the car and the engine block did not become scrap.



Breather pipes; clean, with restrictors and working one way valves.
Mayo in header tank?
Low water in header tank?
Beige stains on hoses or engine? Could be leaking coolant.
Struggles to start?
water pump; leak / squeal = replace, half or whole.



CARBURETTOR

To control the air/fuel mix a Solex 32DIS single choke Carburettor is used rather than fuel injection so positively prehistoric compared to today’s modern cars which have sensors all over the car. This simple set up meant that the cars were easy to tune and increase the power by turning up the boost pressure. However if the carburettor was not tuned correctly the first you knew that something was wrong was that the Head Gasket failed. Thanks to the advance in wideband lambda sensor technology though it is easy to fit one and re-jet the carburettor to deliver the correct amount of fuel for the amount of boost pressure.

Group A and Group N are racing classes. The Group A Carb has a specially made taller venturi with a larger bore different jets and whilst some parts vendors in the 80’s / 90's may have sold an original group A carb there were only a handful of true Group spec carb’s in circulation. It soon became the case that they were selling a bored re-jetted standard carb and unknowing customers were wrongly called them, and re-selling them as, Group A. It’s safe to say that any Car advertised as having Group spec Carb means it’s just been re-jetted.

The re-jetting of the Carb requires a delicate touch and the knowledge of which parts to change/drill out otherwise you could end up over fuelling the engine which will not only give you poor fuel consumption but the fuel mixes with the oil and can rapidly wear the engine & turbo bearings and cause failure in a matter of weeks. A number of RTOC members have become very skilled in setting up the Carb’s and can tune them to give either big power or an increase in fuel consumption.

A common problem with the 5GTT is poor idling and this is usually down to a blocked idling jet, however it is possible for the base of the Carb to be warped and the throttle spindly seals to be ovalised and leaking air. The RTOC recommend that if the your car is running poorly that you re-build the Carb and ensure that everything is cleaned and working correctly. They sell a uniquely comprehensive re-build kit through their on-line shop and have informative and helpful re-build guides on their website.

TURBO

The GTT was originally fitted with a Garrett T2 Turbo and would run approximately 7 psi of boost and is a good mix of power and low Turbo-lag. It is possible to increase the boost pressure of the T2 Turbo to 14 psi at the manifold but that is the maximum the standard Carb & Cam can handle. This roughly equates to a 0-60 of 6.5 seconds in good weather conditions.

The next level of turbo would be a T25 or T28 enabling you to increase the boost pressure to circa 25 psi. Becoming a favourite is a Tomcat spec turbo, not an actual Tomcat turbo from and old Rover.

The downside with ever larger turbos is the ever greater lag between planting the loud pedal and the torque happening. For greater cost is a VNT turbo that spools much more quickly but still offers the large turbo benefits of lower back pressure and higher boost.
For road use you don't have to accept the off boost performance drop if you spend enough money and have a VNT together with a higher compression engine with redesigned combustion chambers and perhaps only 18psi boost and very careful tuning you get the best of both worlds with a much more linear torque delivery of 230ft lbs and still as much as 240bhp.

COOLING SYSTEM

Any increase in the boost pressure/performance of the car puts more load into the cooling system which unless it is properly maintained will lead to the car overheating and again possible head gasket issues. The RTOC state that the standard cooling system is more than up to the job as long as it is properly maintained. If the car seems to be running too hot it is recommended that the cooling system is fully flushed out with just water as some engine flushes have been known to block the waterways in the Turbo. The cooling fan should cut in as the gauge reaches the 3rd of 4 marks. Some people remove the Thermostats in the Top Radiator Hose near the water pump to help the cars run cooler but this can make the oil too cool to protect the engine as the Oil Cooler in the Radiator will be too cold. Better is to use a low temperature radiator fan switch.

GEARBOX

The GT turbo gearbox is of the JB series. Phase 1's were numbered 014 and the Phase 2's were 032 and are fairly robust. They utilise an electronic Speedo pickup which can be prone to connection problems and means that the speedometer does not run or record the mileage. You should check that the gearbox shifts smoothly & you can not hear any strange rumbling or whining during a test drive. A symptom of a tired gearbox is the fact that the car jumps out of 2nd, 3rd or 5th gear which means the unit is worn. Don’t be fobbed off by the seller telling you that “they all do that” and all it needs is a change of the engine mounts or adjustment of the gear linkage rod, you will probably need a replacement gearbox or a rebuild.

Another problem which can happen to the JB series gearbox is that a large circlip on the passenger side of the unit can snap and the differential just spins leaving you without any drive. Thankfully it’s relatively easy to change and, as they fit all JB series gearboxes, cheap to buy direct from Renault.

The 5GTT uses a JB3 and has the longest gears. Whilst it’s fine for plenty more then the original 120ft lbs, it can be a limiting factor for higher torque 5GTT’s. The bearings can fail after some time in moderately high powered cars. The JC5 box of the Clio has different bearings but may last no better than the GTT. If torque is high and traction is sufficient then it's the gears that break instead, and instantly. 1st gear is especially poor and the crown wheel can brake up and punch its way out of the casing. 1st gear would be a lot better if it was not made from brittle cast iron. Its not uncommon to have the diff pop out of place if the retaining circlip becomes unseated (sometimes tack welding this into place can fix that. Upgrading to a JC5 casing and bolt-in diff would be better.

JB5 is a 5 speed gearbox found on the NA's 5’s. It has a shorter case (bell housing to end cap) and narrower gears; much less strong than a JB3. JC5 is the Williams/172/182 unit and is the preferred gearbox, ratio's aside, because they nearly all come with a 4.07 final drive, which is a bit short for a typical GTT revving to 6500rpm. Put the final drive from the GTT's JB3 into a JC5 and you're onto a winner.

[Ian S]

CLUTCH

The clutch on the 5 GTT is known for being quite stiff to actuate but should still disengage before the pedal reaches the carpet. If you find yourself having to push the pedal almost through the floor of the car to disengage the clutch there is a problem. This first thing to do it to check the self adjust mechanism is not jammed but moving freely. If it is jammed then free it by pulling it toward the drivers seat in the correct way. It’s a ratchet situated just above the pedal.

Another cause might be a stretched clutch cable which could snap at any moment so replacement should be done ASAP before you are left stranded. However if the release mechanism is fully functional it will take up the slack.

Early on Renault changed the clutch pedal design to what is often known as the ‘White’ pedal due to it having white plastic instead of black. This should have been fitted in the recall but many weren’t. This more or less eliminated the problem of the clutch cable snapping every 6000 miles or so.

There are two clutch cables, one for the black pedal and one for the white. They are slightly different lengths.

Even with the clutch centre plate worn to the rivets the pedal will be at the correct height if the self adjust is working.

For much above standard torque, the RTOC recommend the Valeo Volvo 480???Turbo 3 piece clutch kit. When you are changing the clutch a sensible modification is to convert to the longer release lever and new pivot which will give you a softer clutch pedal with longer bite point which is much easier to use to feed the power in and also it reduces the risk of snapped cables with this harder sprung clutch.

The Group N clutch that you may have seen vendors selling is not an expensive special part but a standard clutch from another car. Was it always the case? The Group A clutch will be a more expensive item and there are a few suitable parts around to make up something if the Valeo Volvo clutch’s torque capacity is not enough, eg, if you’re making 230ft lbs, then the Valeo Volvo pressure plate can be used with a particular cerametallic paddle centre plate usually from AP racing

BODYWORK

The Supercinq was one of the first new Renaults in the 1980’s to be fully treated to a 5 stage anti corrosion process which means that they cars have stood up to the test of time rather well but there are a few common areas for rust to watch out for. The first & most easy to spot on a 5 is around the bottom edge of the windscreen or scuttle panel as it’s known. The five was fitted from the factory with a bonded in windscreen which needs to be cut out of the car to be replaced. As anyone who has had a windscreen replaced can testify the removal process is quite brutal and any scratches or damage to the paint/corrosion protection during this process gives the water a nice area to sit and eat the panel away. Up until recently you could still buy an entire panel from Renault replace the old rusted item however as the newest cars are 20 years old now Renault have stopped supplying the new panels so you need to get a body shop to fabricate repair patches now.

Another common area for rust on the 5 is the rear bumper brackets and this can only really be seen when the rear bumper is removed. The RTOC has managed to source a number of repair panels which have been specially manufactured to repair the corrosion in this area and they are available through their website. The final areas to check are the outer & inner sills & and the front jacking points which would cause an MOT fail. Thankfully both these parts are still available from Renault or third party panel suppliers. The work can cost £200 per side for a restoration repair.

The front doors can drop and become difficult to close because their hinges if not kept lubricated can corrode and wear away and it’s common now to have to fit new hinge pin and bushes on the newer version door or drill and fit specially made shims on the older versions.

BRAKES

Have any of you compared braided lines to NEW OE rubber lines? We all know braided are better than old OE rubber, but so it new OE rubber.

The standard brake set up on the 5 uses single pot Girling calipers around 238mm Vented disks and are quite adequate for both standard and mildly increased power outputs, but if the car is to be used on track day sessions the standard set-up will start to complain. It is recommended that the flexible brake lines are renewed if they are still the original rubber items as they can give a very soft pedal feel and not immediate enough braking.

The brake fluid should be replaced at regular intervals with a good standard DOT 4 type. (DOT 5 does not need to be considered unless you are fitting upgraded callipers etc).

The front discs can rust between, and occlude, the internal venting so replacement in this case should be considered.

There are a number of replacement pads on the market that claim to be better than original. Some don’t leave black residue and some are generally reckoned to be actually better. A favourite, although expensive, is the Ferodo DS2500.

You won’t need to worry about fitting better callipers although they are available. It is popular to fit larger diameter 285mm front discs together with calliper extender brackets but doing so will require change to larger than standard 13 inch wheels. Because it’s not realistically possibly to fit larger rear discs this can lead to an imbalance of braking with too little at the rear unless the rear compensator is turned on further by adjusting the rod toward the front of the car.

The rear brakes are solid discs that are moderated depending upon the passenger load by a compensation valve which in positioned in front of the rear axle. It is quite common for these brake compensators to seize up and stop working causing insufficient rear braking force and the car will fail it’s MOT. Usually you can un-seize the compensator with the help of some Plus-Gas but if it is rusted solid a replacement unit costs £130 if you can source one as they are becoming rare. Another issue is rusting of the discs and the brake pad retaining bracket which results in too little rear braking effort and will again cause an MOT failure.

The handbrake cable can be difficult to change as it jams in the rear callipers. There is an adjuster under the car to the correct handbrake height. The handbrake on the 5GTT is quite poor really and often a problem to get through the MOT.

WHEELS & TYRES

The 5 GT Turbo was supplied with 5½J13 inch Speedline alloy wheels wrapped in the 195 55/13 Michelin MXV Tyre specifically manufactured for the 5 GT Turbo. The custom sized tyre is now only supplied by Uniroyal in restricted numbers which means that some people have fitted the more commonly available 185/60 sized tyre but that does not give the same look to the car. Because of the strange size tyres becoming more expensive than those for larger wheels, many people fitted 15 inch wheels with the similar to OE overall diameter 195/45 or less expensive 195/50 tyres. One benefit from the 15 wheels and lower profile tyres is the extra grip these can provide leading to sharper steering, turn in braking and reducing wheel spin.

SUSPENSION

When I got my 5GTT in 1992 at 54,000 miles the shocks were possibly needing replacing. The cornering was rubbish compared to all the previous cars I’d driven. Have any of you compared new OE to old OE to see if that sharpens up the handling? Or was the OE actually just rubbish?

McPherson front struts with anti roll bar. Rear trailing arms with torsion bars / anti roll bars.

Many people felt the original front suspension from Renault was not very good and the car tended to bounce and skip and judder through corners with one end then the other stepping out and back lolling over then pulling the front over. Renault used fairly soft springs and a quite hard bump setting on the shock absorbers. This gave a hard ride and made for a difficult and unpleasant drive.

It was exacerbated by the very soft and squashy tyres that didn’t exactly confer a sharp handling response but at least they did soften the bumps a bit.

A vast improvement was to bin the OE and fit a Koni ‘yellow’ shock absorber and harder springs kit. Sometimes those kits just have lowering springs, but the car needs at least 175lb / inch to dramatically improve the turn in and general cornering. Some people use 250 or even 300lb/inch. Different to what one might expect, the Koni kit gives a softer ride than the OE even though it eliminates the ‘boaty’ sloppy ride and replaces it with a taught and driveable one.

Fitting 15 inch wheels with 195 45 15 tyres also sharpens the steering, increases the turn in bite and general grip. They do make the ride harder. Whilst the radius is only about 5mm more that with the original 13 inch wheels, height at the front from hub to road is 10mm more due to less tyre squash than the OE and 5mm higher at the rear and the car does begin to look like an ‘off roader’ so lowering is in normally done just to get down the original ground clearance.

The front suspension geometry is designed to keep both front tyres flatter to the road surface while the car rolls; the outer wheel gains more camber and the inner wheel loses some. Lowering the front can adversely affect this, reducing the grip and upsetting the handling. Fitting harder springs might reduce this by reducing the roll.

Camber adjusters are sometimes fitted to the front to try and provide more grip. These can cause inner edge tyre wear.

Another thing that should be at the top of the list of faults to check for is worn suspension turrets. These allow the front springs and shock to move side to side and front to back and make the car very difficult to steer in a straight line. Often it can be cured by changing only the rubber ‘doughnut’, but sometimes there is wear to the metal parts too if the fault has been left for too long.

There are polyurethane replacement bushes for the front wish bones and anti roll bar. Good quality ones of these can tighten up the steering response but new OE might be fine.

When harder springs are fitted the ball joints, track rod ends and front wheel bearings can wear quickly.

The car responds quite well to the fitting of a front strut brace as it will steady the car during hard tight cornering.

Some people will have fitted variable ride height front shock absorbers to either lower the car further than can be done with standard sized shocks or to have suspension that barely moves at all.

Lowering the rear is accomplished by partially removing, turning and refitting the rear torsion bars. The 5GTT sits a bit higher at the rear and lowering this a bit extra is felt by some to improve the cornering. This could be for no reason other than due to removal of sufficient clearance up to the rear shock absorber bump stops. This can reduce rear roll and work well on smooth roads but does quickly destroy the rear standard shocks and some after market shocks which can be seen leaking. It can also make an excessively hard ride over larger bumps that can hurt the drivers back and bounce the car nearly off the road on a narrow lane fast corner and one simply has to drive slower. If you want to make good progress in the countryside then you need rear suspension travel.

Some people feel that with the small standard sized wheels the cars look as though they have too much arch clearance and like to lower the cars to improve the look; Steve’s car pictured here is lowered by 35mm at the front.

STEERING

Most of this is covered in 'suspension'.
The buyer should be aware that on most years of 5GTT there was fitted a rubber lined universal joint at the bottom of the steering column which can provide excessive slack in the steering. It's fairly quick and easy to change this for a new one. If the steering wheel is rubbing on the fascia then it's been re-fitted to low; this is also easy to adjust back to it's correct height. To low can also cause the steering lock to jam on and not be released by the ignition key.

INTERIOR

The interior of the car is fairly hard wearing but the first part to go is the outer side bolsters from the bucketed front seats. New bolsters are still available from Renault at a cost of £80 but many second hand replacements are available on the internet. Original gear knobs are no-longer available from Renault so if you are looking for one to restore a car a new gear knob is something you will struggle to obtain.

The electric windows are known for being quite slow to actuate and this is usually caused by worn/tired motors & perished rubber guides. Some time spent cleaning & re-greasing everything can improve the situation. The Central door locks are also known for being somewhat un-reliable but replacements can be found. Sometimes the cause for slow windows and central locks is corroded electrical connectors that fail to pass adequate current to operate them.

The carpet should be checked for dampness as water can leak into the interior through a rusting scuttle panel, around the windscreen if it’s come away from the bonding, around the rear side windows and the through the doors if their inner seal under the door card has not been re-applied. It can also track in via the door speaker baskets

Coolant can leak out of the heater matrix, the latter meaning the dashboard has to come out to change which was listed at Renault as a 10 hour job and about the most expensive service item.

The bolts that couple the front seats to their sub frames come lose and need tightening from time to time.

POWER/TUNING

The Phase 2 5 GT Turbo left the factory with 120 BHP which does not seem very high now compared to many modern cars, however as the car is very light at 830kg so the power to weight ratio is quite high and a moderate increase in power can give impressive results. Many people strive to reach 200 BHP and to achieve this, the RTOC recommend the following modifications:

· Correctly re-Jetted standard venturi’d carburettor set for 20 to 25psi of boost.
· Free flowing exhaust with larger bore from the turbo back all the way through to the tail pipe. Not one with a restrictor or narrow baffle.
· T25 or T28 Turbo set to 20 to 25 psi; a favourite is the ‘Tomcat Spec’ not the actual Tomcat turbo. The larger the turbo the more power and the more lag.
· Stronger actuator, preferably the T3 type with a -12 spring.
· Actuator piping changed to the ‘Cup Racing Series’ Modification.
· Delete the rest of the boost compensation mechanism as it has no effect once a decent low back pressure exhaust is fitted.
· Boost gauge to read manifold boost pressure or you’ve no clue what boost you have as the OE dash gauge reads the pressure before the carb.
· Larger than OE intercooler with alloy welded on end tanks and generally front mounted.
· Different camshaft profile, a favourite is the 285 @ 110°.
· Stronger clutch, normally the Valeo Volvo 480T. (Soft pedal conversion will extend clutch cable life)
· Firmer engine mounts to check the extra engine movement.
· Normally silicone boost hoses and new OE or silicone water hoses as old OE items tend to split. For reliability this applies even if you’re keeping standard power.
· Old pressure gauge to show you the reading at the inlet to the turbo.
· Adjustable bracket for top dead centre sensor to allow timing to be backed off a few degrees.
· Bottom pulley from a Campus engine; it’s smaller diameter turns the alternator / water pump slower and doesn’t throw off the belt on sudden lowering of high engine rpm.
· For long term turbo reliability, not noise, a double piston dump valve, possibly re-circulating for no noise at all. Double piston as they keep the inlet pressure up when off boost giving more responsive get up and go.

To give you some idea as to how tuneable the GT Turbo is, the RTOC hold an annual Drag event every year at Santa Pod and the current ¼ Mile record holder, Glenn Robson, ran an amazing 11.2 second quarter mile in 2010 all be it with the addition of NOS.

[Josie172cup]

i've only had a quick scan through, it seams a good read. Only thing i would add would be something to do with the availability of parts like how you can get basically anything basically nothing. This was one of the reasons i bought one.


sorry if this was no help

[Eugein Offord]

looks cool Ian and what a great oppotunity for the club to get some free advertiseing , But..... i think its a tunning guide you've writen..............i think Although many gtts have been modded... i think most people will be looking and wanting fairly standard cars.........the refernce to the circlip on the gearbox is a bit extrem .. considering most peple wont go to santa Pod with boost..........we all know the cars con be adapted to suit all tastes and wallets, maybe a simple mention of marketed "upgrades" would suffice... the joy of driving a normal, reliable, quiet and still nippy 5 gt turbo shouldn't be undervalued..............

[Trevhib]

Top work Ian, as ever.

I haven't read every word so apologies if any of my suggestions are already catered for.

You need to proof read it, there are a number of language and spelling issues. It's late and I'm going to bed so I'm not going to list the ones I've seen this evening

Suggestions:

- Links to further information (such as the ph1/2 differences list and other information we have on the site that's available to non-members).

- Pictures (always say a thousand words)

- Price range advice

- Debunk myths section - to include Raider misconceptions, sunroofs not from the factory, 1.7 engines, etc

- Colour options? UK vs Europe?

- Odd/interesting facts section - Jap aircon, special editions, museum locations, annual Renault events, popularity of GTT's in places like Netherlands etc etc?

Just thoughts.

[TrixNFlix]

Great read, but how much do you reckon they will put in the mag, my guess is not much.

[Alastair]

Ian,

[Trevhib]

Great read, but how much do you reckon they will put in the mag, my guess is not much.

This might not matter so much as we can use the buying guide in its complete form for the RTOC website.

[Alastair]

Ian, top work as ever. I have had a go taking into account the points above and tried to focus on a buyers guide slant using your work so far.
I think we should limit the info we provide on tuning so peeps have to join the club to get the tech info... Only half way through this but if peeps think it worthwhile i will crack on with the rest tomorrow night (4 hrs ahead here)... please let me know!
Oh and i havent proof read any of it yet, just blatted it out! Big thanks to Ian for sorting us out again too, lots of typing there mate!!!

RTOC RENAULT 5 GT TURBO BUYING GUIDE

This month the buying guide is on thecult Hot Hatch, the Renault 5 GT Turbo. Back in the late 80’s & early 90’s these cars were many young man’s dream and were slugging it out with Peugeot 205 & VW Golf GTI’s around every ring road & leisure centre car park. There have been many buying guides for these cars over the years, giving differing recommendations on what’s right & wrong. However this time Performance French Cars have created a buying guide in conjunction with the Renault Turbo Owners Club (www.rtoc.org) to ensure that you are provided with the most accurate and comprehensive guide so far.

Over the last 25 years the Renault 5 has maintainedit’s appeal to many car enthusiasts, not only because it has competed and won in various racing series, been popular for fast road use and is very responsive to chassis tuning but also the focus for many years as a styling icon for hot hatches with modification from the sensible to the extreme. It seems the inherent appeal of these cars is the lightweight nimbleness, coupled with great driver feedback, and it’s ability to put a huge smile on anyone’s face when the turbo comes on boost

Many people remember the Ali-G big wheels & body kit scene of the nineties which tarnished the reputation of the 5 GT Turbo in the minds of the RTOC. In more recent years though, there has been a shift in restoring cars back to factory fresh OE looking examples as illustrated by Big Steve’s stunning Raider pictured here.

HISTORY

The Renault 5 was launched in 1972 and spawned many performance versions from the Turbocharged Gordini, to the wide body RWD Turbo I in 1980 that won the 1981 Monte Carlo rally, the Turbo II in 1983 and the Maxi in 1985 of which only 20 were made. In total only 5007 RWD T1, T2 and Maxi were made.

The second generation Supercinq (Super Five) was launched in 1985 and was styled by Marcello Gandini who had previously penned the Lamborghini Countach. The chassis was based on the Renault 9/11 models with McPherson strut front suspension and transverse engine and gearbox, but the Renault 5 styling trademarks were retained.

When the Supercinq was launched the GT Turbo was not offered for sale but was included in the brochure as the “Coupe” model. This Coupe model was described as being developed for racing only and not available for sale, but by 1986 the GT Turbo was launched with a price tag of £7,710. Producing 115bhp, it was fitted with a slightly different body kit to the one shown here.

In 1987 Renault made a number of small but significant changes and designated it the phase 2 model. Most obvious was the painted and smoothed body kit that reduced the car's drag coefficient from 0.36 to 0.35, different wheels and seat cloth, and a more comprehensive centre console. Under the bonnet were some improvements to address reliability because the Phase 1 suffered hot starting problems. Renault added anautomatic anti percolation fan to cool the carburettor, turbo compressor and intercooler. A water cooled turbo charger in lieu of an air cooled unit, and re-plumbed the cooling system. The power increased by 5 BHP to 120 BHP thanks to a more aggressive ignition map programmed within the ‘ECU’.The ECU was also relocated from above the turbo to within the scuttle area to avoid heat damage. In 1990/91 the throttle cable to the carburettorwas re-routed and the steering column UJ was replaced with a more direct feeling metal item. Door cards were given a corduroy cloth cover, and additional sound proofing was added with a boot light included as a luxury touch! In late 1991 the 5 GT Turbo was discontinued, with the last year of production sold on H plates, although there are a few J and K reg cars around, these were not manufactured at a later date, just stored cars sold by Dealerships at a later date.

There are approximately 3500 GT Turbo’s still registered with the DVLA and with the newest cars now 20 years old parts are becoming harder to source as Renault gradually withdraw components from there stock lists. However, due to the fanatical following and a number of specialists, there are very few parts that are truly unobtainable.

Advice

There are very few GT Turbo’s that will not require some form of work. Be careful to avoid very rusty or poorly modified examples, as even with a lower purchase cost, it will probably cost more to return it to a reliable, enjoyable car than buying a better example in the first place.

SHELL / BODYWORK

The Supercinq was one of the first new Renaults in the 1980’s to be fully treated to a 5 stage anti corrosion process, which means that these cars have stood up to twenty plus years of British weather rather well, but there are a few common areas for rust to watch out for. As with all older cars it pays to get it on a ramp to have a good look underneath.

The first & most easy to spot area for corrosionto set in is around the bottom edge of the windscreen. The 5 was fitted from the factory with a bonded in windscreen which needs to be cut out of the car to be replaced. The removal process uses a cheese wire or scalpel, and any scratches or damage to the paint underneath the bonding agent during this process accelerates corrosion. Repair panels are no longer available from Renault leaving your only option a repair patch. You can check the condition of this area by running you hand under the lower windscreen area from within the scuttle. There are two small drainage holes at each lower corner of the screen where corrosion usually starts.

Another common rusty area is the front and rear bumper mounting points. As these are hidden by the bumpers and arches can really only be seen with the bumpers removed. The RTOC has managed to source a number of repair panels which have been specially manufactured to replace corroded panels in these areas and they are available through their website. The other main areas to check are the outer & inner sills (again hidden by the body kit) and the front jacking points that link the inner sill to the front chassis rail which are an MOT fail. Thankfully all of these parts are available from Renault or third party panel suppliers, budget up to £300 per side for a full repair. Also check the floor panel drainage plugs, where it folds up around the fuel tank, and the boot floor where it meets the rear arches.

The front doors can drop to give unsightly shut lines, and become difficult to close if their hinges are not kept lubricated. This allows the bottom corner of the door to catch the sill and promotes rust. It is easy enough to fit a new hinge pin and bushes on the newer version door, or to drill and fit shims on the older versions.


INTERIOR

The interior of the car is comfortable and ergonomically designed, GT Turbos were fitted with a black vinyl covered dashboard instead of the standard hard grey plastic. In general the whole interior is fairly hard wearing but the front seat side bolsters wear and the foam breaks down. New bolsters are still available from Renault and cheaper re-pro replacements are available on the internet. Also check that the OE front seats do not rock on their latches,this will at best irritate you when driving quickly, or be a time consuming and fiddly fix with a welder and DIY bushes.

Original gear knobs are no-longer available from Renault and command a premium price.

The electric windows are known for being slow, this is caused by motors with old dried out grease & perished rubber guides. Some time spent cleaning & re-greasing the mechanism can vastly improve the situation. The central locking motors are cheap second hand and easy to replace if sticking. It is also worth cleaning the OE electrical connections within the doors.

Check the carpet for dampness in the foot wells as water can leak from a rusting scuttle panel around the windscreen, floor panel plugs, or a leaking heater matrix. The dashboard needs to be removed to change the heater matrix and whilst not an expensive item itself, it is a very time consuming job and will likely require a new set of dashboard clips to prevent rattles on re-fitment.

WHEELS & TYRES

The 5 GT Turbo was supplied with 5.5J 13 inch Speedline alloy wheels wrapped in 195 55/13 Michelin MXV Tyres specifically manufactured for the 5 GT Turbo. This custom sized tyre is now only supplied by Uniroyal in restricted numbers and some people fit 185/60 sized tyres instead. Unfortunately this degrades handling and does not give the same look to the car. Many people fit 15” wheels with 195/45/15 tyres similar in overall diameter to the MXV, or less expensive 195/50 tyres which again are a poor choice for a performance car. The 15 wheels and lower profile tyres offer extra grip over the MXV, and give sharper steering, turn in, braking and reduce wheel spin, they also allow bigger brakes to be fitted. Standard 13” wheels are commonplace and cheap if you wish to go for the OE look. Avoid cars using large wheel spacers as this will cause lots of torque and bump steer, unless you plan to change the wheels

BRAKES

Have any of you compared braided lines to NEW OE rubber lines? We all know braided are better than old OE rubber, but so it new OE rubber.

The standard brake set up uses single pot Girling calipers and 238mm vented disks and are quite adequate for both standard and mildly increased power outputs, before buying make sure that all four callipers are free and that all the bleed nipples are not snapped off, and that the rear spring-tensioned proportioning valve is free to move (circa £130). However, don’t be put off a car with iffy brakes as all components are relatively cheap, except for the brake servo unit which comes in at around £250. If the car is to be used on track then the OE set-up will suffer from fadewithout decent quality pads and disks. RTOC recommend Ferrodo DS2500 or Mintex 1144 as these have been used with great success in the various R5 race series during the 90s.

A popular upgrade is to fit 285mm front discs together with calliper extender brackets (requires 15” wheels), along with braided brake lines, don’t let this put you off even though many consider it unnecessary. You won’t need to worry about fitting better callipers although they are available for the most extreme applications.

The rear brakes are solid discs and are generally reliable if the car is not left for long periods, however the handbrake will require regular attention, particularly before MoT time.


1 of 2

[Alastair]

STEERING

On most 5 GTT’s there was a rubber lined universal joint at the bottom of the steering column which wears out over time and gives excessive play in the steering. This is rather disconcerting to a potential buyer but it is a fairly quick and easy change. Also if the steering wheel is rubbing on the fascia then it's been re-fitted to low and it is easy to adjust back to it's correct height, this can also cause the steering lock to jam on and not be released by the ignition key. Steering racks are generally bullet proof.

SUSPENSION

When I got my 5GTT in 1992 at 54,000 miles the shocks were possibly needing replacing. The cornering was rubbish compared to all the previous cars I’d driven. Have any of you compared new OE to old OE to see if that sharpens up the handling? Or was the OE actually just rubbish?

The supercinq was a big advance compared to the old R5, with McPherson front struts and anti roll bar, and rear trailing arms with torsion bars and anti roll bars.

Many people feel the original front suspension from Renault was too soft and the car tended to bounce and roll excessively through corners. Renault used fairly soft springs and a quite hard bump setting on the shock absorbers. This gave a comfortable ride when cruising, but compromised the cars handling at this limits of grip from the MXV tyres.


Almost all cars on the market will have been fitted with some form of upgraded suspension, and almost certainly lowered. Check for cut down standard springs, leaking shocks and worn suspension bushes. Any knocks or rattles on a test drive should be investigated and used as a negotiating point over price. Often the front strut top mount bearings seize and cause play. This, if left unchecked, can destroy the top bushes and mounting plates which are now no longer available new, but refurbished parts are still available.

On any lowered car check that there is not excessive negative camber, as this will destroy your tyres and wheel bearings and compromise road holding. 1 – 1.5 degrees negative camber is normal. Camber correcting bolts are cheap and commonly available.

Wishbone and ARB bushes are also prone to wear on hard driven cars, and cripple the handling, giving a distant feel through the steering wheel, and poor directional stability at speed. However OE and polyurethane replacements are cheap and easy to replace.

The car responds quite well to the fitting of a front strut brace as it will steady the car during hard cornering, view this as a bonus if included in the sale.

A well maintained car will have had a quality spring and damper combination fitted by now. The most popular is a Koni ‘yellow’ shock absorber and spring kit which retail for around £400, fitment is a quick and easy job. The car needs at least 175lb / inch to improve the turn in and general cornering, however avoid anything approaching 250 lb/inch for every day use if you don’t want to suffer from a bad back. Different to what one might expect, the Koni kit gives a softer ride than the OE even though it reduces body roll.


Lowering the rear is accomplished by partially removing, turning and refitting the rear torsion bars. If you plan to make any changes to the offered cars ride height investigate when they were last removed as they commonly seize and require lots of work to free them up. You can quickly check condition by removing the black plastic cap on the end of the rear beam under the arch, any corrosion or a damaged thread into the torsion bar and you may have to replace the beam, lots of copper slip is a good sign.

Rear shock absorbers wear quickly on lowered cars and benefit from progressive bump stops.

Some people feel that with the small standard sized wheels the cars look as though they have too much arch clearance and like to lower the cars to improve the look; Steve’s car pictured here is lowered by 35mm at the front.


ENGINE

The Renault 5 GT Turbo uses a heavily modified four cylinder, eight-valve “Cléon” (or C Series) 1397cc engine. The unit is a Pushrod OHV design that can trace it’s roots back to 1962. To cope with the rigours of turbo charging, it was fitted with hardened valve seats, the compression ratio lowered 7.9:1 and heavy duty pistons with a 13mm crown thickness. The engine uses wet liners in a cast iron block meaning that the entire piston & liner assemblies can be changed without removing the engine from the car. The C1J engine is what gives this car most of its character.

A common misconception is that the engine and particularly the head gasket is unreliable. In reality quite the opposite is true if a few golden rules are followed. This bad press came about because owners in the 90s were upping boost pressure without adjusting the fuelling within the carburettor, resulting in immediate detonation and H/G failure. An engine that has had vaguely regular servicing and maintains a good oil pressure will easily survive to 150k miles before rings, main bearings or valve guides need replacing, even when run well above standard boost. Many RTOC owners run 20 year old, totally standard engines up to 180 bhp for every day use without any problems, and 200+ bhp is also easily achieved with mild cams and even bigger turbos. The key to reliability is in accurate fuel set-up, and using super unleaded to prevent detonation.

When buying check what boost is being run, and ask lots of questions about the fuelling set up, a knowledgeable owners club car will have had lots of attention in this area. A wide band lambda sensor and gauge is essential for any car running a bar of boost or more and should not put you off. Once set up you can remove this for an OE look, but remember to check fuelling regularly.

Always view the car started from cold. Make sure it idles correctly on the choke with very little smoke, white condensation is fine. Once warm ensure the fan starts and stops automatically without the temperature going over the third notch on the dashboard. Then take it for a drive and check for black or blue smoke on boost, or when backing off the throttle. Ensure you drive for at least 15 minutes and on return check to see if the owner lets it idle to let the turbo spin down before turning it off – a very good sign. Whilst still fairly hot, remove the oil filler cap and oil dip stick to check for mayonnaise, and lok for changes to the coolant header tank level, oil in the coolant is a bad sign! If the anti-percolation fan doesn’t start automatically do not panic, they are often temperamental and require regular attention to the loom, heat sensors and fan unit. Squealing from the fan belt can indicate a water pump that is tired; replacements are cheap and easy to do.

Another popular modification is to simplify the breather system, ensure that this has been done properly in accordance with the Renault ‘Cup’ series advice, a 2 litre catch tank is a must, avoid ones that are too small. Otherwise check all the coolant and breather pipes for damage, they often rub together and burst if not retained in the OE clips, or cable tied together. Also check the bleed nipples are in good order, brass replacements are available for the plastic type plugs and are a wise investment for a fiver. Silicone replacements are another popular upgrade, however check for cheap Chinese copies which are inferior, SFS and Samco have a good reputation.

CARBURETTOR

To control the fueling a Solex 32DIS single choke Carburettor is used rather than fuel injection. This is positively prehistoric compared to today’s modern cars which have sensors everywhere. However this simple set up means that the cars are easy and cheap to tune. Thanks to the advance in wideband lambda sensor technology it is easy to re-jet the carburettor to deliver the correct amount of fuel for any increase in boost pressure.

Group A and Group N are racing classes, and genuine racing parts are extremely rare. The so called Group A Carb as sold by tuners is best avoided as they are usually just a bored out venture which fuels excessively rich at part throttle. Look for a car with a recently serviced carburettor that has had lots of attention paid to the set up.

Re-jetting of the Carb requires a delicate touch and detailed knowledge of which parts to drill out, otherwise you will ruin your carburettor, and over fuel the engine. A number of RTOC members have become very skilled in setting up the Carb’s and can tune them to give either big power or much improved fuel consumption, many of whom only charge a cup of tea for their services.

A common problem with the 5GTT is poor idling, this is usually down to a blocked idle jet, however it is possible for the base of the Carb to be warped and the throttle spindly seals to be ovalised and leaking air. Replacement carburettors are all 20 years old now and will require a minimum of a new seal and gasket kit available for approx £30. RTOC sell a comprehensive re-build kit through their on-line shop and have detailed re-build guides on the website.

TURBOS

The GTT was originally fitted with a Garrett T2 Turbo and runs 7 psi of boost. This offers a good mix of power and low Turbo-lag. It is possible to increase the boost pressure of the T2 Turbo up to an absoloute maximum of 14 psi at the manifold, but OE turbos will not last long at this level. These turbos are particularly sensitive to dirty oil.

Most cars are now fitted with a larger T25 or T28 turbo enabling an increase in boost pressure up to 20+ psi. A favourite is a Tomcat spec turbo, from the Rover 200 series. If you intend to use the car every day these larger turbos do give more lag, but flow better for higher top end power output. Ideally look for a roller bearing replacement turbo, these are very hardy and give less lag, but can cost up to £1k! VNT turbos are becoming popular but are even more difficult to set up correctly.

[djinuk]

i would maybe pay particualar mention to the fact that these cars are prone to rust.

Sills, inner sills, jacking points, rear boot areas.. rear tailgate..


Personally i find people are generally happy to swap engines and spend mega wedge on reaplacing duff engine parts, but as soon as a car fails mot on rust (sills) they rapidly talk about breaking/scrapping... i personally feel this is more important than anything and would take centre stage for me when advising on cars to buy..

[Josie172cup]

i would maybe pay particualar mention to the fact that these cars are prone to rust.

Sills, inner sills, jacking points, rear boot areas.. rear tailgate..


Personally i find people are generally happy to swap engines and spend mega wedge on reaplacing duff engine parts, but as soon as a car fails mot on rust (sills) they rapidly talk about breaking/scrapping... i personally feel this is more important than anything and would take centre stage for me when advising on cars to buy..

[Hoolio]

That really is a great bit of work but surely you need to keep it to the basics make it much shorter and link again and again to the site for more information, talking specifics like the gear knobis interesting for us and useful but probably not needed for the article.

[TrixNFlix]

That really is a great bit of work but surely you need to keep it to the basics make it much shorter and link again and again to the site for more information, talking specifics like the gear knobis interesting for us and useful but probably not needed for the article.

As said earlier by Trev aswell, this is perfect for our club as an article, but probably wont be what the mag is after.

[Trevhib]

I think what I meant was that this is perfect for the RTOC website in full, AND is perfect to offer to the mag for them to then either accept OR request editing down. Better to have too much info and then, if necessary, just strip it out (than not have enough data and have to add in bit-part).

I agree that certain things should maybe be cut down a bit adding in the article that 'further information is available by becoming an RTOC member'. Depends what the club is happy/agreed to offer up.

Alistair - brilliant additions.

I'd suggest replacing 'ECU' with 'ingition unit' (or similar) anywhere it appears.

[TNT ANDY]

I would disagree with the advise to up to a roller bearing turbo on anything less than a T3. I have been told by CR turbo's they will pull out about 200 rpm at best on small frame turbo's. Anything big it's a no brainer and roller bearing turbo's reap more benefits.

[Ian S]

Thanks all for your praise Should be extended to others as named below, and now Alistair, that's for your large effort I spent many hours, 'til 4am last night, collating just the first part of the double post. Plan to get on with the 2nd part today.

availability of parts like how you can get basically anything basically nothing

OK, thanks.

its a tuning guide you've written..many gtts have been mod'd most people looking for standard cars.... the joy of driving a normal, reliable, quiet and still nippy 5 gt turbo shouldn't be undervalued.

Good points. It was written by Big Steve, Sparkie, Scoff and me, so not surprisingly mentions the value of good mod's. I've haven't had a standard 5GTT since 1993. Now is biased more toward a new buyer

- Links to further information (such as the ph1/2 differences list and other information we have on the site that's available to non-members).

- Pictures (always say a thousand words)

- Price range advice

- Debunk myths section - to include Raider misconceptions, sunroofs not from the factory, 1.7 engines, etc

- Colour options? UK vs Europe?

- Odd/interesting facts section - Jap aircon, special editions, museum locations, annual Renault events, popularity of GTT's in places like Netherlands etc etc?

Just thoughts.

Good ones, thanks. I just can't do it all, too slow as too badly dyslexic! Would be very good if someone / people could find and expand on these so I could try and splice them into what we have.

pay particular mention to the rust.

Sills, inner sills, jacking points, rear boot areas.. rear tailgate..

Done

keep it to the basics make it much shorter and link again and again to the site for more information

PFC want as much detail as possible. It's a paper magazine; no point in having links to the site that readers, mostly non members, can't use.

this is perfect for the RTOC website in full, AND is perfect to offer to the mag for them to then either accept OR request editing down.

I agree.

I'd suggest replacing 'ECU' with 'ignition unit' (or similar) anywhere it appears.

OK.

I would disagree with the advise to up to a roller bearing turbo on anything less than a T3. I have been told by CR turbo's they will pull out about 200 rpm at best on small frame turbo's. Anything big it's a no brainer and roller bearing turbo's reap more benefits.

Thanks .

[Alastair]

Ian, top work mate , i had a quick go through the rest but not a lot to add, and not a lot of time i am afraid! Hope they like it and it gets published. Got to dash, rather busy out here, but this takes my mind off stuff!

[Alastair]

Top work Ian, I had a quick run through the last bit, but very tired and need to get back on duty... so didnt have a lot of time, looks really good mate. BZ


COOLING SYSTEM

Any increase in the boost pressure/performance of the car puts more load into the cooling system which unless it is properly maintained will lead to the car overheating and again possible head gasket issues. The RTOC state that the standard cooling system is more than up to the job as long as it is properly maintained. If the car seems to be running too hot it is probably a partially occluded radiator or a buld up of silt within the system. Once the cooling system is fully thoroughly flushed out, and the water pump checked for a good flow ratemost overheating problems will disappear. Be carefule to use only water as some engine flushes have been known to block turbocharger waterways. The cooling fan should cut in as the gauge reaches the 3rd of 4 marks. Some people remove the thermostat in the top radiator hose near the water pump in a vain attempt to help cars run cooler, however this can cause cavitation within the water pump, erosion within the cylinder head and over cool engine Oil during warm up as the oil cooler is part of the radiator. It is better to use a low temperature radiator fan switch, and drill a 4mm hole in the top of the thermostat to aid coolant system bleeding.

GEARBOX

The GT turbo gearbox is a JB series box. Phase 1's were numbered 014 and the Phase 2's were 032 and are fairly robust. They utilise an electronic Speedo pickup which can be prone to connection problems and means that the speedometer does not run or record the mileage. You should check that the gearbox shifts smoothly and that you can not hear any strange rumbling or whining during a test drive. A symptom of a tired gearbox is the fact that the car jumps out of 2nd, 3rd or 5th gear particularly when backing off the throttle which means the unit is worn, or the main retaining nut on the lay shaft is lose. Don’t be fobbed off by the seller telling you that “they all do that” and all it needs is a change of the engine mounts or adjustment of the gear linkage rod, if this is the case you will probably need a replacement gearbox or a rebuild, which is engine out time.

Another problem which can happen to the JB series gearbox is that a large circlip on the passenger side of the unit can snap and the differential just spins leaving you without any drive. Thankfully it’s relatively easy to change and, as they fit all JB series gearboxes, cheap to buy direct from Renault.

The 5GTT uses a JB3 and has the longest gears. Whilst it’s fine for plenty more then the original 120ft lbs, it can be a limiting factor for higher torque 5GTT’s. The bearings can fail after some time in moderately high powered cars. The JC5 box from a Clio has different bearings but there are conflicting reports as to their longevity when compared to the JB3. If torque is high and traction is sufficient then the gears often break instead. 1st gear is especially poor and the crown wheel can brake up and punch its way out of the casing as it is made from a brittle cast iron. Its not uncommon to have the diff pop out of place if the retaining circlip becomes unseated (sometimes tack welding this into place can fix it. Upgrading to a JC5 casing and bolt-in diff would be better.

JB5 is a 5 speed gearbox found on the NA's 5’s. It has a shorter case (bell housing to end cap) and narrower gears; and is much less strong than a JB3. JC5 is the Williams/172/182 unit and is the preferred gearbox, ratio's aside, because they nearly all come with a 4.07 final drive, which is a bit short for a typical GTT revving to 6500rpm. Put the final drive from the GTT's JB3 into a JC5 and you're onto a winner.


CLUTCH

The clutch on the 5 GTT is known for being quite stiff to actuate but should still disengage before the pedal reaches the carpet. If you find yourself having to push the pedal almost through the floor of the car to disengage the clutch there is a problem. This first thing to do it to check the self adjusting mechanism is not jammed but moving freely. If it is jammed then free it by pulling it toward the drivers seat, it is only a simple ratchet situated just above the pedal.

Another cause might be a stretched clutch cable, OE cables are much higher quality than pattern parts which frequently snap, particularly when routed incorrectly. A stretched cable should be done ASAP before you are left stranded. However if the release mechanism is fully functional it will take up the slack.

Early on Renault changed the clutch pedal design to what is often known as the ‘White’ pedal due to it having white plastic instead of black. This should have been fitted in the recall but many weren’t. This more or less eliminated the problem of the clutch cable snapping every 6000 miles or so.

There are two clutch cables, one for the black pedal and one for the white. They are slightly different lengths. However it is difficult to tell which you have fitted, and even with the clutch centre plate worn to the rivets the pedal will be at the correct height if the self adjust is working properly.

For much above standard torque, the RTOC recommend the Valeo Volvo 480 Turbo 3 piece clutch kit, it is capable of handling all but the most powerful GT Turbos out there, and is relatively cheap. When you are changing the clutch a sensible modification is to convert to the longer release lever and new pivot which will give you a softer clutch pedal with longer bite point which is much easier to use to feed the power in and also it reduces the risk of snapped cables with this harder sprung clutch.

The Group N clutch that you may have seen vendors selling is not an expensive special part but a standard clutch from another car. Was it always the case? The Group A clutch will be a more expensive item and there are a few suitable parts around to make up something if the Valeo Volvo clutch’s torque capacity is not enough, eg, if you’re making 230ft lbs, then the Valeo Volvo pressure plate can be used with a cerametallic paddle centre plate from AP racing or similar, however these do not last long on a road car and can cause judder on take up.






Tuning?

The Phase 2 5 GT Turbo left the factory with 120 BHP which does not seem very high now compared to many modern cars, however as the car is very light at 830kg the power to weight ratio is quite high and a moderate increase in power can give impressive results. Many people strive to reach 200 BHP and to achieve this, the RTOC recommend the following modifications:


Is the below selling off the family silver? Perhaps we limit the content to general stuff and make them join the club for the detail:
Assuming you start with a standard car the first port of call for more performance is a decent air filter element, exhaust and downpipe, uprated clutch, uprated turbo, better intercooling and then crucially adjusting the fuelling within the carb correctly. Doing this should see upwards of 180 bhp and a reliable, hugely fun hot hatch.

· Correctly re-Jetted standard venturi’d carburettor set for 20 to 25psi of boost.
· Free flowing exhaust with larger bore from the turbo back all the way through to the tail pipe. Not one with a restrictor or narrow baffle.
· T25 or T28 Turbo set to 20 to 25 psi; a favourite is the ‘Tomcat Spec’ not the actual Tomcat turbo. The larger the turbo the more power and the more lag.
· Stronger actuator, preferably the T3 type with a -12 spring.
· Actuator piping changed to the ‘Cup Racing Series’ Modification.
· Delete the rest of the boost compensation mechanism as it has no effect once a decent low back pressure exhaust is fitted.
· Boost gauge to read manifold boost pressure or you’ve no clue what boost you have as the OE dash gauge reads the pressure before the carb.
· Larger than OE intercooler with alloy welded on end tanks and generally front mounted.
· Different camshaft profile, a favourite is the 285 @ 110°.
· Stronger clutch, normally the Valeo Volvo 480T. (Soft pedal conversion will extend clutch cable life)
· Firmer engine mounts to check the extra engine movement.
· Normally silicone boost hoses and new OE or silicone water hoses as old OE items tend to split. For reliability this applies even if you’re keeping standard power.
· Old pressure gauge to show you the reading at the inlet to the turbo.
· Adjustable bracket for top dead centre sensor to allow timing to be backed off a few degrees.
· Bottom pulley from a Campus engine; it’s smaller diameter turns the alternator / water pump slower and doesn’t throw off the belt on sudden lowering of high engine rpm.
· For long term turbo reliability, not noise, a double piston dump valve, possibly re-circulating for no noise at all. Double piston as they keep the inlet pressure up when off boost giving more responsive get up and go.

To give you some idea as to how tuneable the GT Turbo is, the RTOC hold an annual Drag event every year at Santa Pod and the current ¼ Mile record holder, Glenn Robson, ran an amazing 11.2 second quarter mile in 2010 all be it with the addition of NOS.

[Ian S]

RTOC RENAULT 5 GT TURBO BUYING GUIDE

This month the buying guide is on that cult Hot Hatch the Renault 5 GT Turbo. Back in the late 80’s & early 90’s these cars were many young man’s dream and were slugging it out with Peugeot 205 & VW Golf GTI’s around every ring road & leisure centre car park. There have been many buying guides for these cars over the years, giving differing recommendations on what’s right & wrong. However this time Performance French Cars have created a buying guide in conjunction with the Renault Turbo Owners Club (www.rtoc.org) to ensure that you are provided with the most accurate and comprehensive guide so far.

Over the last 25 years the Renault 5 GT Turbo has maintained it’sappeal to many car enthusiasts from those continue to compete and win in various racing series to those who want a small fast hatchback with great engine and chassis tuning potential to those who enjoy it as a styling icon for hot hatches with modification from the sensible and practical to the exaggerated extreme.

The inherent appeal of these cars is the lightweight nimbleness coupled with great driver feedback and it’s ability to put a huge smile on anyone’s face when the turbo comes on boost.

Many people remember the big wheels & excessive body kit scene of the nineties, epitomised by the Ali G film in 2002, but think that looks ridiculous with actual performance loss andthere has been a shift in restoring cars back to factory fresh original looking examples as illustrated by Big Steve’s concourse winning Raider pictured here.

HISTORY

The Renault 5 was launched in 1972 and spawned many performance versions from the Turbocharged Alpine (named Gordini in the UK), to the rear wheel drive wide bodied Turbo in 1980 that won the 1981 Monte Carlo rally, the Turbo II in 1983 and the Maxi in 1985 of which only 20 were made. In total only 5007 T1, T2 and Maxi were made.

The second generation Supercinq (Super Five) was launched in 1985 and was styled by Marcello Gandini who had previously penned the Lamborghini Countach. The chassis was based on the Renault 9/11 models with McPherson strut front suspension and transverse engine and gearbox, but the Renault 5 styling trademarks were retained.

When the Supercinq was launched the GT Turbo was not offered for sale but was included in the brochure as the “Coupe” model. This Coupe model was described as being developed for racing only and not available for sale, but by 1986 the GT Turbo was launched with a price tag of £7,710. Producing 115bhp, it was fitted with a slightly different body kit to the one shown here.

In 1987 Renault made a number of small but significant changes and designated it the phase 2 model. Most obvious was the painted and smoothed body kit that reduced the car's drag coefficient from 0.36 to 0.35, different wheels and seat cloth, and a more comprehensive centre console. Under the bonnet were some improvements to address the Phase 1 hot starting problems; • an Anti Percolation Fan to cool the carburettor, and when the engine is off, to cool the turbo compressor and also intercooler when it’s thermostatically controlled diverter flap is open, • a water cooled turbo charger and re-routing of some of the cooling system pipes. An ignition map change increased the power by 5 BHP to 120 BHP. To prevent heat damage the electronic ignition unit was relocated from above the turbo to behind the bulkhead. In 1990/91 the throttle cable to the carburettor was re-routed, the steering column rubber UJ was replaced with a metal one, the door cards were given a corduroy cloth cover, additional sound proofing and a light were added to the boot. In late 1991 the 5 GT Turbo was discontinued making H plates the last available although there are a few J and K registered cars around, these just cars stored by Dealerships and sold at a later date. The special edition 'Raider' 5GTT is a phase two with just some colour changes and no extra power. There were no 1.7 litre 5GTTs. There is a comprehensive list of the differences between phase one and phase two at the RTOC website.

There are approximately 3500 GT Turbo’s still registered with the DVLA and with the newest cars now 20 years and as Renault discontinue parts they are becoming harder to source. However, due to the fanatical following and a number of specialists, there are few parts that are truly unobtainable.

Advice

When looking at a potential 5GTT to purchase, bear in mind the cost of buying for what seems like a bargain vs. the cost of making and keeping it road worthy.

Don't buy one unless you know what faults to look for or know someone who does as very often the car will need specialist work be it mechanical or cosmetic.

BODYWORK

The Supercinq was one of the first new Renaults in the 1980’s to be fully treated to a 5 stage anti corrosion process and they've lasted fairly well but there are a few common areas for rust to watch out for. As with all older cars it pays to get it on a ramp to have a good look underneath.

Main areas to check are the outer sills, hidden behind the plastic sill extensions, the inner sills and the front jacking points which are an MOT fail. Thankfully all of these parts are available from Renault or third party panel suppliers, budget up to £300 per side for a restoration repair as opposed to a much cheaper MOT repair which may have been done for a previous owner.

Common rusty areas are the front and rear bumper mounting points. As these are hidden by the bumpers and arches they can really only be seen with the bumpers removed. The RTOC has managed to source a number of repair panels which have been specially manufactured to replace corroded panels in these areas and they are available through their website.

Easy to see is around the bottom edge of the windscreen. The 5's bonded windscreen needs to be cut out of the car to be replaced and the removal process can cause scratches or damage to the paint underneath the bonding agent. Repair panels are no longer available from Renault leaving your only option a repair patch. You can check the condition of this area by running you hand under the lower windscreen area from within the scuttle area. There are two small drainage holes at each lower corner of the screen where corrosion usually starts.

Also check the floor panel drainage plugs, where it folds up around the fuel tank, and the boot floor where it meets the rear arches. Check the tailgate around the glass.

The front doors can drop and become difficult to close if their hinges are not kept lubricated as they corrode and wear away. This can allow the bottom corner of the door to catch the sill and promote rust. It’s common now to have to fit new hinge pins and bushes on the newer version doors or drill and fit specially made shims, not available as a spare part, on the older versions.

INTERIOR

The interior of the car is comfortable and ergonomic. GT Turbos were fitted with a black vinyl covered dashboard instead of the standard hard grey plastic. In general the whole interior is fairly hard wearing but the drivers seat outer side bolster foam breaks down. New bolsters are still available from Renault at a cost of around £80 but cheaper replacements are available on the internet and second hand.

If the front seats rock excessively on their mountings check the two pivot bolts that couple them at the front to their sub frames as they come lose and need tightening from time to time. Otherwise it can mean having new DIY bushes welded in.

Original gear knobs are no-longer available from Renault and command a premium price.

The electric windows are known for being slow, this is caused by motors with old dried out grease & perished rubber guides. Some time spent cleaning & re-greasing the mechanism can vastly improve the situation. The central locking motors are available cheaply second hand.

Sometimes the cause for slow windows and central locks is simply corroded electrical connectors. These fail to pass adequate current to operate the motors and replacement for new is required as cleaning has little or no effect.

Check the carpet checked for dampness as water can leak in through a rusting scuttle panel under the battery tray, around the windscreen if it’s come away from the bonding or rusted through, around the rear side windows and from under the doors cards if their inner mastic seal has not been re-applied. It can also track in via the door speaker baskets.

Coolant can leak out of the heater matrix. To replace this, the dashboard may have to come out and this was listed by Renault as a 10 hour job.

If the orange dial faces of the instrument panel are faded they can be changed for new replicas that the RTOC have had made and are available from their shop.

There are no air bags and no collision seat belt tighteners.

There is no air conditioning except for a 5GTT variant available only in Japan.

No sunroofs were fitted by Renault. They were all fitted by the dealership network after taking delivery of the cars. Some dealers gave the customer making the original purchase a selection from a couple of versions. They can leak and drip water into the car and onto the front seats and at least one version has no available replacement parts.

WHEELS & TYRES

The 5 GT Turbo was supplied with 5.5J 13 inch Speedline alloy wheels and specifically manufactured 195 55/13 Michelin MXV Tyres. This custom sized tyre is now only supplied by Uniroyal in restricted numbers so some people fit 185/60 sized tyres instead which can degrade handling and does not give the same look to the car.

Many people fit 15” wheels, often from a Clio or with similar offset of about -35mm, and 195/45/15 tyres, which are about 10mm more in overall diameter to the originals, or fit less expensive 195/50 tyres. 15" wheels and lower profile tyres can sharpen the steering, increases the turn in bite and general grip for better braking and reduced wheel spin. They do make the ride 'bumpier'.

Whilst the radius with 195 45 15 is only about 5mm more than with the original wheels, height at the front from hub to the road is 10mm more due to less tyre squash than the original. It's 5mm higher at the rear. Lowering is in normally done just to get down the original ground clearance.

15" wheels also allow the fitting of bigger brake discs.

BRAKES

Have any of you compared braided lines to NEW OE rubber lines? We all know braided are better than old OE rubber, but so it new OE rubber.

The standard brake set up uses single pot Girling callipers and 238mm vented disks and are quite adequate for both standard and mildly increased power outputs. The rear brakes use solid discs with Bendix callipers that can be found on some Citroens and Peugeots of similar age to to the 5GTT and are moderated, depending upon the passenger load, by a compensation valve which is positioned in front of the rear axle. The hand brake works on the rear discs through the same pads as the foot brake. To change it's cable usually requires the removal of both rear callipers. There is an adjuster under the car to the correct handbrake lever height.

Ideally, check before buying that the discs are not rusted over and the front discs vents are not occluded by rust, the pistons and guides in all four callipers are free and the bleed nipples are not snapped off. Check the rear callipers pad retaining bracket is moving and not seized by rust or the pads don't press on the discs which rust over. Check that the spring tensioned compensation valve is free to move. This can seize causing insufficient rear braking but often can be freed with the help of some Plus-Gas.

If the seller can't demonstrate the recent age of the brake fluid it should be replaced as it can cause brake fade and the water in it can corrode parts such as the master cylinder.

Check the flexible brake lines for damage and age. Old original rubber lines should be renewed as they bulge under braking and can give a very soft pedal feel and not immediate enough braking. Use either new rubber lines or steel over braided PTFE lines.

Components are relatively low cost except for the brake servo unit at around £250 and the proportioning valve at £130.

With 15” and larger wheels, it's popular to fit larger diameter 285mm front discs together with calliper extender brackets. You won’t need to worry about fitting better callipers.

Big front discs are fitted for several reasons, for show, for less pedal pressure, for better for cooling but it’s not realistically possible to fit larger rear discs and this can lead to an imbalance of braking with too little from the rear tyres and poorer stopping. This is due to the extra leverage from extra diameter front discs leading to less pedal effort to lock the front wheels so the rears are simply doing proportionally less unless the rear compensator is turned on further by adjusting the rod toward the front of the car.

Don’t let larger front discs put you off even though many consider them unnecessary.

[Ian S]

STEERING

There is no power assisted steering in the 5GTT although some other models do have it. This can make it hard work to park this car.

Is there play in the steering of a car you are viewing? There could be several causes. If the steering wheel has lateral or longitudinal play that would probably be the two ball bearing bushes in the upper column.

On pre H reg 5 GTT’s there was a rubber lined universal joint at the bottom of the steering column which wears out causing excessive play in the steering but it's fairly quick and easy to change.

If the steering wheel is rubbing on the fascia then it's been re-fitted too low but it's easy to adjust back to it's correct height. This can also cause the steering lock to jam on and not be released by the ignition key.

Steering racks are generally OK but can have play in the rack and pinion which can often be can be removed by adjusting the rack damping plunger; this requires rack removal.

The track rod ends can wear at a faster rate if hard springs, shocks and lower profile tyres are fitted.

SUSPENSION

When I got my 5GTT in 1992 at 54,000 miles the shocks were possibly needing replacing. The cornering was rubbish compared to all the previous cars I’d driven. Have any of you compared new OE to old OE to see if that sharpens up the handling? Or was the OE actually just rubbish? Gripping, rolling, slipping, stepping out, unrolling: repeat: repeat: repeat. Maybe those balloon tyres didn't help, probably there for comfort to ease the hard bump setting?

The supercinq was a big advance compared to the old R5. At the front, McPherson struts with an anti roll bar. At the rear, trailing arms with torsion bars and anti roll bars.

Many people felt the original suspension from Renault was not very good as when cornering the car tended to skip sideways on the very soft walled tyres with one end then the other, then one end, then the other gripping, rolling then stepping out, often with the rear rolling and skewing excessively then pulling the front. The car was easily and excessively unsettled by minor bumps and hollows. Renault used soft springs and a hard bump setting on the shock absorbers. This altogether, despite the soft tyres smoothing micro bumps during motorway cruising, gave a both hard ride and made for a difficult and unpleasant drive.

Most of the cars on the market will have been fitted with some form of non original suspension and will have been lowered. Check for cut down standard front springs, leaking shocks, and play in outer ball joints. Also check for play in front wheel bearings as with harder springs and lower profile tyres they can need replacement is as little as 12,000 miles. Any knocks or rattles on a test drive should be investigated and used as a negotiating point over price.

Often the front strut top mounts rubber 'doughnuts' squash and cause play both in the strut, which moves around, and in the steering when driving and can cause the rear of the car to sway side to side at speed making it difficult to steer in a straight line. If left uncorrected the metal strut top mounting plates can wear away and are longer available new. Refurbished parts are still available.

Wishbone and anti roll bar bushes are also prone to wear on hard driven cars and make the steering imprecise especially at speed and during braking. However original and polyurethane replacements are available.

The car responds well to the fitting of a front strut brace as it will steady the car during hard cornering, view this as a bonus if included in the sale.

Camber adjusting bolts are sometimes fitted to the front to try and provide more grip for cornering by adding more negative camber but can cause inner edge tyre wear. So on any lowered car check that there is not excessive negative camber. 1 – 1.5 degrees negative camber is normal.

If the inner edge is worn this can also be caused by incorrect tracking.

A well maintained car will have had a quality spring and damper combination fitted by now. The most popular is a Koni ‘yellow’ shock absorber and spring kit which retails for around £400. Different to what one might expect, the Koni kit gives a softer ride than the original equipment even though it eliminates the ‘boaty’ handling and replaces it with taught and driveability.

The supplied springs are often just for lowering but using at least 175lb per inch springs will dramatically improve the turn in and general cornering and 250 lb/inch is a lot better again although the ride is somewhat bumpier but possibly still less harsh than the OE. Some people are using 300lb/inch with re-valved Konis.

The front suspension geometry is designed to keep both front tyres flatter to the road surface while the car rolls; the outer wheel gains more camber and the inner wheel loses some. Lowering the front can adversely affect this, reducing the grip and upsetting the handling. Fitting harder springs might reduce this by reducing the roll.

If when you press down on the car wings to check the shock absorbers you find there is almost no movement, it could be the the car has been fitted with some very stiff 'coil over' shock absorbers. These can be too stiff for road use and can hurt your back and jar you internal organs. Owners fit them for appearance because they allow the ride height to be lowered further than can otherwise be done. Sometimes it's to have suspension that barely moves at all as some owners perceive this to confer a performance improvement for cornering of flat smooth roads. Whilst this can be the case with high quality shock absorbers that still do move over bumps, these low quality one simply make the ride unbearable and can also wear out quickly so you may have to budget for new shock absorbers.

Lowering the rear is accomplished by partially removing, turning and refitting the rear torsion bars. If you plan to make any changes to the offered cars ride height investigate when they were last removed as they commonly seize and require lots of work to free them up. You can quickly check condition by removing the black plastic cap on the end of the rear beam under the arch, any corrosion or a damaged thread into the torsion bar and you may have to replace the beam, lots of copper slip is a good sign.

It's very common for owners to lower the rear onto the bump stops of the shock absorbers as it's felt to improve the cornering on smooth roads. Apart from making the ride painfully hard at speed over bumps and bouncing the rear sideways, this quickly damages the rubber stops which can break away leading to shock absorber damage, leaking and the requirement to be replaced. Shorter shocks with more progressive bump stops are available.

Some people feel that with the small standard sized wheels the cars look as though they have too much arch clearance and like to lower the cars to improve the look; Steve’s car pictured here is lowered by 35mm at the front.

ENGINE

The Renault 5 GT Turbo uses a heavily modified four cylinder, eight-valve “Cléon” (or C Series) 1397cc engine. The unit is a Pushrod OHV design that can trace it’s roots back to 1962. To cope with the rigours of turbo charging, it was fitted with hardened valve seats, the compression ratio lowered 7.9:1 and heavy duty pistons with a 13mm crown thickness. The engine uses wet liners in a cast iron block meaning that the entire piston & liner assemblies can be changed without removing the engine from the car. The C1J engine is what gives this car much of its character.

The phase one 5GTT has the electronic ignition mounted over the turbo. This is not good as the heat damages it and it's likely to either be faulty or about to become so causing the idle speed to continuously varies up and down and detonation can occur on less than full boost. In later models Renault moved it to behind the bulkhead.

A common misconception is that the engine and particularly the head gasket is unreliable. In reality quite the opposite is true if a few golden rules are followed. This bad press came about because owners in the 90s were increasing boost pressure without adjusting the fuelling within the carburettor resulting in detonation and H/G failure. An engine that has had vaguely regular servicing and maintains a good oil pressure will easily survive to 150k miles before rings, main bearings or valve guides need replacing, even when run well above standard boost. Many RTOC owners run 20 year old, totally standard engines up to 180 BHP for every day use without any problems and 200+ BHP is also easily achieved with mild cams and even bigger turbos. The key to reliability is in accurate fuel set-up, and using super unleaded to prevent detonation.

When buying check what boost is being used and ask lots of questions about the fuelling set up, a knowledgeable owners club members car will have had lots of attention in this area. A wide band lambda sensor and gauge is essential for any car running a bar of boost or more and should not put you off. Once set up you can remove this for an original look but remember to check fuelling regularly.

Always view the car started from cold. Make sure it idles correctly on the choke with very little smoke, white condensation is fine. Once warm ensure the fan starts and stops automatically without the temperature going over the third notch on the dashboard gauge. Then take it for a drive and check for black or blue smoke on boost or when backing off the throttle. Ensure you drive for at least 15 minutes and on return check to see if the owner lets it idle to let the turbo spin down before turning it off – a very good sign. Whilst still fairly hot, remove the oil filler cap and oil dip stick to check for 'mayonnaise' and check that the coolant level in the header tank has not dropped too low and there is no 'mayonnaise' in the coolant; that's a bad sign! If the anti-percolation fan doesn’t start automatically do not panic, they are often temperamental and require regular attention to the loom, heat sensors and fan unit. Squealing or leaking from behind the water pump pulley means it needs to be replaced; replacements are cheap and easy to fit.

If the original anti percolation fan is worn and will be nosey when spinning. Very early ones were not fused and sometimes caught fire if they seized. Renault issued a recall and all should now be fused near to the fan. Often they are removed but they do help to prevent a hot engine stuttering when driving in slow moving traffic. A much quieter yet more powerful fan is one from a Renault Safrane.

Another popular modification is to simplify the breather system as with higher boost oil often makes it past the oil swirl pot and blows out from the various places, such as a dump valve, of becomes smoke from the exhaust. some people leave all the pipes in place except the one into the turbo and instead take that to a catch tank, preferably fitted with an oil drain back to the sump. Others remove the whole lot and just use a pipe into a bottle. If the engine develops a fault and a lot crank case pressure occurs, without the catch tank oil drain, unless it 4 litres in volume, it will overflow and the engine might then seize.

Check all the coolant and breather pipes for damage, they can rub together and burst if not retained in the OE clips or have been cable tied together. Beige stains can be a sign of coolant leakage.

Check the two bleed nipples are in good order, brass replacements are available for the plastic type plugs and are a wise investment. Silicone replacement hoses are another popular upgrade, however check for cheap Chinese copies which are inferior, SFS and Samco have a good reputation.

CARBURETTOR

To control the fuelling a Solex 32DIS single choke Carburettor is used rather than fuel injection. This is positively prehistoric compared to today’s modern cars which have sensors everywhere. However this simple set up means that the cars are easy and cheap to tune. Thanks to the advance in wideband lambda sensor technology it is easy to re-jet the carburettor to deliver the correct amount of fuel for an increase in boost pressure.

Group A and Group N are racing classes and genuine racing parts are extremely rare. The so called Group A Carb as sold by tuners is best avoided as they are often just a bored out venturi and some over sized jets which fuel excessively rich, especially at part throttle. Look for a car with a recently serviced carburettor that has had lots of attention paid to the set up.

Re-jetting of the Carb requires an detailed knowledge of which parts to drill out and by how much, otherwise you will ruin your carburettor, over fuel the engine and risk premature wear of the turbos bearings through petrol in the oil. A number of RTOC members have become very skilled in setting up the Carb’s and can tune them to give either big power or much improved fuel consumption, many of whom only charge a cup of tea for their services.

A common problem with the 5GTT is poor idling, this is usually down to a blocked idle jet, however it is possible for the base of the Carb to be warped and the throttle spindle seals to be ovalised and leaking air. Replacement carburettors are all 20 years old now and will require a minimum of a new seal and gasket kit available for approx £30. RTOC sell a comprehensive re-build kit through their on-line shop and have detailed re-build guides on the website.

TURBOCHARGER

The GTT was originally fitted with a Garrett T2 Turbo and runs 7 psi of boost. This offers a good mix of power and low turbo lag. It is possible to increase the boost pressure of the T2 Turbo up to an absolute maximum of 14 psi at the manifold with standard carb and cam.

If the car your viewing has increased boost pressure then it should be fitted with an extra pressure gauge to sense manifold pressure. This doesn't mean the car has been abused but that the owner has taken care to monitor the pressure level. Another good sign is an oil pressure gauge that senses the pressure just before the turbo as turbos are particularly sensitive to low oil pressure which can result in very fast bearing wear. A turbo is also sensitive to poor oil quality and to the engine being switched off immediately after hard acceleration or high speed and can jam due to the oil in it burning and setting hard in it's bearings. This results no boost pressure.

Continual grey smelly smoke from the exhaust often means they turbo oil seals are worn and will need to be replaced. It can but does not neccessarily mean new turbo as there are several companies that can refurbish and rebalance for maybe £350 but the fee varies with what needs to be done.

Many cars are now fitted with a larger turbo, T25 or T28, enabling an increase in boost pressure up to 20+ psi. A favourite is a Tomcat specification turbo, not an actual Tomcat turbo from an old Rover. These larger turbos have a larger lag which means they are not so usable around town but the higher top end power means they are great for overtaking on country lanes and main roads.

Turbo roller bearings are hardy and give maybe 200rpm less lag, but are expensive. VNT turbos are becoming popular as they spool much more quickly but still offer the large turbo benefits of lower back pressure and higher boost.

Dump valves are fitted by car manufacturers to increase the longevity of the turbo by preventing a high pressure spike after the turbo when the throttle is suddenly closed. They are fitted by turbo car enthusiasts often just to make a loud noise as some designs vent to atmosphere rather than re-circulating the pressurised air back into the turbo inlet. They can wear and leak and result in low or no boost. Double piston dump valves are less common, more expensive but better as they keep some boost pressure in the pipes giving a faster initial response to opening the throttle. The 5GTT did not have a dump valve from new.

The boost pressure is controlled by air pressure pushing a diaphragm in a metal can attached to the turbo which pushes open a metal flap in the turbo known as a wastegate. This can is known as the actuator and the original ones have a soft spring inside which is not much use with higher boost as it's not enough to hold the flap fully shut so the boost is slower to build. Worse still if a bleed valve is fitted to increase boost by bleeding off pressure to the diaphragm instead of the metal rod being wound on further to increase spring pressure. The correct fix is to fit a better actuator with a removable spring allowing one to be chosen to match the boost pressure you want. A favourite is the T3 style actuator with a spring rating designated -12.

Renault included a method of controlling the turbo wastegate actuator that many people remove. It's know as the "Cup mod" as it was the method used in the 5GTT Cup racing series. It removes some rubber pipes from the engine bay and results in a sharper boost response which many owners like.

EXHAUST

There are likely to be a variety of tailpipes emerging from under the rear bumper, or sometimes from the left side in front of the rear wheel. Some people think the look of the tail pipe is all that matters but the rest of the system is crucial to performance. Originally there was a tiny tailpipe and a quiet two silencer system with a sprung flexible coupling near the front joining to a thick walled pipe with narrow a bore going up to the turbo. The flexible coupling was fixed in place by a plate and a bar coupled to the engine block and often owners have not refitted these. No catalytic converter is required in these pre '91 cars.

There is a good deal of performance to be had from a well designed free flowing replacement system that does not contain a restrictor or a narrow bore silencer, apparent as a welcome increase in torque and reduction in turbo spool up time as a result of the lower back pressure after the turbo.

Also original equipment is a boost compensation system which senses the pressure rise in the original exhaust after the turbo and applies air pressure to the front part of the turbo actuator, closing the wastegate a bit and raising the peak boost pressure about 1psi. This does not function with a free flowing exhaust so the system of pipes that constitute it are often removed and certain holes plugged.

There are many replacement exhaust but the best for performance are the 2 1/4" or 2 1/2" full systems that are from the turbo backwards. These are usually stainless so will last well. If the seller is talking about a big bore exhaust make completely sure they are not just referring to the diameter of the tail pipe alone as this is meaningless apart from a small change in the noise.

It's not that unlikely now that the car will be fitted with a side exit exhaust. These are quite a bit louder both outside and inside the car. A good side exit may yield a small performance increase over a very good rear exit system but possibly only at very high boost and power levels. They are less expensive to buy and fit than a rear exit system and do pass the MOT.

COOLING SYSTEM

Any increase in the boost pressure/performance of the car puts more load into the cooling system which unless it is properly maintained will lead to the car overheating and again possible head gasket issues. The RTOC state that the standard cooling system is more than up to the job as long as it is properly maintained. If the car seems to be running too hot it is probably a partially occluded radiator or a build up of silt within the system. Once the cooling system is fully thoroughly flushed out, and the water pump checked for a good flow rate most overheating problems will disappear otherwise the radiator will probably need to be replaced. Some replacement radiators made from copper were know to leak. For flushing only use water as some engine flushes have been known to block turbocharger waterways. The cooling fan should cut in as the gauge reaches the 3rd of 4 marks unless a low temperature fan switch is fitted where it will be about 1/2 a mark lower.

Some people remove the thermostat in the top radiator hose near the water pump in a vain attempt to help car run cooler, however this means the engine does not warm up fast enough and can cause cavitation within the water pump and erosion within the cylinder head.It is better to use a low temperature radiator fan switch. Some people like to drill a 4mm hole in the top of the thermostat to aid coolant system bleeding.

If there is white powder in the exhaust tail pipe this can mean an over heating engine possibly caused by blocked radiator.

There is an oil cooler built into the radiator to prevent the oil from over heating.

[Ian S]

CLUTCH

The clutch on the 5 GTT is known for being quite stiff to actuate but should disengage before the pedal reaches the carpet. If you find yourself having to push the pedal almost through the floor of the car to disengage the clutch there is a problem. This first thing to do it to check the self adjusting mechanism is not jammed but moving freely. If it is jammed then free it by pulling it toward the drivers seat, it is only a simple ratchet situated just above the pedal.

Another cause might be a stretched clutch cable which could snap at any moment so should be replaced ASAP before you are left stranded. However if the release mechanism is fully functional it will take up the slack.

OE cables are much higher quality than pattern parts which frequently snap, particularly when routed incorrectly.

Early on Renault changed the clutch pedal design to what is often known as the ‘White’ pedal due to it having white plastic instead of black. This should have been fitted in the recall but many weren’t. This more or less eliminated the problem of the clutch cable snapping every 6000 miles or so.

There are two original clutch cables, one for the black pedal and one for the white. They are slightly different lengths. However it is difficult to tell which you have fitted, and even with the clutch centre plate worn to the rivets the pedal will be at the correct height if the self adjust is working properly.

For much above standard torque, the RTOC recommend the Valeo Volvo 480Turbo three piece clutch kit, it has sufficient torque capacity for all but the most powerful GT Turbos and is relatively cheap. When you are changing the clutch a sensible modification is to convert to the longer release lever and new pivot which will give you a softer clutch pedal with longer bite point and is much easier to use to feed in the power, especially on a wet road, and it also reduces the risk of snapped cables with this harder sprung clutch.

If the pedal is very hard to press and there is a sudden fierce bite this means a clutch such as the one mentioned above has been fitted but without the longer release arm. It not possibly to fit the arm without parting the engine and gearbox but some owners have welded an extension onto their existing arm.

The Group N clutch that you may have seen vendors selling is not an expensive special part but a standard clutch from another car. The Group A clutch will be a more expensive item and there are a few suitable parts around to make up something if the Valeo Volvo clutch torque capacity is not enough, e.g., if you’re making 230ft lbs, then the Valeo Volvo pressure plate can be used with a cerametallic paddle centre plate from AP racing or Helix, however these can cause judder on take up, badly wear the flywheel and not last long on a road car.

GEARBOX

The GT turbo gearbox is a JB series box. Phase 1's were numbered 014 and the Phase 2's were 032 and are fairly robust. They utilise an electronic Speedo pickup which can be prone to connection problems and means that the speedometer does not run or record the mileage. You should check that the gearbox shifts smoothly and that you can not hear any strange rumbling or whining during a test drive. A symptom of a tired gearbox is the fact that the car jumps out of 2nd, 3rd or 5th gear particularly when backing off the throttle which means the unit is worn, or the main retaining nut on the lay shaft is lose.If this is the case you will probably need a replacement gearbox or a rebuild. Don’t be fobbed off by the seller telling you that “they all do that” and all it needs is a change of the engine mounts or adjustment of the gear linkage rod.

Another problem which can happen to the JB series gearbox is that a large circlip on the passenger side of the unit can snap and the differential just spins leaving you without any drive. Thankfully it’s relatively easy to change and, as they fit all JB series gearboxes, are cheap to buy direct from Renault.

The 5GTT uses a JB3 and has the longest gears. Whilst it’s fine for plenty more then the original 120ft lbs, it can be a limiting factor for higher torque 5GTT’s. The bearings can fail after some time in moderately high powered cars. The JC5 box from a Clio has different bearings but there are conflicting reports as to their longevity when compared to the JB3. If torque is particularly high and traction is sufficient then the gears can instantly break as they are made from brittle cast iron. 1st gear is especially poor and the crown wheel can brake up and punch its way out of the casing. Its not uncommon to have the diff pop out of place if the retaining circlip becomes unseated. Sometimes tack welding this into place can fix it. Upgrading to a JC5 casing and bolt-in diff would be better.

JB5 is a 5 speed gearbox found on the NA's 5’s. It has a shorter case (bell housing to end cap) and narrower gears; and is much less strong than a JB3. JC5 is the Williams/172/182 unit and is the preferred gearbox, ratio's aside, because they nearly all come with a 4.07 final drive, which is a bit short for a typical GTT revving to 6500rpm. Put the final drive from the GTT's JB3 into a JC5 and you're onto a winner.

POWER/TUNING

The Phase 2 5 GT Turbo left the factory with 120 BHP which does not seem very high now compared to many modern cars, however as the car is very light at 830kg the power to weight ratio is quite high and a moderate increase in power can give impressive results. Many people strive to reach 200 BHP and to achieve this, the RTOC recommend the following modifications:

· Correctly re-Jetted standard venturi’d carburettor set for 20 to 25psi of boost.
· Free flowing exhaust with larger bore from the turbo back all the way through to the tail pipe. Not one with a restrictor or narrow baffle.
· T25 or T28 Turbo set to 20 to 25 psi; a favourite is the ‘Tomcat Spec’ not the actual Tomcat turbo. The larger the turbo the more power and the more lag.
· Stronger actuator, preferably the T3 type with a -12 spring.
· Actuator piping changed to the ‘Cup Racing Series’ Modification.
· Delete the rest of the boost compensation mechanism as it has no effect once a decent low back pressure exhaust is fitted.
· Boost gauge to read manifold boost pressure or you’ve no clue what boost you have as the OE dash gauge reads the pressure before the carb.
· Larger than OE intercooler with alloy welded on end tanks and generally front mounted.
· Different camshaft profile, a favourite is the 285 @ 110°.
· Stronger clutch, normally the Valeo Volvo 480T, with 'soft pedal' conversion.
· Firmer engine mounts to check the extra engine movement.
· Normally silicone boost hoses and new OE or silicone water hoses as old OE items tend to split. For reliability this applies even if you’re keeping standard power.
· Oil pressure gauge to show you the reading at the inlet to the turbo.
· Adjustable bracket for top dead centre sensor to allow timing to be backed off a few degrees.
· Bottom pulley from a Campus engine; it’s smaller diameter turns the alternator / water pump slower and doesn’t throw off the belt on sudden lowering of high engine rpm.
· For long term turbo reliability, not noise, a double piston dump valve, possibly re-circulating for no noise at all. Double piston as they keep the inlet pressure up when off boost giving more responsive get up and go.
• A crankcase breather oil catch tank will probably be required.
• Taking the inlet air from a cold place near the font of the engine bay through a decent flowing filter, possibly trumpeted.
• For reliability, new valve springs, possibly longer, harder and in lowered seats to match the taller cam. Possibly new collets. Possibly rocker faces over the valve stems reground to remove the edges worn by the standard cam. No need for valve seats, throats, ports, matching manifold at this power level, it will yield little power for the expense.
• NB: Modify at your own risk! This is not a detailed list, just basic guide. It's not the RTOCs fault if your engine fails after only a few minutes because you didn't understand what to do and didn't ask the right people the right questions!

To give you some idea as to how tuneable the GT Turbo is, the RTOC hold an annual Drag racing event every year at Santa Pod and the current ¼ Mile record holder, Glenn Robson, ran an amazing 11.2 second quarter mile in 2010.

[Ian S]

Suggestions:

- Links to further information (such as the ph1/2 differences list and other information we have on the site that's available to non-members).

- Pictures (always say a thousand words)

- Price range advice

- Debunk myths section

- Colour options? UK vs Europe?

- Odd/interesting facts section - special editions, museum locations, annual Renault events, popularity of GTT's in places like Netherlands etc etc?

Trev if you or anyone else were able to make something from these suggestion I might be able to fit them in. I'm running out of steam for this now.

Do we publish the tuning section or should that be saved for members like Alistair suggest?