which cam.?

[raj]

..

[SCHWARTZ]

all standard will be fine if the fueling is spot on and charge temps are good. May be worth retarding the ignition slightly also.

[JRP]

all standard will be fine if the fueling is spot on and charge temps are good. May be worth retarding the ignition slightly also.

A standard cam on a full t25 would be interesting :scratch:

[Spooky]

The standard cam is very good, don't mock it!

[Andrew Cooke]

The standard cam is very good, don't mock it!

which standard cam?

[JRP]

The standard cam is very good, don't mock it!

Mockity mock mock mock :p

[JRP]

which standard cam?

oh i forget about that small detail... is there alot of difference andrew?

[Spooky]

which standard cam?

I was referring to the Renault 5 GT Turbo camshaft Andrew Cooke :D

[Spooky]

Mockity mock mock mock :p

Cock :laugh:

[JRP]

Cock :laugh:

Huge one :laugh:

[JRP]

how does the bb300 cam compare to the piper285.?

I can sell you one if you want to find out ;)

[Andrew Cooke]

I was referring to the Renault 5 GT Turbo camshaft Andrew Cooke :D

Which Renault 5 GT Turbo camshaft Sukhi Toor?

[Spooky]

Which Renault 5 GT Turbo camshaft Sukhi Toor?

You know what, I'll hang my gloves up now...as I know how excited you get when we start getting all historical and start nattering about specifications and part numbers :wasntme:

[Brigsy]

Piper 285 would work well with a full t25.

[Brigsy]

No idea really, i would just fit a 285 and be done with a t25. Would keep the pistons/liners/rods standard too no need to go forged at that power level.

[Danboi2]

wheres the cheapest place for a piper 285 cam?

[Sparkie]

piper?

[Brigsy]

Piper done me a fairly good deal when i bought mine, cant remember the exact price now.

As for forged pistons and rods i wouldnt know how far stock items will go? all depends how safe your tune is i guess & what the engine is used for i.e, drag/street or track?

[Ian S]

Hi fellas, can you read this and comment please; corrections and suggestions please.

Before it's sent off to the magazine.

I'm posting it here as it's being ignored in other places.

Thanks.

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!

[David H]

Is a "full T25" really that bad with the standard cam? This is the setup I have and I've been thinking it was a bit pony (small power band) but because it's been such a long time since I drove the car I can't remember what to expect.

I have a CatCams 5500327 (with springs) ready to go in because I guessed it'd be a better match, I've just not got around to fitting it.