Clio turbo boost issues

[SP33DY]

As some know I have a turbo'd clio ever since it's was converted I've suffered boost drop off from 22psi to 12psi.

I done a bit digging around and everything seemed to point to the t2 7psi actuator that I was using in conjunction with a multi boost controller. The theory was that the spring was to weak to hold the wastegate shut whilst I was trying to force enough exhaust gasses through the turbine to hit 22psi

So i replaced it yesterday with a forge adjustable actuator fitted with there 10-15psi spring, I bypassed the boost controller and manually set the actuator to peak at 14.5 psi (even this drops off to 10psi at 6500rpm though)

When I reconnected the boost controller and set the gain to run 22 psi I was pissed to see the boost was still dropping off to 13psi.

Has any one got any pointers on where to look next as all my hoses are connected correctly and leak free.

Cheers

Steve

[Bigfoot]

You got any pictures of your engine bay?

[SP33DY]

You got any pictures of your engine bay?

Nope not yet.

I supose I could whip the inlet manifold off, check the plugs are nice and tight, then apply some sealant round the inlet manifold joins.

Any ideas on whats the best sealant to use for this?

And also whats the simplest way (if there is a simple way) to pressure test the manifold?

Cheers

[Mart]

If it were inlet manifold/post t.body related, the engine would struggle to idle.

I think you'd hear the boost leaking away if you're losing ~10psi, as that's quite a fair drop.

Might be worth checking the exhaust manifold & gasket, and likewise, also check the wastegate itself is fully sealing/surrounding area isn't badly cracked & leaking exhaust gases through.

Failing that, could still be the actuator (assuming you've pre-loaded it correctly), as Forge's actuators have been know to lack durability.

[Ashy]

Any ideas on whats the best sealant to use for this?

I use the same stuff as Reno reconmend for the cam cover!! mine leaked like fcuk before i did it too! Although not as much as 10psi!!

I'm wondering if your turbo is man enough to keep up with the demands of the engine? maybe it just can't keep up?

[Slim]

dont think its the manifolds... im pretty sure you would here it otherwise...

thats alot of boost to go missing... i reckon its a boost leak somewhere in the boost circuit... to make sure.. take off everything.. check the pipe and put them back on again but take your time!! use new clips where needed to..

boost leaks can be very annoying!!

[Slim]

what is the turbo's history??

[SP33DY]

Well rather than chasing a phantom fault around, I decided to phone ktec and ask what pressure there high boost 300bhp turbo conversion was running.

It runs 1bar but drops off to 12psi higher in the rev range, so looks like its a good old fashioned case of the turbo being too small.

Now this presents me with a massive decision.

Do I

a) get a bigger turbo? which means moving to an external wastegate due to the space the turbo sits in being to small for a larger turbo and an internal wastegate/actuator assembly. As well as having to buy the turbo and the ext wastegate I'd also have to have my manifold and downpipe modified to fit.

or

b) put it all up for sale on cliosport and get a high boost supercharger fitted?


Cost wise they wil be about the same and I'd be looking at 350+

[SP33DY]

what is the turbo's history??

The turbo is a gt2560r with a t3 comp housing and was brand new when I got it, it's done about 5k now but is in mint condition

[Ashy]

Easiest way to check for boost leaks is take the airfilter hose off the front of the turbo and block the inlet with a can of pop or similar. Then get your compressor and plug it into a port on the plenum, servo outlet or FPR senor port etc. Set the compressor to say 10psi and pump up the boost system. check your boost gauge is reading the same as the compressor if it is then great, if not then you have a problem but at least it'll be easy to find becasue it'll be hissing!

[Ashy]

[quote=SP33DY;112994]

It runs 1bar but drops off to 12psi higher in the rev range, so looks like its a good old fashioned case of the turbo being too small.
quote]


Ahhhh, nightmare... I thought this might be the case as you see the same boost drop as me and matt (ringworm) although ours isn't peaking as high. We've both put ours down to size of the blower.

Its a good job you've got plenty of cash

[Slim]

well... it could be a wastegate issue... but i doubt it... normally a boost leak somewhere.. js do as he says with the compressor

[SP33DY]

Easiest way to check for boost leaks is take the airfilter hose off the front of the turbo and block the inlet with a can of pop or similar. Then get your compressor and plug it into a port on the plenum, servo outlet or FPR senor port etc. Set the compressor to say 10psi and pump up the boost system. check your boost gauge is reading the same as the compressor if it is then great, if not then you have a problem but at least it'll be easy to find becasue it'll be hissing!

Not a bad idea but I don't have a compressor.

[Mart]

Do I

a) ...

or

b) ...

Or c), try some of the ideas mentioned before wasting your cash.

[Slim]

use a foot pump then

or go to a petrol station where they fill up air to the tyres..

[Mart]

Easier way to check for boost leaks, that'll cost you nothing - Simply occlude the turbo inlet pipe, start the engine, and see if it runs - If it does, ok, you have a boost leak. If it doesn't/it stalls, you don't have a boost leak, and it's exhaust manifold/turbo related.

[SP33DY]

Ahhhh, nightmare... I thought this might be the case as you see the same boost drop as me and matt (ringworm) although ours isn't peaking as high. We've both put ours down to size of the blower.

Its a good job you've got plenty of cash

I wouldn't go as far as saying loads of cash, just an understanding girlfriend.

Obviously option c could be to stop obsessing with 300bhp and make do with what i've got.

[Andrew Cooke]

The turbo is a gt2560r with a t3 comp housing and was brand new when I got it, it's done about 5k now but is in mint condition

that compressor should be fine for a bit more than you're geting out of it. Turbine is on the small side, I'll bet you're still blowing the wastegate open (assuming it's not a big air leak).

Unless things have improved a lot, those forge wastegate springs are dreadful. You're better off with a decent Garrett actuator.

[SP33DY]

Right i've been and checked for airleaks using Marts method popped the induction filter off and shoved my hand over it with the engine running. Nearly lost my hand but it was an instant suction and engine stall.

Am going to let it cool down and adjust the actuator some more, basically all I did was adjust the bar untill it was about 5mm short of the wastegate pin, then struggled to pull it over it. I'll try and shorten it by a further 5mm nd see how it goes.

The only other thing I can possibly think off is the valve overlap when in the phased state, It's something I had the mapper briefly look at before but think I might look at it alot closer now, Scoffs disabled his with obvious good results.

Andrew the only reason I got a forge was I couldn't find a suitable actuator from anywhere, I'm tied to a T2 size actuator due to the space limitations of where the turbo sits, plus the actuator lugs are welded onto the T3 compressor housing which means its a non standard length, after looking everywhere the only place left was forge.

[dave j gtt]

oppps at what point did mart tell you to put your hand over the inlet of your turbo

[SP33DY]

oppps at what point did mart tell you to put your hand over the inlet of your turbo

He told me to stick my fingers in the compressor housing to try and stop the blades from spinning.

My induction filter sits about 60cm from my turbo so it was a safe approach.

[Mart]

Right i've been and checked for airleaks using Marts method popped the induction filter off and shoved my hand over it with the engine running. Nearly lost my hand but it was an instant suction and engine stall.

Ok, so that eliminates any leakage from turbo inlet to t.body. The fact you have a good idle (when you aren't occluding the inlet!) also now eliminates the t.body, inlet manifold, and inlet manifold gasket, so the problem is on the exhaust side of things; ie, gasket leaking, exhaust manifold cracked, turbo not upto the job, wastegate not sealing/area cracked, or still the actuator (pre-load incorrect, or simply not upto the job still).

[SP33DY]

Right i've just been out and tensioned the actuator some more, its preloaded about 10mm now took it out for a spin and 12.6psi was all she would give me. It took a team effort of me and my dad to get the bloody thing hooked back on.

So I pulled the vacuum pipe of the actuator and went back out again using my trusty right foot to try and regulate the boost in third, managed to maintain 20-22psi upto 5500rpm which was a bit hectic, so definatley think it's the actuator at fault.

Am going to leave it for tonight and pull the actuator off tomorrow and have a look at what colour spring has been provided.

[Rob@Backyardracing]

As you mentioned while your at it id deactivate the phaser, turbo cars dont like overlap, specaily if your a higher booster.. Log your mani/TIP pressure and temps with and without the phaser and report back, be interesting to see... Im sure scoff prob has messed about with this with results?

[Andrew Cooke]

Right i've just been out and tensioned the actuator some more, its preloaded about 10mm now took it out for a spin and 12.6psi was all she would give me. It took a team effort of me and my dad to get the bloody thing hooked back on.

So I pulled the vacuum pipe of the actuator and went back out again using my trusty right foot to try and regulate the boost in third, managed to maintain 20-22psi upto 5500rpm which was a bit hectic, so definatley think it's the actuator at fault.

Am going to leave it for tonight and pull the actuator off tomorrow and have a look at what colour spring has been provided.

if pulling the pipe off allows the boost up the actuator must be able to hold shut.

I think your boost controller may be the problem, do you need a smaller restrictor between the controller and the inlet. BTW, does your actuator pipe go on the engine side of the throttle body, or not?

[Ashy]

So I pulled the vacuum pipe of the actuator and went back out again using my trusty right foot to try and regulate the boost in third, managed to maintain 20-22psi upto 5500rpm which was a bit hectic, so definatley think it's the actuator at fault.

That doesn't make any sense? (to me anyway) I was under the impression you had a boost controller? I thought they worked as a 12v solenoid valve where by they just bleed off any boosted air until the car hits your pre-set boot level and they click over / stop bleeding and let the actuator see the boost pressure to open the wastegate at that pre-set level?

If thats true then it shouldn't make any difference running without a vac pipe or running with the controller? Unless the controller is set too low? Or my understanding of how a boost controller works is totaly wrong!

I thought your problem was that due to the small size of the back end on your turbo the exhasut gass pressure was forcing the wastegate open and causing the boost leak then?

Like Rob says maybe when you are running in the phased state and you have a lot of overlap maybe this is increasing the amount of pressure in the exhaust manifold, I don't have any problems on mine although im running less boost with a bigger actuator!

[SP33DY]

I don't think explained myself very well in the last post.

I fitted the actuator and to set it up bypassed the boost controller.

I preloaded it so that it peaks at 14.5 but it was dropping back off to 10. This was obviously better than the 7 psi previously fitted so I expected to see some form of gain.

I then re introduced the boost controller to the circuit and was disappointed to see it peaked at 22psi and dropped off to 13 psi.

After that I carried out Marts entertaining test, as well as taking the top mani off and checking the plugs.

Removed the boost controller and preloaded the actuator further it really was super stiff to fit and felt far too tight but I gave it a shot anyway. This is where a strange thing happend, rather than the boost being higher it had actually lowered it to the steadiest boost reading I've ever seen 12.6 psi.

Getting frustrated at this I pulled the vacuum pipe off, sealed it and took it for a spin
obviously I could only use part throttle to control the boost and but I was able to maintain 20ish psi up to 5500rpm (I was in third and heading into silly figures whilst trying to watch my inconvienently placed boost gauge/controller) this gave me hope that the turbo can maintain the boost, however this was only at part throttle and when using the boost controller, and applying wide open throttles it peaks at 22psi then heads south agin quickly.

Hope thats a better explanation

[Andrew Cooke]

Hope thats a better explanation

it is, and shows that it's a boost controller problem.

[SP33DY]

Do you think that the reason for the steady reading is the actuator is correctly tensioned for 12.6 psi?


--------------------------------------------
Ashy

the actuator will only hold what it'll hold. However your test with the vac pipe shows that the turbo is capable of making more boost as the wastegate is not being forced open by the exhaust gas pressure!! Therfore as Andy says if thats true then the problem lies with the controller as for some reason it is letting the boost pressure through to the actuator before you reach your set cracking pressure.

Sorry this should of been in here, i posted it in the wrong thread!!
---------------------------------------------

[SP33DY]

if pulling the pipe off allows the boost up the actuator must be able to hold shut.

I think your boost controller may be the problem, do you need a smaller restrictor between the controller and the inlet. BTW, does your actuator pipe go on the engine side of the throttle body, or not?

The pipe runs from an outlet on the comp housing.

The boost controller reading is taken from the inlet manifold.

[Andrew Cooke]

The pipe runs from an outlet on the comp housing.

The boost controller reading is taken from the inlet manifold.

for driveability the boost controller reading should be from the other side of the butterfly. It won't won't sort your problem, but it will drive better.

which boost controller are you using?

[SP33DY]

It's the gizzmo ms-ibc here

http://www.gizzmoelectronics.com/Product_MSIBC.html

Not sure which side of the manifold your suggesting Andrew but it's currently taken from the engine side of the TB not the induction side.

[Andrew Cooke]

Not sure which side of the manifold your suggesting Andrew but it's currently taken from the engine side of the TB not the induction side.

which is wrong..

[SP33DY]

Admittedly it does say in the destructions that the pressure port should be connected to the inlet manifold.

[Andrew Cooke]

Admittedly it does say in the destructions that the pressure port should be connected to the inlet manifold.

it does, but the throttle should restrict airflow to the engine, otherwise how can you control wheelspin? If the controller is trying to maintain full boost in the plenum irrespective of throttle angle you're going to crash. Thing is, Drag racers don't worry about that, they just want ****loads of boost.

How are the pipes connected to the solenoid? Do you have a restrictor? What are you gain and duty cycles set to? Have you tried upping the gain?

[SP33DY]

The pressure port which provides the readings for the boost controller is tapped into the inlet manifold as we've already established.

The boost controller solenoid is ran from a direct port on the compressor housing through the solenoid and into the actuator.

[SP33DY]

The gain is set at 10 and the duty cycle is set to 50 which did give 22psi.

[Andrew Cooke]

The pressure port which provides the readings for the boost controller is tapped into the inlet manifold as we've already established.

The boost controller solenoid is ran from a direct port on the compressor housing through the solenoid and into the actuator.

OK, so you have 3 ports on the solenoid, and 2 pipes going to it, which is which?

[SP33DY]

The solenoid can be configured for internal or external wastegates but mines (obviously set for internal) with flow from the compressor in on 3 out on 2 to the actuator as per the instructions.

[Andrew Cooke]

The gain is set at 10 and the duty cycle is set to 50 which did give 22psi.

try winding that gain right up, you might want to increase the duty cycle too, I'm guessing here as I don't have your controller. If you could see the duty cycle it'd probably all make sense. Try connecting a handheld multimeter across the solenoid to see what your controller is doing.

[Andrew Cooke]

The solenoid can be configured for internal or external wastegates but mines (obviously set for internal) with flow from the compressor in on 3 out on 2 to the actuator as per the instructions.

Ok, just checked the internals of that valve, as suggested by Ashy, 0% duty will connect the actuator to the boost circuit (low boost), and 100% will block the pipe from the boost circuit, and leave the actuator open to air.

Your problem is either the configuration of the boost controller, or that the controller is junk.

[SP33DY]

I'm pretty sure the solenoid is functioning but your right it could be an error on my part setting it up.

I'll sit down with a brew and the instructions tomorrow and have a look, i might even go to the extremes of putting an osciloscope on the solenoid to make sure the duty cycles are accurate.

Anyway thats me done for this evening, cheers for the help it's much appreciated.

[Andrew Cooke]

I think the solenoid is OK. Can you drive/make boost with the scope connected? Once you drop a couple of PSI below target (22psi?) the duty cycle should have ramped up to 100% to try and maintain boost. It should also be 100% off boost, and until just short of full boost.

Assuming you get it all working, you may find that to make 22psi you need 60% duty at 3000rpm and 80% at 6000rpm (measured on the scope) I'd set the target duty cycle to somewhere between these. As stated in the manual you want the maximum gain that still gives you a stable boost (some up and down is OK).

[Mart]

Hmmm. I thought you mentioned previously that you had bypassed the boost controller & fed the actuator straight off the comp' housing?

If that's the case, that's eliminated any external boost control issues.

Andy, most, if not all, ebc's I've seen fit inline between the comp' housing & actuator, but still take a pressure reference from map.

[Andrew Cooke]

Andy, most, if not all, ebc's I've seen fit inline between the comp' housing & actuator, but still take a pressure reference from map.

maybe that's why they have crap throttle control....

[Mart]

Can't say I've ever experienced that mate.

I don't think I've ever heard of anyone plumbing the map/pressure reference pre-throttle?

[Maka]

I wouldn't go as far as saying loads of cash, just an understanding girlfriend.

Obviously option c could be to stop obsessing with 300bhp and make do with what i've got.

300 horses???

what gearbox you using?
Coops runs 15+ psi on his clio and every weekend nearly in the summer he was fitting gearboxs!!
i think hes pushing 260 ish horses - 115mph approx exit speeds.
thats just off the top of my head.

[Andrew Cooke]

Can't say I've ever experienced that mate.

I don't think I've ever heard of anyone plumbing the map/pressure reference pre-throttle?

no? have a look how the GTT is connected...
my GTiR is that way standard
and any production car that I've looked at.

[Mart]

I thought we we're talking about the (map) reference take off point, not how the ebc actuator control line is plumbed.

[Andrew Cooke]

I thought we we're talking about the (map) reference take off point, not how the ebc actuator control line is plumbed.

we are.

think about it, the controller will do all it can to make the boost you set at the point you measure it.

If you measure the boost post throttle and feather the throttle the boost controller will close the wastegate to try and keep the boost up, until such point that the turbo just can't blow hard enough past the throttle to maintain the boost.

If you measure the boost before the throttle the controller will maintain boost at that point, and your throttle will work as a throttle.

Try it on the Evo, see if it's easier to drive. (note the MAP sensor for the ECU still needs to be post throttle)