924 RWHP TT 2019

[gimmie11s]

Thanks the first pull was 914 and the second one was 924, I stopped there but a part of me wanted to turn up the boost to 15 psi which would have made 4 digit power but I refrained lol.

Thats funny.. my story is damn near the same. I made a few pulls at 7.5-8 psi.. moving to 10-11 psi where the car made mid 800s.

Last pull i turned it up to 13 and it belted out 913 whp. The dyno operator was shocked (small town, local guy) and wanted to keep going.

I kindly said HELL NO and turned it back down to 8 psi and drove home HAHA.

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[kcc0521]

Same story here. My friends wanted to see 1000 and I wanted to keep the rods in the motor.

 

[Black Dog]

What size turbos?

 

[pro 5.0]

turned it back down to 8 psi and drove home

I told myself the same thing turn it back down to gate pressure which is 8 psi and be safe, that lasted 1 intersection then back up to 12 psi it went lol.

 

[pro 5.0]

Same story here. My friends wanted to see 1000 and I wanted to keep the rods in the motor.

Easy to say when they aren't cutting the cheque if it let's go, for some reason the goal of 1000 rwhp is a mystical number that just needs to be achieved lol.

 

[pro 5.0]

What size turbos?

Gen 2 oil less Comp turbo's 62/62
.82 AR, I feel it could benefit from a bigger turbine wheel though.

 

[sigintel]

Gen 2 oil less Comp turbo's 62/62
.82 AR, I feel it could benefit from a bigger turbine wheel though.

Spools faster than needed?
Ends up bypassing quickly?

 

[pro 5.0]

Spools faster than needed?
Ends up bypassing quickly?

Turbo's light around 5000 rpm I've had it at 15 psi on the street and the car doesn't seem to pull clean in the higher rpm's, I think it's floating the valves due to a backpressure issue. This same kit worked flawlessly on my 2015 at 16 psi but I believe this Gen 3 motor with the higher compression and better cylinder heads flows a lot more air than my Gen 2.

 

[sigintel]

Turbo's light around 5000 rpm I've had it at 15 psi on the street and the car doesn't seem to pull clean in the higher rpm's, I think it's floating the valves due to a backpressure issue. This same kit worked flawlessly on my 2015 at 16 psi but I believe this Gen 3 motor with the higher compression and better cylinder heads flows a lot more air than my Gen 2.

Thanks.
Wont be going for max power w TT, but l will road course it.
I could see going oversize turbine to lower back pressure and focus power in 5-7.5k rpm range for road course at 750 rwhp peak on E85.
Kinda toying with just sell it for a GT500 or C8...

 

[pro 5.0]

Kinda toying with just sell it for a GT500 or C8...

Either of those cars would be bad ass, but IMO I wouldn't want to modify either of those cars they are just too much money to be messing with.

 

[gimmie11s]

Turbo's light around 5000 rpm I've had it at 15 psi on the street and the car doesn't seem to pull clean in the higher rpm's, I think it's floating the valves due to a backpressure issue. This same kit worked flawlessly on my 2015 at 16 psi but I believe this Gen 3 motor with the higher compression and better cylinder heads flows a lot more air than my Gen 2.

It is back pressure. What is your exhaust set up? Mine floated the valves above 10 psi when I had the stock cat back.

I installed a custom 3” all the way from turbos to tips with straight through mufflers and now it pulls absolutely clean as can be all the way to 8k on 13 psi with 0 float.

The valve spring installed height on the Gen 3 cylinder head is almost a 1/4 inch taller on our motors vs Gen 2.

This is why we float the valves at lower boost.

Short term answer open flowing exhaust.

 

[pro 5.0]

What is your exhaust set up?

Full 3 inch from the turbo housing's into a Corsa 3 inch active valve exhaust, the Corsa mufflers with the valves fully open is basically a straight pipe.

 

[gimmie11s]

Full 3 inch from the turbo housing's into a Corsa 3 inch active valve exhaust, the Corsa mufflers with the valves fully open is basically a straight pipe.

And it still does it with the valves open? Could be the turbine wheel I suppose. Mine are 65mm.

What spark plugs and what gap?

 

[pro 5.0]

And it still does it with the valves open? Could be the turbine wheel I suppose. Mine are 65mm.

What spark plugs and what gap?

Valves open fully when you go WOT regardless of which mode you are in, also the wastegates are vented to atmosphere that combined with a full 3 inch exhaust leads me to the turbine wheel being the issue. I originally had the Denso ITV 24 plugs gapped @ .025, then I switched to the NGK 6510 gapped to .018 no difference. At a .82 AR housing that is plenty for this size engine a simple valve spring change would probably fix the issue but I wouldn't do that in frame, at that point you may as well build the short block but that is another 10K cost at least no thanks lol.

 

[gimmie11s]

Valves open fully when you go WOT regardless of which mode you are in, also the wastegates are vented to atmosphere that combined with a full 3 inch exhaust leads me to the turbine wheel being the issue. I originally had the Denso ITV 24 plugs gapped @ .025, then I switched to the NGK 6510 gapped to .018 no difference. At a .82 AR housing that is plenty for this size engine a simple valve spring change would probably fix the issue but I wouldn't do that in frame, at that point you may as well build the short block but that is another 10K cost at least no thanks lol.

Yep couldnt agree more. Funny i started on the Denso's also (Lund's suggestion) and i switched to 6510's and the car runs better. I think mine are gapped at 22 or so. Im also on .82 housings.

Does your exhaust have an H or X mid pipe? Mine had an X but i eliminated it when i built the 3" exhaust. It doesnt sound as nice as it did with the X, but it no longer floats the valves so i plan to keep it out for now.

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