upping the rev limiter?

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06-25-2008, 06:25 PM

#21

paul_dezod

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Quote:

Originally Posted by Guru

Quote:

Originally Posted by B_Real45

Quote:

Originally Posted by Guru

I have soft limiter at 6800 and hard limiter at 7000 on most Hydra cars I tune but kinda pointless really. Peak power is at 5500-5600 RPM even on larger frame turbos like GT35R's. To go beyond 6000 is just putting wear and tear on the engine with no speed advantage. This is on the 05-06 motor. The 07-08 motors there may be a small advantage since peak power is a few hundred RPM higher.

Guru,

Is that true even when using larger exhaust housings?

Even on a 0.84 AR exhaust housing it is true. I will be trying out the 1.01 AR once available for the GT35R SS HTA.

On what kind of manifold and what AFRs? Any head work done or cams as well?

06-25-2008, 08:00 PM

#22

Ace83

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Quote:

Originally Posted by paul_dezod

Quote:

Originally Posted by B_Real45

Right Paul.. that's obivous. I was referring to his GT35 comment. It's a fairly large turbo - and yet he was still not gaining any power in the upper rpms.

I was wondering if they had tried larger exhaust housings (all else stock or the same) - my understanding is that the larger exhaust housing will shift the power band to the higher rpms.

Maybe someone can do this experiment. Take a pretty much stock tC and put a turbo kit on - dyno that and change the exhaust housing and redyno - just to see the effects.

Turbine A/R and design of the manifold will have all of the bearing in the world. Say a selection of an .82 A/R vs a .63 A/R will suite better to a higher redline.

So what engine mods will I need to utilize the higher rev limit advantage, I thought the 0.63 a/r is a lil big for the stock tc motor/rev limit.. and a tubular manifold will do better?

06-25-2008, 08:18 PM

#23

paul_dezod

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Quote:

Originally Posted by Ace83

Quote:

Originally Posted by paul_dezod

Quote:

Originally Posted by B_Real45

Turbine A/R and design of the manifold will have all of the bearing in the world. Say a selection of an .82 A/R vs a .63 A/R will suite better to a higher redline.

So what engine mods will I need to utilize the higher rev limit advantage, I thought the 0.63 a/r is a lil big for the stock tc motor/rev limit.. and a tubular manifold will do better?

Far too many variables to discuss that could effect turbocharger onset. With respect to motor & turbo:

Camshaft Profile
Head Design & Work
Intake Manifold Design
Exhaust Manifold Design
Turbocharger Trim w/ Turbocharger Turbine Arrangement
Tune & Engine Management
Exhaust System Design and Diameter