Single turbo Plenum Volumetrics ???

[shaunwil]

There is something bugging me at the minute with single turbos. If the intake track is unchanged and you run a smaller turbo, say a GT35 then why can\'t you run more boost than say a GT42r ? Surely if the volume of the internals of the Plenum and LIM is unchanged so the volume of air wouldn\'t be different between a small turbo chucking out higher boost and large turbo chucking out lower boost.

Why can\'t the guys running smaller turbos just running higher boost levels. As long as you control air temps ?

Shaun

[antnicuk]

part of the answer is heat, small turbos make so much more heat, the air is then less dense and contains less oxygen.  Not sure how more there is to it than that.

Its also to do with the efficiency of the turbo,  a bigger turbo will make the same boost more efficiently/easily which means its not working as hard which also lets more gasses flow out of the exhaust easier which also helps your performance.

Other than that, i dont really know

[shaunwil]

So If you where able to efficiently cool the charge with say WI you should still see much higher figures.

Half of the issue is that we hardly get near to the values quoted as the best efficiency of the turbos we use. Sure I heard that something around 22psi is getting into the efficency band of the the GT35 !

Shaun