Garrett Turbos

[Jamo]

You've missed my point Papvas, you can't measure back pressure by looking at EGT's alone yes it's an indiction but it's not a true measure of any exhaust system backpressure.

Backpressure is how hard the engine is having to push to rid itself of exhaust gasses, the manifold and turbine play a part at the initial point of release.

And the exhaust is like a road, you can have traffic further down the road and not at the start of the initial journey and vice versa traffic at the start and better flow latter on.

This why cat back systems etc can improve performance as the overal complete system must be taken into account.

But saying you don't have high back pressure because your egt gauge at the turbo is measuring near constant is not a true representation of the whole exhaust system.

[A80Avant]

i see your point.
with all your knowledge though,would you pay 200GBP to change the tubing of the cat back to 3inch so that you can say afterwards that you have a true 3inch exhaust system that cannot be the restriction to the engine?Would you see any differences?OR would you have to go deeper to actually get the hp out of the turbo that is advertised?

And to be honest,if garrett says that those turbos produce that hp,BUT @ 2.5bar or something,then how many street use cars can work on these pressures and for how long before something needs replacing?sure than i can get 450hp from the 3071 turbo but only if i have a non restrictive EM,non restrictive exhaust system and turbo working @ 2+bar constant AND having acceptable EGTs....TO me that is a best case scenario,not the common result

PS: any respectable dynos up north east??