Originally Posted by
PhilipA
As mentioned by one of the er "British" posters, I have found a lot of low end to be gained in petrol turbos by freeing up the exhaust immediately out of the turbo.
I had a Charade turbo (don't laugh now) and a Porshe 924 Turbo , and my son a Cordia Turbo . I am pretty intimate with turbos ( and Dynamic Turbos Ltd) as a result.
I had a great low down gain from a large contoured dump pipe from the turbo instead of a right angle bend they had into an empty cat housing (84).
My son also gained quite a bit from a boiler tube exhaust manifold into the turbo in his 84 Cordia pre emission which was FAST. BUt they usually are buggers of things to fit as they often don't allow for such things as actually bolting the turbo on the flange.LOL.
Both will help with quicker spool up but not increase waste gate pressure.
Regards Philip A