Just wondering what performance increases could be expected when changing from a 2.5 inch dump pipe to 3inch (considering no cat & rear muffler is very free flowing).
Additional info on the car is stock port s4 13bt, stage 1 highflow turbo, microtech ecu, FMIC, injectors, fuel pump......running 13psi.
Currently ive ben dyno'd at 265rwhp on a very conservative dyno (usually reads around 20-30rwhp less than most other workshops inflated power figures).
Could i expect to gain much in power output?
Or would i just see improvements in power delivery?

Im just trying to work out if its worthwhile pulling my highflow out & getting the wastegate done or not.

Any advice would be greatly apprciated.