I'm running 2" intercoooler piping on my turbo H22, but I was thinking maybe I should go up to 2.25 or 2.50. Would it be worth it? Right now it spools by about 3000 RPM, which is great, but I'm not sure if bigger piping is gonna slow it down.

 

on my h22 turbo i run 2.5" piping throughout, and 3" downpipe....works great for me goign bigger wont hurt but not gonna make tons more power, just help you once you go bigger or add more boost to it...