ok...I was more less talking about back pressure here. you said there would be less back pressure going with a 3'' reduced to a 2.5'' than just haveing a straight 2.5''. I dont see how thats possible. And with less back pressure on a roots style setup you would have less boost correct? keeping the same size pulley of corse. shoot the stock is close to a 3'' anyway besides where the the flange in welded to the stocker at...and it's only 10 bucks more....Im not trying to argue or be right...but rather to learn something in the process.
I could see what you are saying about it acting as a collector.But the back pressure would be greater at the reduced point instead of being greater at the manifold to downpipe point....wich at full throttle (or long enough to build equal pressure from the reduced 2.5'' point foward) the pressure would eventually be equal wether there is a 2.5'' or 3''....am i making sense?
