wwhat are the pros and cons of a 2.5 inch cat back system as compared to a three inch? I have seen dyno charts where both sizes have shown significant gains I just ordered a scoobyssport 2.5 inch and i'm wondering if i should have gone with the Blitz 3 inch any suggestions

 

yes an 02 wrx wagon

 

3" catless if you want to make power. The Blitz or HKS are real good IMO.

 

I cant remove any cats or my dealer will void the warranty, and they are real tough about it. They go as far as pulling out the enginge computer codes and info on everything if they suspect you are just replacing the factory an exhaust for a trip to the dealer. They busted one guy for an aftermarket clutch because the head tech drove the car and found the pedal so much heavier! tough break for me. Gotta play by their rules in case something goes wrong in the future.

 

You are right, I will void only certain aspects of the warranty, but my dealer is hardcore, I have seen them take video and written damage reports on WRX's to prove that aftermarket parts were at fault. I need to find a more lax dealer - about 50 miles away.
They are evil and cruel and must be dealt with! I am putting my money on the scoobport system 3 inch downpipe, and a front center section 2 pieces and a rear center section that tapers into a 2.5 inch exhaust muffler section, 4 parts in total, all easily removed for trips to the dealer. Hah I will fool them! Tad

 

I'm staying under 300 hp so 2.5 should be ok, If you can explain a litlle more I will not be offended, I have heard 2.5 will give you a broader torque curve and still some gains on top. If you want just e-mail any theory you have on exhast because I really need more information. Tad