Ok.. so here is my problem. I just got a 3" header and my exhaust includes the test pipe and catback are 2.5 inch, would it create too much of a bottle neck? If I use a 3" transition to 2.5" pipe would it help or effect any performance/flow? Should I just return the 3" header and get the 2.5 instead... btw I recieved the 3" header by mistake.

 

Get a 3' exhaust instead, keep the header

 

what other mods? most will tell you to get a 3inch exhaust

 

I got a stock H22, maybe stage 1 or 2 cams setup soon but pretty much stock beside bolt-ons... would a 3" exhaust be over kill for a near stock H22? I just got the 2.5 Apexi ws2 catback and a omni test pipe which I hate to buy a completely new 3" exhaust setup.
Is there any way to run the 3" header to a 2.5 catback without any flow restriction or performance loss?

 

Your setup would run the best with a 3" exhaust.

You made the wrong choice buying that 2.5" exhaust...but we all make mistakes.

If it were me, I'd wait till I had the $$ to put a 3" exhaust behind that header.

 

My car is my summer DD and I plan running 2.5" from the begining... but somehow I recieved the 3" header instead of the 2.75" taper to 2.5" to meet my 2.5" pipe setup.

Thanks... now I know three inch would perform better so I might just keep the 3" race header. BTW money insn't a issue.. it's more of a DD and noise I hate to deal with.

 

my 3" is much quieter than my 2.5" ever was, very daily driver friendly. It mostly comes down to your muffler, don't cheap out on that and it wont sound like garbage. For example I have this and its very deep sounding, don't even have a resonator.
http://vibrantperformance.com/catalo...products_id=50

 

Get a 22" resonator and magnaflow muffler; noise isn't too bad that way.