Thread: Exhaust size - Opinions 2.5" or 3"

About to swap in VVL in my B14.

Putting in:
JWT POP Charger
Maxima MAF
Ported 2.5" SSAC
JWT ECU(no rev lim) [possible N1 cams]

What size exhaust piping would you guys recommend 2.5" or 3"?

Note: No cat, maybe resonator, wide canister muffler like WS2.

All opinions welcome. Thanks.

I'll go with 3'. A friend of mine tried it at the dyno and got better results that way. And he's got the same header you got.

id say 3'' piping but it could be louder than you may like, but if noise isnt a issue larger is always better

I've always wondered...

Since the collector for the SSAC header is a 2.5", what exactly are the benefits of going with a 3" cat-back? No matter the answer, I'm going with a 2.5" for the next cat-back (call me a wuss), but it still keeps me wondering.

it allows for better exhaust flow since it doesn't have the velocity as it does coming through the collector, as the gasses cool down, they do not flow as good. collector design has alot more to it than just size though, but that is another topic

3 inchs, its a dyno proven fact that 3 inchs makes more power.

i dont know why this is being asked over and over recently.

this is like the s3 vs s4 threads all over agian.

stratton.

I am aware of the dyno numbers. It's just that I've always wondered about the rationale behind all this. totaled's explanation seems to be logical.

yeah, the explanation makes sense, so opinion wise it is more about noise. If you can handle more noise, take the 3", otherwise run 2.5".

Will the 3" WS2 (no cat, no resonator) be extremely loud? what about @4k highway speeds? Would I be able to talk with passengers? If it is girls that talk too much, I guess Iwouldn't mind the loudness. haha

Yes


No

lol

I've been down that road with 3" exhausts before. There is no way I'm putting up with one again on an NA.