deviant1

is 2.25 inch exhaust piping big enough for a greddy 18g kit on a b18b1? is it big enough to handle about 200 whp?

SoulSurfer

I don't know for sure whether or not you can squeeze 200hp out but 2.25" is going to restrict your power output for sure. If you can get a 3" you will have a better shot at making power.

Poop111444

My buddy has Greddy Turbo GSR and he is running an Apexi N1 which is 2.25" Generally speaking that is a wee bit small for turbo....but the downpipe for the Greddy kit is only 2" ! Would it still be beneficial to upgrade the exhaust to say 2.5?

Flamenco-T

you can never be too big with turbo

deviant1

good question. i would like to know as well.

T3

IMO id say 3''..But thats just me.

BoostedSi

i'd use at least a 2.5"

mamaboy

i'm doing 2.5" from downpipe all the way back....don't think i really need a 3" for a the amount of boost i'm doing

deviant1

would it be the same as a 2.5" or 3" exhaust system if you originally had 2.25" piping including the muffler, but later upgraded the piping only to 2.5 or 3", leaving the muffler on and having the 3" piping taper down to whatever the muffler section is?

red_sir

No, the muffler will still be a bottleneck.

Kwuaymaikrup

I say go with 3'' now and save yourself the trouble in the future. I mean how long is it going to take untill you want (sorry I meant NEED) to up the boost?

-Ryan

SOHC_MShue

i feel the NEED for boost