what size exhaust?

Im gettin my custom exhaust this weekend. im goin with a straight pipe all the way back to a straight through muffler, what size piping should i get to optimize hp? i heard if u go to big, u lose backpressure which means lose hp. whats a good size to obtain peak hp? thanks

2.5

between 2.25 and 2.5 and you can't go wrong

2.5

thank you

NA D16? 2.25 would be fine.

But for a B18C, 2.5 fo sho.

sweet, thanks dude.

oh and on the vtec situation i think im gonna do an rpm switch for now till i get some money for a p28 and harness convertor and a vafc. anyone know where to get one? i know, i know, the magic word ...."EBAY!!!"

id still go 2.5 on a d16, back pressure is bad

id still go 2.5 on a d16, back pressure is bad

2.5 is a little too big for d16 unless you got turbo. Trust me, I've tried it and it sux. Sometimes back pressure is a good thing, especially when you have little torque and you want to go up steep hills...

soooo.....2.25?