I have a catback with a 2.75" I pipe and I was wondering how much power you can put through it before it becomes a restriction.

I have no idea how much power this combo will make but I am wondering if I would benefit any by going to a 3in catback. The motor is a 305 TPI, (TPIS base, SLP runners, LPE plenum, BBK 52mm TB) It has the ZZ4 aluminum heads and the ZZ4 camshaft. I am using heddman 1 5/8" headers and the heddman y-pipe, stock cat and stock I pipe to a flowmaster. So would it make any difference to switch over? If a 2.75" pipe can flow enough I would prefer not to spend anymore money and just use what I got. by the way I am also running a 5 speed if that matters. Anyway let me know what you think.

 

I don't remember the numbers exactly, but it was posted a while back. I believe you want to get 3" pipe when you're in the 275hp-300hp range.

 

Are those flywheel #'s your talking about or at the rear wheels?

Like I said, I have no idea what kind of #'s my combo will put down so does anybody think that the 2.75" will be restricting power and if I went up to a 3" pipe how much extra power could I get?

 

Yes, those are flywheel #s. With your setup with the heads and cam, I would definately get the 3".