So Im wanting to go 2.5 inch. Does anyone make an over axle section for this? Ive seen under axle 2.5" but Im afraid of ground clearance as my car is lowered..Any help appreciated thanks!

 

I'm no expert but from what I'd read here is that 2.5 is to big for the engine displacement. I'm sure someone else will chime in. Stock pipes are 2" and I think I remember 2.25 as about as large as you should go. Something about keeping the back pressure correct for the engine displacement.

As for under the axle if you are lowered I'd be concerned.

 

I have a 2.5" cat back system and saw no loss of power (but no gain either). Sound is awesome though.

It is an under axle setup but I haven't had any clearance problems even with the Adamesh lowering springs. I do, admittedly, live in the southwest where roads are good and winter nonexistent.

 

I have 2.5" cat back, but it gets smaller over the axle. It's fully custom.

 

For those under axle guys.... I was thinking using oval tube sections under axle. A 2.5" pipe is 3"x 1 3/4" should help with ground clearance issues