catback 2.5" or 3"?

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Unless you have plans on running a really high boost twin screw (25+psi) in the future I think you're better off with the 2.5 inch. The 3 inch is overkill unless you are passing some serious spent gas. You need to maintain a small amount of back pressure for the engine to run at peak efficiency.

I think my Magnaflows have 3.5 in tips. :scratch: They fill up the bumper cutouts quite well.

You could always go for the 3lb coffee can tips if you really want to impress the ricers. That's what I do when I go out cruising.... :rlaugh:




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New Member
Apr 15, 2005
I gained 2 mph consistently with the MAC 3" over the 2.5 Stinger kit I had. I also noticed a considerable seat-of-the-pants difference top end. I did lose a little down low on torque on the dyno, but it pulls harder up top.

I do have plans for a twin screw though and that is the only reason I got the 3".

But for the record, before the 3" I ran 120, now I run 121.5-122 consistently.

I like the 3.5 tips the best, but my old Borla 4" tips looked sick. If you do go 2.5 though, buy the SLP double wall tips....those are awesome. I even have a brand new unused set if you are interested.