DarkBlue88

The mod bug is hitting me on my 88, which is stock 126K mile car. Heck it still has the frizbee on it. The right muffler is rusting at the seams and it has the 2.59 exhaust with the blocked left port. The stock exhaust also looks like CRAP from the back since the car is perfect paintwise. I'm almost sure that the pre cats aren't clogged, although it does get quiet in the high rpm's. I was thinking about doing a Carsound cat, Corsa cat back, and a pre-cat eliminator pipe, then taking it and having the entrance seam to the cat welded up, since the muffler shop won't know the difference. I don't intend on buying intake runners or a cam, so I need tips on whether to go 2.25 or 2.5 SS on the cat elim pipe.

daytonaer

The stock front pipe looks to be 2.25, I put on a 2.5 front pipe (cat eliminator). I wish it was mandrel bent, the crimp bends look restrictive, but less so than the stock crimp bends.

A new high flow 3 way converter after the y pipe should clean up the exhaust as well or better than the 3 stock cats.

If I were to do it again I would: weld up a 2.5 pipe with mandrel bends or do nothing and save for long tubes simply because I struggled so much with the stock manifold studs. I had the manifolds off and the car apart, if the long tubes were there, they would have gone on easy.

The larger y-pipe is a great cost/benefit ratio, the corsa is a great sound/looks/performance set up but you pay for it. In my opinion the corsa setup would be great with long tube headers for great performance sound and looks or the front y pipe/high flow cat/muffler eliminators would be a good performance/budget setup.