I wanna do my whole exhaust system but I want something different. Its an 89 rs Lo3
I was think of something like this:


I would probably leave the stock Y for now since Id rather get headers at the same time but I would probably tell the muffler shop to use 3" piping after the y pipe tell them to use a clamp since the stock y pipe is smaller than 3" and besides they always strech it again. I was also thinking of a high flow 3" in cat and then a 3" magnapack with a turn down. I dont care about looks since it might look stupid with just 1 big turndown.
but i think this should sound pretty nice save some weight and reduce backpressure.

What do you guys think?

 

It will flow better, but the stock manifolds & y-pipe are a pretty significant restriction themselves.