I have a 2000 SS with mac headers with the cat'd y-pipe, a mti lid, power programmer and 160* stat. It has the stock cat-back exhaust, but i know it has a different muffler and i believe it is a magnaflow by appearance. The pipes are 2 3/4" , so would getting an aftermarket exhaust that is 3" all the way be a wise investment? Mainly im wondering if the stock 2 3/4" is holding me back a little on power.

 

A good cat back system is one of the first mods that should be done to the car. You'll enjoy the feel of your new found power.

 

I bought the car like this. I would have definitely put a cat-back on it first, but im new to the ls1 world. Im just wondering if the power that ill gain from about 1/4" is worth laying down 300-400 bucks, since it already has a more freely breathing muffler.thanks for the reply

 

Yea it's worth it to go with an aftermarket cat back system because the factory pipe is smaller than the 3' pipe that comes with the new cat back system. Plus the factory pipe has bad kinks in it which robe horse power. The cat back systems don't have any kinks so everything flows very well.

 

Gains from stock to a 3" exhaust will be marginal.

 

I dont think that the gains will be significant enough to buy one right now. It will be the first thing that i buy for it though. Although, since i have headers, they wont be able to reach their full potential without a good cat-back system.

 

redhott

the LS1 exhaust in stock form is still mandrel bent, it doens't have the compression bends.

do you know if the inlet of themuffler is 3" or not? if it is i would just call up Dynomax or summit and order the 3" piping from the Ypipe back to the muffler. they sell just that separate.

i know i bought mine off ebay for $125 shipped, and bolted it to my old magnaflow muffer.
lot cheaper than the whole catback