I've been told that an exhaust system is only good for performance engines, not stock ones. Is this true? Should i even bother with an exaust system? If so, what brand would you guys suggest. I don't really care about sound, just performance.

 

The stock exhaust is very restrictive on these cars. So just about any aftermarket system will make more power.

Talking about cat-back systems: Brand is mostly a matter of sound preference or cost. Many will say one will flow better than the other, but in reality we're talking a minimal difference on a stock engine. Maybe 1 hp. Just pick one. You will want a 3" mandrel bent system. Don't bother with anything smaller or non-mandrel. Should be worth around 7-10 hp even on a stock engine.

Headers get a little more complex...

BTW - knowing which car/engine you have is always helpful

 

Exahust can be improved on almost any car no matter what the output. You will see gains even on your stock motor. Cat-back gains will be minimal because you still have the restricitve headers and cat but when you get rid of those and have a complete system you will see nice gains.

 

I'm going tomorrow to check out an 88 Iroc. It has a 5.7. I'm not sure what that will mean for the exhuast system. I hear that changing the headers adds about 15 horsepower. What can i do with the exhaust system? What should be the first mods i do if i get this car?.