I'm thinking about tinkering with my stock exhaust. I've got a 2005 Supercharged SS, so it's the L67 engine, and for now I just want to replace the downpipe & cat, going with a hi-flow cat, and the U-bend delete. I don't race the car - the only time I ever "get on it" is on the interstate trying to pass/get out of the way of the big rigs. That supercharger really shines in those situations.

My question is: do I need to go with a 3" downpipe, or would I be better off with a 2 1/2". I noticed ZZ Performance offers both the 2 1/2" and the 3" sizes. If I wound up going with a 3", would I lose low end torque/streetability? I'm going to hold off on any further exhaust mods for now until I see how this works out.

Also, ZZ Performance advertises that their 304 stainless steel as being better than the more common 409 stainless. Any substance to that?

Thanks.

 

For an L67- do the 3" period. The 2.5" is available for the NA L36 guys.

 

3 it is. Thanks.

 

Yes, 3" only for the L67, and the 409 is general duty stainless for exhaust systems, while the 304 or 306 is higher quality, and can be polished if wanted.