Honestly if I could have done it again I would probably go with the aluminum because mine is still rusting at the welds. The stainless is not rusting yes...but where they welded it is. So essentially my exhaust will still fall apart at some point. I am not downing it, I'm not sure there is anyway to weld that is anti-rust, but that is where mine is rusting. I have had mine for about 2 years now and the piping still looks good, just some welds are rusting.

 

2.25" flows better with less backpressure than 2", but 2.5" can potentially flow with MORE backpressure than 2.25"... it depends on the motor and exhaust. I honestly do not see the benefit with the N/A Neon motors to go with the 2.5" over the 2.25"...

Going with the larger 2.5" over the 2.25" ultimately allows the exhaust gases to stay inside of the pipe longer, which gives them more time to cool down BEFORE they exit your vehicle at the end of the pipe. This cooling makes the gases denser, and creates it's own backpressure as it is forced to travel down the pipe. It is a good idea to run at least 2.25" but remember you need to keep the exhaust gases as hot as possible while they are still in your exhaust pipe... A 2.5" pipe will hold almost 25% more volume in it than the 2.25" before it exits your vehicle...

The 2.5" is a good idea for high-performance race engines or turbo- or super-charged applications, but ask any small- or big-block guy who's serious about winning money every week at the local dragstrip, and he'll tell you that there IS definitely such a thing as too big of exhaust, just like too small, and how much it can cripple you.

 

I'd say go with the 2.5 Stainless steel exhaust. If I could do it again I'd get a Stainless steel exhaust. I'll probably end up getting one later on.

 

I'm rather torn as to the pro's and con's between the 2.25" and 2.5" exhaust...I would suggest unless your planning on modding the engine more (60mm TB, Magnum Intake Manifold, LTH, MTH, STH, P&P, Magnum head swap, aftermarket cam, etc...) just stay with the 2.25". If your planning on doing all those things I listed in the future you might as well go for the 2.5" exhaust, otherwise, just stay with stock size piping...but thats just my opinion on the matter.

 

I didn't specify why I suggested a 2.5 inch but I couldn't agree with 03neonRT any more. Since he's planning on going deeper into the modifications, that's what I suggest.

 

Geeeeeez

 

Ok...

 

n/m, I was just saying that because when I first read his response it sounded like a big contradiction but I re-read it and now I think I get what was meant by it...