Exhaust Configuration

#1

I did a search, but I’m not sure the comments I read are as up-to-date as the rules are. I know you can dump the cat. Is there any reason you can’t run 2 pipes from the end of the headers all the way to the end of the car, exiting where the original exhaust does - that’s it? I know you would probably need a couple glass packs or something to make sure you are legal for tracks with sound db limits, but, as the rules read, I don’t see the requirement for a muffler or cat - is that correct?

Thanks!

#2

That is technically illegal. You must keep everything stock from the exhaust header all the way to the front of the cat. This includes the X-pipe (H-pipe) section that is in front of the cat. After that, you can run 2 pipes all the way back.

#3

That clears it up - I understand the issue now. Appreciate the quick response!

Thanks!

#4

What is the consensus on the best setup for this? Is it just straight pipes and lose the cat.

Searching some older posts it looked like dumping the cats (or gutting) and adding glass packs were the preferred setup.

#5

I think its pretty much agreed that removing the cat will free up the exhaust and improve overall power. From what I’ve read on the forums I don’t think there is a concensus on what the "best" configuration is after removing the cat. ie, pipe sizing, glass packs, muffler(s) or nothing. I guess if anyone has taken the time and expense to find the best setup they would want to just share it with the competition would they? :whistle:

#6

I guess I’ll have to go buy one of those big mirrors the emissions dudes have.

btw this was meant as a haha.

#7

Al said in another thread that he got 3-4 hp when he took the muffler off at the dyno. I don’t know what kind of muffler he’s using though.

#8

mskeen wrote:

Single cherry bomb-style glasspack.

#9

I put two glasspacks inline on mine. They are straight through units from Magnaflow, good quality and affordable. When I had a 318 street car with straight pipe all the way back is was nearly unbareable with interior in the car. Stripped out it would have been ear peircing. It seems to flow relatively well and noise level is under control.

I used two glasspacks mainly to add weight to the 318 not just sound level. My car is so severly underweight I’ll need that extra weight down low so that with the max amount of lead the car will be legal weight.