I have stock exhaust and Im not going to be putting aftermarket exhaust on for a awhile b/c im save for a ls/vtec convesion so should i cut my stock cat out and just weild a pipe in its place. Just see if any one had done this or if they knew if it sounded bad or if after i cut it out would there be visible smoke coming out of the muffler. im not worried about smog carp because they dont test here any more. Also i douted it but would it help the proformance at all???

 

do it, man. youll just get more of a potent exhaust smell but it isnt bad at all. dont worry.

 

will it sound alittle better

 

I wouldn't do it. On an almost stock engine you'll gain maybe a whopping 1 HP and it will probably sound louder and besides.... I like breathing...

 

NO you're just bolt ons

 

Don't. Don't kill the environment and Don't risk getting a very large fine $1000-5000 for gaining a measley 1HP.

 

just stay stock until you get your lsvtec

 

Don't do it... It's illegal, it pollutes the environment more, you won't pass emissions, and it won't do much for performance. If you gut the thing, you'll likely have less back pressure, but more noise and fvcked up exhaust flow. From what I hear, gutting the thing takes a lot of force directly to the inside of it, so it's not like you're going to be able to say "my car bottomed out at hit the cat" or "it just wore out". As far as I know, it's a pretty big fine if you get caught, and for good reason.

Keep your stock cat or get a high flow cat, those are the only respectable choices. Don't gut it and don't get a "test pipe". And just FYI, many of the "performance" or "high flow" catalytic convertors being sold on eBay are nothing more than illegal straight through "test pipes".

 

Weston: Less backpressure is a bad thing? I think not. Do get a test pipe for the track, I'm not going to lie to you. Test pipe will make about 5WHP. But it's more of a moral issue than anything else weather you get a high flow cat or a straight pipe. It's up to you.

 

He's not pushing enough air from a stock LS to see benefits from a test pipe. The car will be sluggish at the low/midrange due to loss of backpressure, and the LS lives in the midrange, not the top end where a test pipe makes power.

 

How about an LS with I/H/E already, and maybe a Nitrous system? My friend has that setup and he's using a test pipe. I don't think he lost any low end power either.

 

With nitrous you are flowing a lot more air than an LS with just I/H/E. IMO a test pipe on an LS with just bolt ons is not necessary. Once you are flowing a good amount of air through it like on nitrous, other FI, or a more built all motor setup, then you'll see good gains from a test pipe. I put a test pipe on my LS with just intake and exhaust just for the hell of it. The car didn't really want to move until I got past 5k, but I did pick up a little bit in the top end, but not much. It did make a good difference the run I sprayed though. I'll probably get one after I get my new nitrous setup for the track.

 

I never said less back pressure was a bad thing... I said he'd have less back pressure, but more noise and messed up exhaust flow. The bad exhaust flow would come from the fact that cat is all tore up and uneven inside; even if it were completely cleaned out, it would still be letting the exhaust gasses expand into a larger area and then they would have to condense to get out. It doesn't take much of an understanding of physics to see that a test pipe or high flow cat would be better. And if you're going to buy something either way, then you might as well get the high flow cat so you won't be an a$$hole to the environment and everyone trying to breathe around your car.