JMon

Is there any bolt on pipes I can use to just drop out my catalytic convertors? I want to be able to pop the stock ones back on when I have to pass emmisions.
What are the HP/TQ gains? Any downside to this?

ICULUKN-C5

Downside is that you will still have pup cats, and they are more restictive than the catalitic (sp?) converters. I would keep the converters and get rid of the pup cats, IMO. Anyway to answer your question, you would have to have a shop make you a couple of custom straight piped with flanges to relace the cats.

JMon

I think I just have the 2 catalytic converters on my car no pre-cats.
I'm also not sure about the whole back pressure issue.
Would I be any better getting hi-flow cats?

Pat97Vette

Yes, you have 2 cats only on your 97.

97C5ENVY

There are no "bolt on" cat replacements. You have to make your own. What i did was buy an old stock H-pipe (the portion that gets replaced by a Corsa X-pipe or Bassani X-pipe) from a forum member. Then i bought the MTI off-road X-pipe(designed to be used with the TPIS long tube headers) and had it welded to the old stock H-pipe.......had to put a 10" extension in between for each pipe to get the overall length right.

By doing it this way i was able to keep my stock intermediate pipe w/cats (the section of exhaust from the collectors to the flanges of the "over-the-axle-pipe"), and could swap this section out when needed with my "off-road" set-up......and vise-versa. :yesnod:

As for HP/TQ gains......well see this thread and you decide:cry http://forums.corvetteforum.com/zerothread?id=405226


[Modified by 97C5ENVY, 12:07 PM 10/8/2002]

vstella

Check with Robert of Florida Performance in Fort Lauderdale..954-491-1012. He is a master welder and has done this before for some members...Tell him I referred you!:D

0Sales@MVPAutoParts.com

JMon,

I strongly advise against this mod on a stock cubic car. It was done on my car and I ended up loosing about 5rwhp/tq instead of gaining. I don't think it is worth the hassle if you're after the hp gains. But if you're going for the loud muscle sound, then I say go for it.

:cheers:
-Tuan

JMon

Actually I read one of your old posts where you actually lost 10hp.
Now if only I could make my C5 sound like my old Firehawk (with gutted cats) I would be so happy. Baddest sounding car I've ever heard. I don't mean extremely loud but loud enough and deep as hell.
SLP told me that no matter what I can't make an LS-1 corvette sound like my LT1 hawk.

0Sales@MVPAutoParts.com

Yeah...I lost track of the actual number. But in that post, I did include the before and after dynograph. :cheers:

I may go back to stock exhaust after the 408 motor goes in. That is to keep the noise level down when I'm hauling azz on Sat night.:D

carpe dm

NOT worth the effort, or the potential problems. In addition, although some don't like to face the truth, it is a federal felony and you are contributing to the polution factor. :smash:

Shinobi'sZ

To answer your question and not your ethics it is quite simple and you will see some gains.

Either:
A. Purhase the FLP complete exhaust system from Nate @ Xtrememotorsports.

B. Purchase an off road X pipe from BPP or have a muffler shop make you one, weld flanges on it, and then weld flanges to your cats and wah lah you have a bolt in system.

I had a 97 and bought an xtra mid pipe at a junkyard for $250, I can swap in and out the system in about 1/2 hour. Use the 02 simulators, that way you don't have to get LS1 edit and delete or install the rear 02's everytime you wish to swap back and forth between an off road and street setup.
Good Luck.

PS I don't know how anybody ends up seeing no gains by opening up their exhuast. I guess they skipped the part about dynoing with open headers. The more your exhaust flow the better...period. I have done this mod and on my old 97 picked up 7 RWHP and 12 RWTQ. I did this mod to my Z and it is very noticeable...especially since I have to let off the gas to get traction now when shifting into 2nd @ WOT, prior too (4 hours before) with the stock manifolds, pup cats, and cats, I could stand on the throttle and my 335 size tires would spin some and then catch...now they just light up if I don't back off the throttle...that is more torque my friend.

jschindler

JMon

pollution? You should see my jet ski now that's pollution!!! :eek:
After reading Luan Le's old post I'm not going to do it. I might if I got like 30hp or something but for little to none or even - I won't bother.

I didn't know it was a federal felony! So if I got caught without cat's 3 times I got life? MAN! Funny thing is my VW bug is perfectly legal with no cats, but my nice fuel injected corvette I can get thrown in jail if I pull the cats? I can't believe it would be a felony....

Big Carrot

You wouldn't want to kill a spotted owl or anything, but I GAINED 14rwhp and 7 lbs of torque. Sounds much better and runs a little better. I wouldn't do it if I was you. :lol: :lol: :lol:

Pat97Vette

Nope. You can be fined up to $25,000 per offense due to tampering or replacing before the old one is worn out, according to the Clean Air Act. Unless you are gutting cats for profit, multiple times, it may not be worth the EPA's time to go after individuals. Then, of course, they have to prove you violated the law, which is difficult. Unless you get on the forum and brag about tampering or replacing your cats, then you just admitted your own guilt in writing, on a public board. I've seen many owners do this, which is kind of dumb. If the EPA ever wants to start issuing violations, they got all the confessions right here.

chuckster

I GUTTED MY CATS!!!!! Neener Neener Neener.... :p: and I have pictures to prove it...

Oh ...And Spotted Owl tastes like chicken... :p: :p: :p:
and I speed when nobody is looking... :D




[Modified by chuckster, 8:59 PM 10/8/2002]

6500RPM

(So if I got caught without cat's 3 times I got life? MAN! Funny thing is my VW bug is perfectly legal with no cats, but my nice fuel injected corvette I can get thrown in jail if I pull the cats?) :lol: :lol: :lol: