Cats or No Cats? Help decide...
Drifting
Joined: Apr 2004
Posts: 1,530
Likes: 250
From: CT
The hp loss depends on what engine mods you've done. On a stock LS1 I doubt that you would see more than 1-2 hp difference with the high flow cats. I lost about 5 hp adding Random Tech cats to my LG long tube/ 3" X pipe, corsa setup (431 to 426 rwhp). Thats with a head/cam package and a pretty agressive cam. I don't race the car so no big deal losing 5 hp. I do think the car sounded better w/o the cats and personally I actually liked the slight fuel smell, but at least now I don't feel guilty about dumping all those hc's into the atmosphere.
Instructor
Joined: Dec 2003
Posts: 215
Likes: 0
I vote for no cats. I have a 432 stroker with 17/8 Kooks, 3" off road pipe and stingers, it sounds 10 times better with out cats. The smell is great but I burn 110 octane sunco. If you want a quiet and a good smelling car get a mini van.
Drifting
Joined: Dec 2003
Posts: 1,586
Likes: 72
From: Upstate NY
You can get the best of both worlds by buying FLP LongTube headers with Off Road Pipes and hi flow cats. That's what I have and switching out the ORPs for the cats is a 15 minute job. The cons of ORPs are a slight smell at times, increased carbon build up on the tail pipes (as someone else here mentioned) as well as not being environmentally friendly. On the positive side I think the ORPs sound awesome and louder at WOT, scares old ladies on the side of the road. I definitely reccomend the FLPs if you're unsure of which way to go, not to mention ease of installation of the whole system. 
Racer
Joined: Jan 2003
Posts: 405
Likes: 0
From: Coconut Creek FL
Hi Bill,
Just got on-line tonight and saw this post. Try 'em without the cats first. True, the LG hi flow cats only choke about 1hp, but no need spending $$$ if you don't have to. I really don't think "smell" will be an issue, but try it and see. If you're okay...great. Otherwise, get the cats from Lou and quiet it down and knock down the stink. Just try it first before you spend the $$$...no sense blowing cash on something if it doesn't bother you.
Rob
Edit: Bill just purchased my LG Pro LT headers. The LG's have off-road tubes that are easily "swapable" for cats. (Similar to the FLP system, but no broken tab problems, and all stainless.) Just suggesting he try them (catless) first to see if it causes any concerns, before he buys cats.
Just got on-line tonight and saw this post. Try 'em without the cats first. True, the LG hi flow cats only choke about 1hp, but no need spending $$$ if you don't have to. I really don't think "smell" will be an issue, but try it and see. If you're okay...great. Otherwise, get the cats from Lou and quiet it down and knock down the stink. Just try it first before you spend the $$$...no sense blowing cash on something if it doesn't bother you.
Rob
Edit: Bill just purchased my LG Pro LT headers. The LG's have off-road tubes that are easily "swapable" for cats. (Similar to the FLP system, but no broken tab problems, and all stainless.) Just suggesting he try them (catless) first to see if it causes any concerns, before he buys cats.
Last edited by FRC Rob; Jul 1, 2005 at 12:07 AM.
Race Director
Joined: Feb 2003
Posts: 11,133
Likes: 1
From: ~The DARKSIDE Group~
Originally Posted by 1stC5weiss
In looking at adding LT headers, I have to decide on hi-flow cats or go with NO cats...I'm here in Florida so no emissions testing here. What about the Smell everyone claims you get with running no cats? What's your opinion?
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