cats and catbacks
Thread Starter
Launching!
Joined: Feb 2005
Posts: 229
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From: Camp Lejeune, NC
cats and catbacks So i'm new to the ls1's and I've been researching what catback to get for my ws6, I had pretty much settled on the gmmg but after doing some research it seems that you almost have to run cats with it, question is how much does retaining the cats hurt power and what catbacks are good to run with longtubes and no cats?
TECH Addict
Joined: Jun 2005
Posts: 2,660
Likes: 14
From: England
Well here lies a very subjective subject. 
Essentially if all you do is swap the cat back then it's probably worth about 5rwhp or so.
Stock CATS do zap power, but so does the stock mid pipe and headers also. To really see worthwhile gains you need to change the whole system.
Which means LT headers (shorties and mids are IMO not worth it). And either a good 3" mid pipe and cat back or duals.
Technically you NEED cats to pass emsisions, however many people get away without running them. CA is slightly different but that requires a totally different setup anyway.
Good performance CATS will not affect flow or HP to any noticable amount on most setups.
Maganflow Carsound CATS are pretty good for bolt on cammed cars, if you plan on more HP than that then you want Metal Matrix cats, Random Technology and Maganflow both offer these. But so far they are not available as a catted Y so you'll have to custom fab it.
So the answer is unless you have a real special case then running CATS will be of no deficit in any area. An added bonus is CATS general help to reduce any rasp that can occur with certain chambered exhausts such as GMMG and SLP LM. However many people run both exhausts with an ORY and are perfectly happy.
Duals are an option but there's more to consider, such as dumping before the axle, going over or under, muffler type and location, X or H pipe and generally locating them if you want to run a body mounted torque arm.
Duals do generally sound better, but Y setups also sound very good.
As for flow, well a good back is fine as already stated on cammed LS1's so thats over 400rwhp. Also many people have produced well over 650rwhp using a regular catback.
Over 500rwhp a dual setup is probably beneficial though.
Take a look at Texas Speed and Performance, they offer Pacesetter headers and a catted Y for $700 if you think you'll go ORY then the new Edlebrock headers are worth a look. Or lastly if you want stainless steel headers QTP, Kooks and Stainless Works are all worth a look.
Check out www.ls1sounds.com for sound samples of different setups.
Essentially if all you do is swap the cat back then it's probably worth about 5rwhp or so.
Stock CATS do zap power, but so does the stock mid pipe and headers also. To really see worthwhile gains you need to change the whole system.
Which means LT headers (shorties and mids are IMO not worth it). And either a good 3" mid pipe and cat back or duals.
Technically you NEED cats to pass emsisions, however many people get away without running them. CA is slightly different but that requires a totally different setup anyway.
Good performance CATS will not affect flow or HP to any noticable amount on most setups.
Maganflow Carsound CATS are pretty good for bolt on cammed cars, if you plan on more HP than that then you want Metal Matrix cats, Random Technology and Maganflow both offer these. But so far they are not available as a catted Y so you'll have to custom fab it.
So the answer is unless you have a real special case then running CATS will be of no deficit in any area. An added bonus is CATS general help to reduce any rasp that can occur with certain chambered exhausts such as GMMG and SLP LM. However many people run both exhausts with an ORY and are perfectly happy.
Duals are an option but there's more to consider, such as dumping before the axle, going over or under, muffler type and location, X or H pipe and generally locating them if you want to run a body mounted torque arm.
Duals do generally sound better, but Y setups also sound very good.
As for flow, well a good back is fine as already stated on cammed LS1's so thats over 400rwhp. Also many people have produced well over 650rwhp using a regular catback.
Over 500rwhp a dual setup is probably beneficial though.
Take a look at Texas Speed and Performance, they offer Pacesetter headers and a catted Y for $700 if you think you'll go ORY then the new Edlebrock headers are worth a look. Or lastly if you want stainless steel headers QTP, Kooks and Stainless Works are all worth a look.
Check out www.ls1sounds.com for sound samples of different setups.
