# are catback's worth any hp gain?



## jmd (Sep 29, 2006)

i have ordered American racing headers with cross overs and o2 pipes all the way back to the stock muffler. the mechanic at jamison's corvette, said cat backs are not worth it only a 2-3 hp gain and it takes away form the sleeper look , i want and makes it extremely loud. is there a big hp difference i may be missing? any opinions? tks.


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## fergyflyer (Apr 18, 2005)

jmd said:


> i have ordered American racing headers with cross overs and o2 pipes all the way back to the stock muffler. the mechanic at jamison's corvette, said cat backs are not worth it only a 2-3 hp gain and it takes away form the sleeper look , i want and makes it extremely loud. is there a big hp difference i may be missing? any opinions? tks.


I'd say the guy at Jamison's would be glad to take your money and fit an exhaust if he thought it would help. My guess is he's being honest with you in regards to what he see's on Corvette's. On a C6 the most open cat-back you can get is good for 5hp and most are barely break even. 

The GTO is slightly different. When you look at the stock pipes, there are some major kinks going past the axles. So it depends on where he ends with the pipes he is running from the headers. If he makes it over the axles, I'd guess no gain to 3 hp with mufllers. If he stops short of the axles, I'd bet you would get 10hp. and if he is truely doing just headers and mating the stock cat-back to the headers, your giving up an X-pipe that you should get and about 15hp. 

Just my Opinion though, the guy at Jamison's is really the true expert.


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## Route 66 (May 30, 2005)

Cat backs are really not worth the money.... gains are very minimal.


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## jmd (Sep 29, 2006)

he is doing headers , x pipe and highflow cats all the way back to the mufflers. tks for the advise.


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## Route 66 (May 30, 2005)

Should sound awsome. What year is the car?


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## PapitoGTO (Aug 17, 2006)

The only restriction on the stock cat-back seems to be the mufflers, they are not a straight-thru design. An aftermarket cat-back will get rid off the kinks and dents on the pipes and on some will have a straight -thru design on the muffler section thus creating a faster exhaust flow (HP). Some claim more hp than others. But its up to your mods on your rides to create the hp. I personally chose a cat-back. But some people will just get the muffler section. Its up to you.


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## jmd (Sep 29, 2006)

it is a 2005 torrid red with lpe cai.


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## GTO DAN (Nov 16, 2006)

jmd said:


> it is a 2005 torrid red with lpe cai.


Go at least a cat-back with a true-x pipe and flowmaster, borla, corsa, JBA, etc... depending on what kind of sound you want. The gains are there on dyno day!! The stock GTO system is a disgrace! Uneven bends, kinks and dents so big it looks like a drunk mechanic did it with a pair of pliers and a hammer!! If you want to complete it, go with a set of headers (short or long, the difference is minimal unless you are high rpm and big cam) and a set of so-called high flow cat pipes.
If you want LOUD, try this... a friend with a 06 installed a true-x pipe and ran straight out the back through stock big tips.Almost 10hp on the dyno and the sweetest sound at 5,000 rpm you will ever hear!!  
On the GTO's, the exhaust does make a difference


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## stimeybob (Jan 10, 2007)

Get a CB, if your going to do any other mods you will need it.


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## Route 66 (May 30, 2005)

stimeybob said:


> Get a CB, if your going to do any other mods you will need it.


Ive done other mods. 421rwhp on only headers and stock exhaust. Why waste the money?


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## aintmisbehavinn (Feb 9, 2006)

Just take care of the kinks on the passenger side, throw on some strait thru 2 chamber flowmasters. Unless you plan on taking it apart, spend the money elsewhere.


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## jmd (Sep 29, 2006)

had arh 1 7/8 LT with crosspipe, highflow cat's and stock mufflers with dyno tune, got 370 rwh and 387 rwt with lpe cai. fast enough for me for now.


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## LYNMUP (Nov 26, 2005)

I had my stock mufflers cut off and had some 18" bullets installed in place. Noticed a big difference. Also have an X pipe but only a difference in sound since the resonator is a straight through design.

I wouldn't personally recommend buying an aftermarket catback cause I spent only $250 for my whole set-up and still got good power. Yes the stock pipes have some restriction but I don't think the extra $500 spent for the SLP loudmouth II would be worth it for maybe 1 or 2 hp. Sound I think is very much the same. That's my .02.


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