Catback Horsepower Increase?
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
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From: Minnesota
Catback Horsepower Increase?
I have read a number of posts stating that a aftermarket catback system does not increase horsepower and it is only for the sound.
Generally an aftermarket catback system is free-flowing compared to the stock system. How can it not increase the horsepower?
Does anyone have a before and after dyno proving there either is a HP increase or not?
Generally an aftermarket catback system is free-flowing compared to the stock system. How can it not increase the horsepower?
Does anyone have a before and after dyno proving there either is a HP increase or not?
Pro
Joined: Apr 2005
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From: Littleton NC
Intermediate
Joined: Nov 2006
Posts: 46
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From: England
A cat-back system may be freer flowing, but only beyond the cats. That ain't much use as far as your engine is concerned since most of the back pressure seen at the exhaust ports is caused by the restriction of the cats themselves.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
Race Director
Joined: Feb 2003
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From: ~The DARKSIDE Group~
A cat-back system may be freer flowing, but only beyond the cats. That ain't much use as far as your engine is concerned since most of the back pressure seen at the exhaust ports is caused by the restriction of the cats themselves.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
, well said
Le Mans Master
Joined: Nov 2005
Posts: 5,451
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From: East Peoria Illinois
A cat-back system may be freer flowing, but only beyond the cats. That ain't much use as far as your engine is concerned since most of the back pressure seen at the exhaust ports is caused by the restriction of the cats themselves.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
just did this last weekend..and
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Team Owner
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From: East Meadow NY
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A cat-back system may be freer flowing, but only beyond the cats. That ain't much use as far as your engine is concerned since most of the back pressure seen at the exhaust ports is caused by the restriction of the cats themselves.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
Installing free-flowing cats with long-tube headers and a tune will give a much better power increase because you're reducing the pressure throughout the system, not just at the far end of it.
Melting Slicks
Joined: Jan 2003
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From: Annapolis MD
I noticed a slight SOTP difference when I put on my Borlas... I recently had a tune (by Slohawk), and with JUST my Borlas and a Halltech (still haven't installed the LG LT's), I put down 337HP/328TQ SAE. That was with slightly fouled plugs too. Those are fairly big numbers for just intake/exhaust, but of course Slohawk is the tuning master. I can't WAIT to get my LT's on! So I think the answer is, it might be more than a neglible increase if you have it tuned afterward. I can't believe that I'd get over 30 more HP with JUST a tune and no mods...
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At near stock hp levels the gain is slim to none, it does make a difference once you are making big power though, Especially big cube N/A from what I have found.
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
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From: Minnesota
That does make sense. Kind of like a engine that uses forced induction. Normally insignificant changes on a stock N/A motor become very significant on the engine with forced induction.
Last edited by reactor2; Feb 27, 2007 at 01:32 PM.
Burning Brakes
Joined: Mar 2006
Posts: 1,195
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From: Tacoma WA
It would only really give HP gains if it were the bottleneck for exhaust flow. Odds are, it's not...
If you have a bored stroked, blown, engine w/ nitrous, 2" primaries, no cats, and 3.5" pipe all they back to a Stock Cat back... then yeah - replacing it will probably add 50 horsepower... But on a stock engine, replacing it will probably add nothing measurable...
Dan
If you have a bored stroked, blown, engine w/ nitrous, 2" primaries, no cats, and 3.5" pipe all they back to a Stock Cat back... then yeah - replacing it will probably add 50 horsepower... But on a stock engine, replacing it will probably add nothing measurable...
Dan
Burning Brakes
Joined: Feb 2005
Posts: 1,190
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From: Fayetteville AR
I read a thread today about a member that installed a different exhaust that I never heard of and he was happy with the SOTP results - look on todays/Monday posts and see if you can find it.
I researched this couple of years ago before I went with the Corsa Indy (loved the tips and the sound). Corsa emailed me that on the C5 they tested a 7 rwhp and 8 tq (not sure if that was with x pipe or not). I could not tell a difference after I installed it with the Corsa x pipe. And this was after I did the Vararam which I was hoping would make the car more efficient (I could feel the vararam – nice sotp).
I remembered looking at this fist link a while back so I thought I would share this with you.
http://www.vetteweb.com/tech/0501vet...mance_exhaust/
I found this one too and I was amazed at the result with just a Catback.
http://www.vetteweb.com/tech/0307vet...formance_info/
I would look into the Magnaflow it they can get this kind of returns. Heck I would be happy with just 12 HP.
I researched this couple of years ago before I went with the Corsa Indy (loved the tips and the sound). Corsa emailed me that on the C5 they tested a 7 rwhp and 8 tq (not sure if that was with x pipe or not). I could not tell a difference after I installed it with the Corsa x pipe. And this was after I did the Vararam which I was hoping would make the car more efficient (I could feel the vararam – nice sotp).
I remembered looking at this fist link a while back so I thought I would share this with you.
http://www.vetteweb.com/tech/0501vet...mance_exhaust/
I found this one too and I was amazed at the result with just a Catback.
http://www.vetteweb.com/tech/0307vet...formance_info/
I would look into the Magnaflow it they can get this kind of returns. Heck I would be happy with just 12 HP.
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The factory system actually is pretty good in terms of exhaust flow. I have a B&B system on mine and did not really feel any difference in how the car performed when I installed it - I did it mainly for the looks and sound.
Le Mans Master
Joined: Aug 2005
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From: FL
I didn't feel vararam, cats cut out, x pipe, catback, underdrive pulley
Only think I've felt was LT headers and I really felt those!
So if you're saying you didn't pick up any power because you didn't feel it that's wrong...it may add a few hp but that's not noticeable except for on a dyno.
Only think I've felt was LT headers and I really felt those!
So if you're saying you didn't pick up any power because you didn't feel it that's wrong...it may add a few hp but that's not noticeable except for on a dyno.
