Headers and Stock Mufflers?
Thread Starter
Pro
Joined: Jul 2005
Posts: 585
Likes: 0
From: Jacksonville FL
Headers and Stock Mufflers?
Is there a large performance loss by using stock pipes/LT1 mufflers and hiflow (or no) cats? Figuring a 400hp motor with headers and good flowing heads.
I like the idea of a quiet sleeper and I enjoy being able to hear the radio, but as Rickie Bobby says "I want to go fast"
I like the idea of a quiet sleeper and I enjoy being able to hear the radio, but as Rickie Bobby says "I want to go fast"
Pro
Joined: Oct 2009
Posts: 679
Likes: 0
From: vero beach florida
I have LT headers, bullit cats and stock cat back. I have to say that I don't think so. Heck, Corsa's catback system only give you 5hp over stock on a LT1.
I love the sound, car has no resonance and is just a little louder than stock at low rpms and then sounds mean when you step on the gas.
I love the sound, car has no resonance and is just a little louder than stock at low rpms and then sounds mean when you step on the gas.
Melting Slicks
Joined: Jan 2008
Posts: 2,054
Likes: 120
From: AZ
I have done it both ways, but in every case changed the whole system, so I won't comment on the rest.
Thread Starter
Pro
Joined: Jul 2005
Posts: 585
Likes: 0
From: Jacksonville FL
Thread Starter
Pro
Joined: Jul 2005
Posts: 585
Likes: 0
From: Jacksonville FL
Thank you very much for the info. Are you happy with the performance or would you go another route, if you were to do it again?
Do you have a recommendation on a good source for the cats you mentioned.
Thanks!
Do you have a recommendation on a good source for the cats you mentioned.
Thanks!
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Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
I'm not sold on a big performance increase for the dollar installing long tube headers on an LTx car. But, for me and many others is it just one piece of the puzzle.
Summit or Jegs should have decent prices on the PowerCats.
Summit or Jegs should have decent prices on the PowerCats.
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
LTHeaders and a good flowing muffler choice will help some with performance but the sound levels will increase. Quiet will not be the priority. Hedman makes good products for inexpensive headers but ceramic coated as suggested would be better for the long run. I bought a set from Exotic Muscle, they are almost double the price but will look great for years. The Vette stock exhaust flows pretty well except the stock manifolds until you start modding everything else. You will have tons of money invested to get to 400 hp.
Its been a while since Duval County had emmissions tests mandated by the EPA and without vehicle inspections you may get away without running cats. Problem would be finding a muffler shop that will do it for you. Some will if the car doesnt have cats on it when it rolls into the shop. I would not delete the connections for the cat in case you have to restore it back to standard. Get some "test pipes" to replace the cats. With all the industry in town, the EPA may be back at some point.
Its been a while since Duval County had emmissions tests mandated by the EPA and without vehicle inspections you may get away without running cats. Problem would be finding a muffler shop that will do it for you. Some will if the car doesnt have cats on it when it rolls into the shop. I would not delete the connections for the cat in case you have to restore it back to standard. Get some "test pipes" to replace the cats. With all the industry in town, the EPA may be back at some point.
Le Mans Master
Joined: Mar 2001
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
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St. Jude Donor '12
Well I'm shooting for a mild 300 - 330 rwhp with the minor top end changes I'm making.
Going to use Stainless works headers, cat and extensions to the stock mufflers cause I'm cheap. Got the headers, cats and extensions cheap, not paying more for a catback.
I don't anticipate the mufflers being a restriction. Maybe I'll disconnect them for one dyno run
Going to use Stainless works headers, cat and extensions to the stock mufflers cause I'm cheap. Got the headers, cats and extensions cheap, not paying more for a catback.
I don't anticipate the mufflers being a restriction. Maybe I'll disconnect them for one dyno run
Advanced
Joined: Feb 2009
Posts: 72
Likes: 0
I ran 390fwhp from my 383 LT4 with Hooker shortys + 100% stock rest of exhaust (cats, resonator and mufflers). So they flow at least that (I have stock heads). In future I will run with long tubes, small cats, stock resonator and muffler elims. When that is done, I take car to tune & dyno again. I hope I can hit over 410fwhp with that setup.
Last edited by Zoui; Jan 7, 2010 at 05:30 AM.
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
I have ran stock mufflers and magnaflow mufflers, both behind the long tube headers, at the track, I cant tell any difference. But I dont have dyno results both ways.
BTW the car is the first one in my signature. And my best times were run on stock mufflers.
BTW the car is the first one in my signature. And my best times were run on stock mufflers.
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
It is quieter, but not as quiet as I thought it would be. I have tried both. I eliminated the cats and left the resonator in place, then I eliminated the resonator and put 2 bullet cats in where the resonator was. The ones I used come from pyles. They were $69.00 each.