Why do people change out headers?
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Pro
Joined: Jan 2008
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From: Kyle TX
Why do people change out headers?
I know they do it for more HP. However wouldn't the engineers that designed the Corvette, design it with the best headers for the car? The same thing for exhaust and cai?
Just wondering.
Just wondering.
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Racer
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From: Clayton NC
Does any mass produced factory car actually use real headers? I have only seen normal exhaust manifolds, usually cast, used for factory cars. Headers are a bunch of tubes vs a manifold that is a much more inefficient design.
Melting Slicks
Joined: Oct 2007
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From: Northwestern Connecticut
St. Jude Donor '10 thru '26
Cast manifolds are cheapest and less prone to have gasket leaks. (Less warranty work). They are also quieter. But they are no where near as efficient as headers. The ls7 exhaust manifold is a bit different, more efficient, so the gains there are not as great as with the ls3. But once the ls7 is modified (cam etc) even it gains pretty good with headers.
it's more, not less.
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Like someone said, for legal purposes. Noise, fuel efficiency, cost,longevity, etc.
Theres always more power to be had on any car.
Doing long tubes on my car was the best thing I did. I can't see how anyone can drive a vette on stock manifolds. My car was stock without the npp and I drove it like that for about a month and I was going nuts. There was no feedback. Felt like I was driving a manual Prius lol.
Then long tubes, no cats and a borla exhaust and its like all hell breaks loose each time I step on the throttle lol. I love it.
Theres always more power to be had on any car.
Doing long tubes on my car was the best thing I did. I can't see how anyone can drive a vette on stock manifolds. My car was stock without the npp and I drove it like that for about a month and I was going nuts. There was no feedback. Felt like I was driving a manual Prius lol.
Then long tubes, no cats and a borla exhaust and its like all hell breaks loose each time I step on the throttle lol. I love it.
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What headers do,
The down side, more noise, and the huge problem, it moves the Cats so far down line that they become less effective.
On the Zo6, it uses OEM shorter headers some what, which give a gain of around 15hp over cast manifolds, while the long tube headers end up with around a 25 to 30hp gain over the cast manifolds instead (better collector design over just longer tubes to be scavenged alone instead.
As for why all Vets don't have the oem shorter headers, it's called value engineering to keep the construction costs down on the lesser models like the base units, since the OEM cast manifold are much cheaper to make instead (and have very little scavenging effect instead).
To note, its not just the shorter headers on the LS-7 that holds back HP, but the size of the intake runners on the intake manifold as well. So the battle on the LS-7 to unleash it, it not to just install LT headers, but get a intake manifold on the motor that will allow it to breath correctly at top RPM's as well (and still fit under the hood as well).
So at the 504HP rating, it due to the motor being crippled, and not hard to end get an additional 60HP on the base motor with a tune, headers, and an intake manifold that will allow the engine to breath correctly at top RPM instead.
The down side, more noise, and the huge problem, it moves the Cats so far down line that they become less effective.
On the Zo6, it uses OEM shorter headers some what, which give a gain of around 15hp over cast manifolds, while the long tube headers end up with around a 25 to 30hp gain over the cast manifolds instead (better collector design over just longer tubes to be scavenged alone instead.
As for why all Vets don't have the oem shorter headers, it's called value engineering to keep the construction costs down on the lesser models like the base units, since the OEM cast manifold are much cheaper to make instead (and have very little scavenging effect instead).
To note, its not just the shorter headers on the LS-7 that holds back HP, but the size of the intake runners on the intake manifold as well. So the battle on the LS-7 to unleash it, it not to just install LT headers, but get a intake manifold on the motor that will allow it to breath correctly at top RPM's as well (and still fit under the hood as well).
So at the 504HP rating, it due to the motor being crippled, and not hard to end get an additional 60HP on the base motor with a tune, headers, and an intake manifold that will allow the engine to breath correctly at top RPM instead.
Last edited by Dano523; Oct 3, 2015 at 03:49 PM.
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