Stock Headers vs Aftermarket Headers
Thread Starter
Instructor
Joined: Sep 2005
Posts: 144
Likes: 1
From: Collierville TN
Stock Headers vs Aftermarket Headers
I have been searching through the forum for aboput an hour trying to nail down a good set of headers to buy. 
A guy I work with came in and asked why I was looking for headers when my car already had them?????? Damn good question I said.
I have the original headers in the old 1980 L-48.
Question #1 - How much more horsepower could I expect to benefit from switching to an aftermarket set of headers?
Question #2 - Does anyone have suggestions on replacement set?
A guy I work with came in and asked why I was looking for headers when my car already had them?????? Damn good question I said.
I have the original headers in the old 1980 L-48.
Question #1 - How much more horsepower could I expect to benefit from switching to an aftermarket set of headers?
Question #2 - Does anyone have suggestions on replacement set?
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Those are the old stock iron manifolds! I've got a set sitting in my garage just like em. The AIR crap on top really makes them craptastic, in my opinion. If you want a good set of inexpensive long tube headers you can get a set for $75 at summit racing. 
Others will chime in with their suggestions, though.
Drifting
Joined: Nov 2004
Posts: 1,971
Likes: 7
From: Longwood Florida
those manifolds/factory headers are only just a little better than the ramhorns... and from what I have been told the ramhorns flow decent for factory manifolds.
With a stock motor, small tube long tubes are the best... gives you more low end torque.
If you have aftermarket cam and heads... go with the big tube coated headers... long tube again...
don't forget to take off the SMOG crap...
UNLESS IT IS ILLEGAL in your area....
With a stock motor, small tube long tubes are the best... gives you more low end torque.
If you have aftermarket cam and heads... go with the big tube coated headers... long tube again...
don't forget to take off the SMOG crap...
UNLESS IT IS ILLEGAL in your area....
Drifting
Joined: Feb 2005
Posts: 1,738
Likes: 2
From: San diego ca
those factory headers have like 1 1/4 or 1 1/2" primaries... and a 2 1/2" collector... which means as far as headers go they make great doorstops.
Unless you are really planning on building some high HP numbers (like in excess of 400 or so) then anything bigger than 1 5/8" primaries will be a waste...
Get a set of 4-1 long tube headers from dynomax or hedman.. 1 5/8" primaries and 3" collector... and you will be very happy
Actually those are the mild steel headers that came on the later model C3's and carried into the 4th gen cars (eventually stainless steel).
Unless you are really planning on building some high HP numbers (like in excess of 400 or so) then anything bigger than 1 5/8" primaries will be a waste...
Get a set of 4-1 long tube headers from dynomax or hedman.. 1 5/8" primaries and 3" collector... and you will be very happy
Those are the old stock iron manifolds! I've got a set sitting in my garage just like em
Last edited by fauxrs2; Jul 6, 2006 at 08:24 PM.
Thread Starter
Instructor
Joined: Sep 2005
Posts: 144
Likes: 1
From: Collierville TN
Tuned or Not Tuned is now the question
those factory headers have like 1 1/4 or 1 1/2" primaries... and a 2 1/2" collector... which means as far as headers go they make great doorstops.
Unless you are really planning on building some high HP numbers (like in excess of 400 or so) then anything bigger than 1 5/8" primaries will be a waste...
Get a set of 4-1 long tube headers from dynomax or hedman.. 1 5/8" primaries and 3" collector... and you will be very happy
Unless you are really planning on building some high HP numbers (like in excess of 400 or so) then anything bigger than 1 5/8" primaries will be a waste...
Get a set of 4-1 long tube headers from dynomax or hedman.. 1 5/8" primaries and 3" collector... and you will be very happy
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Drifting
Joined: Feb 2005
Posts: 1,738
Likes: 2
From: San diego ca
Originally Posted by rrhodes4
Should I be concerned about whether or not they are tuned???
You get what you get with mass-produced headers...any tuning done is most likely tuning performed by the marketing department IMO YMMV we arent talking 180 deg. headers here. About the only tuning that can be done is to try to ensure that the tubes are equal length...Hedmans are not equal length best i can tell...dynomax might be....they both probably claim to be equal length
Last edited by fauxrs2; Jul 7, 2006 at 10:57 AM.
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
Long tubes of the wrong length are inherantly as useful as short tubes. Just like equal length of the wrong length is also about as useful as short tube headers of the wrong length. Long tube headers to be useful requires extensive dyno tuning to find the scavenging point and then you have the right length secondary. And if your motor is never going to see above 5500 rpm, long tubes are of dubious value anyway over say a short tube or a tri-Y. To get your headers to be all they can be and get actual value out of the long tube requires a lot of money and testing for your specific RPM range. So buy what you can afford and get something in the 1.625" primary range and a 3" secondary.
Hedman makes some affordable headers, but make sure you get a muffler and exhaust system that can handle the flow. Also you can tune your secondaries for even more scanvenging than you can your primaries. Its a complicated affair.
Hedman makes some affordable headers, but make sure you get a muffler and exhaust system that can handle the flow. Also you can tune your secondaries for even more scanvenging than you can your primaries. Its a complicated affair.
Last edited by Guru_4_hire; Jul 7, 2006 at 05:45 PM.
