Headers,heat,noise,and 5%psychosomatic hp-torque

dave lowry

New member
Jul 7, 1998
615
0
0
>In resent diagnostic tests on a 455 on stand first with regular manifolds
>then with headers from low to high rpm the increase across the chart was only
>5%. [these tests were made by a shop that builds $100,000 NASCAR engines and
>is pro headers] My question is it worth it? I have seen a GMC with headers
>that actually melted the wheel cover also one that burned up the starter and
>other wires.not only that the fire danger is much greater.Also it increases
>the heat thru the floor while driving and after you stop. Noise increase is
>terriable.Many times when you remove them they can warp and will not bolt
>back up tight again. I know most the arguments about all the power but can
>you really feel 5%? I was in the auto exhaust business for over 35 years with
>5 shops sold and installed not hundreds but thousands of headers and with
>every set I tried to talk the customer out of it but they were all sure they
>knew a lot more me. Maybe that helped sales I don't know but after spending
>all that money and you would ask them how it ran guess what they would say to
>me and there friends. O man the power! If someone would offer me a trip to
>Hawaii along with Julia Roberts and Sharon Stone I still would not let them
>install headers on my GMC. I hope I have not started a few pages of NET-RAGE
>and I hope maybe someone out there mite even agree with me. I'll guess not,
>and yes there are some things you can do to improve the exhaust on a GMC
>motorhome but headers should not be one of them. Jim Anstett Loveland
>Colorado

Jim, I'll not argue, and I hope there's no flames from your statement. I
am, however, very interested in those things your experience dictates can
be done to improve our GMC's exhaust.

Listening........

Dave (advisor/navigator) & Dege (ALL else), '76 Royale, Santa Barbara, CA
 
Jim,
I always agree with you and especially like the A/C modifications you've
made, however, we part ways on headers. 1. Properly installed headers do
not melt wheel covers or hurt starters or wiring in any way. How many cast
iron manifold equipped GMC's have burned? Anecdotal evidence of these being
a fire hazard is very suspect and have more in common with Urban Legends
than with facts. 2. They don't warp as bad as cast iron. 3. Mine are
quieter than the old cast iron junk. Now the noisiest thing is the air
conditioning blower.
I tried to fix the cast iron manifolds for 10 years. I had them planed
twice and tried every conceivable combination of gaskets and high
temperature cement. Every six months they were leaking again. I finally
gave up and went to headers. Now I even get 5% more power and 4 years of
quiet.
Please don't take this as NET-RAGE. I'd still like some of your famous
'lemonade'.
Bob McLaughlin
- -----Original Message-----
From: owner-gmcmotorhome
[mailto:owner-gmcmotorhome]On Behalf Of
JKAnstett
Sent: Monday, May 29, 2000 5:29 PM
To: gmcmotorhome
Subject: GMC: Headers,heat,noise,and 5%psychosomatic hp-torque

In resent diagnostic tests on a 455 on stand first with regular manifolds
then with headers from low to high rpm the increase across the chart was
only
5%. [these tests were made by a shop that builds $100,000 NASCAR engines and
is pro headers] My question is it worth it? I have seen a GMC with headers
that actually melted the wheel cover also one that burned up the starter and
other wires.not only that the fire danger is much greater.Also it increases
the heat thru the floor while driving and after you stop. Noise increase is
terriable.Many times when you remove them they can warp and will not bolt
back up tight again. I know most the arguments about all the power but can
you really feel 5%? I was in the auto exhaust business for over 35 years
with
5 shops sold and installed not hundreds but thousands of headers and with
every set I tried to talk the customer out of it but they were all sure they
knew a lot more me. Maybe that helped sales I don't know but after spending
all that money and you would ask them how it ran guess what they would say
to
me and there friends. O man the power! If someone would offer me a trip to
Hawaii along with Julia Roberts and Sharon Stone I still would not let them
install headers on my GMC. I hope I have not started a few pages of NET-RAGE
and I hope maybe someone out there mite even agree with me. I'll guess not,
and yes there are some things you can do to improve the exhaust on a GMC
motorhome but headers should not be one of them. Jim Anstett
Loveland
Colorado