Floor Pan and Open Hooker Headers Question
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Pro
Joined: May 2000
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From: Midland Texas
St. Jude Donor '09-'11
Floor Pan and Open Hooker Headers Question
I put Hooker 1-7/8" inside the frame equal length headers on our 427 '66 Vette but have not run them open yet. The collector is just ahead of the trans crossmember and just below the fiberglass floor.
Is it necessary to add a heat shield on the floor pan to keep exhaust heat from an open exhaust from damaging the fiberglass? If so, how should the shield be fabricated and attached?
This is a drag race application not road race, so I may be concerned over nothing, but I would rather risk asking a silly question than repairing fiberglass.
Joe Lynch
Midland, TX
Is it necessary to add a heat shield on the floor pan to keep exhaust heat from an open exhaust from damaging the fiberglass? If so, how should the shield be fabricated and attached?
This is a drag race application not road race, so I may be concerned over nothing, but I would rather risk asking a silly question than repairing fiberglass.
Joe Lynch
Midland, TX
Melting Slicks
Joined: Jun 2001
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From: Moro IL
Re: Floor Pan and Open Hooker Headers Question (Joe Lynch)
Well I don't know if this is of any help or not, but I drove mine to the exhaust shop open headers for about an 8 mile distance (had to go the back roads to avoid the police) and i didn't notice any excessive heat from the floorboards, but I'd say a heat shield probably wouldn't be a bad idea just in case.
:cheers:
Pat Kunz
:cheers:
Pat Kunz
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Re: Floor Pan and Open Hooker Headers Question (Joe Lynch)
Why not have a muffler shop make you some 2 foot pipes that'll bolt up to the header flange, and exit in front of the rear tires, under the doors?
That's what I plan to do for when I hit the track (I have cats on mine for street running).
That way, you can avoid the possibility of the heat damaging the 'glass, and not have to go through modifying your undercarriage.
I have a small section that runs from the header flange to just in front of the x-member, when I get to the track, I'll remove the small section, and bolt in the 3 inch pipes like I described, leaving the rest of the exhaust in place. When I'm through, I'll just toss the open pipes in the rear, and replace the section to the 'street' exhaust for the ride home.
That's what I plan to do for when I hit the track (I have cats on mine for street running).
That way, you can avoid the possibility of the heat damaging the 'glass, and not have to go through modifying your undercarriage.
I have a small section that runs from the header flange to just in front of the x-member, when I get to the track, I'll remove the small section, and bolt in the 3 inch pipes like I described, leaving the rest of the exhaust in place. When I'm through, I'll just toss the open pipes in the rear, and replace the section to the 'street' exhaust for the ride home.
Thread Starter
Pro
Joined: May 2000
Posts: 610
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From: Midland Texas
St. Jude Donor '09-'11
Re: Floor Pan and Open Hooker Headers Question ('75 383 ElkGrove)
I think I can build a new transition piece between the header and the cross member using a 15" long x3" diameter straight header collector extension with a cap on the rear end, then just merge the exhaust pipe section into the side. Just like we did it in the 60s, LOL. Here are some pictures.
http://www.lx.net/jlynch/vetdumpfront.jpg
http://www.lx.net/jlynch/vetdumprear.jpg
This way, we can just uncap the dumps at the strip without having to fool with the transition piece and slip joint at the crossmember. I also found some heat shield material in Jeg's catalog that can be attached to the bottom of the floor pan to protect it, but I don't think it is really a concern now that I have gotten to look at the clearances.
http://www.lx.net/jlynch/vetdumpfront.jpg
http://www.lx.net/jlynch/vetdumprear.jpg
This way, we can just uncap the dumps at the strip without having to fool with the transition piece and slip joint at the crossmember. I also found some heat shield material in Jeg's catalog that can be attached to the bottom of the floor pan to protect it, but I don't think it is really a concern now that I have gotten to look at the clearances.
Le Mans Master
Joined: Apr 2000
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From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Re: Floor Pan and Open Hooker Headers Question (Joe Lynch)
You could wrap the headers with an insulating fiberglass wrap to keep the actual header temp down, but that won't help with the exhaust :( . If your only running the car at the track to go down an 1/8 or 1/4 mile you may be ok. Go to the track and see if anyone else is running open headers on a Vette and if they've had any problems.
