C4 Frame braces
Race Director
Joined: Mar 1999
Posts: 12,597
Likes: 237
From: Bartlett Illinois
Melting Slicks
Joined: Feb 2005
Posts: 3,204
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From: Midland Georgia
St. Jude Donor '06
These are nice and I can see that they would help by firming it up but the cost is currently too high for most of us.
I bought a used Cross Frame for $200 awhile back. I installed it but ran into exhaust clearance issues. Then along came the rear suspension/clutch project. The car is going back together now and I will have to sort out the Cross Frame fitment with my exhaust. This dang Cross Frame weighs a ton and it is counter intuitive to keep adding weight to "fix" C4 problems. If they had done this at the factory these cars would have ended up weighing in at 4000lbs!
Here is a shortcut to the Frame Brace.
http://www.vettextc.net/MY_ZR-1/Frame_Brace_GP.html
I bought a used Cross Frame for $200 awhile back. I installed it but ran into exhaust clearance issues. Then along came the rear suspension/clutch project. The car is going back together now and I will have to sort out the Cross Frame fitment with my exhaust. This dang Cross Frame weighs a ton and it is counter intuitive to keep adding weight to "fix" C4 problems. If they had done this at the factory these cars would have ended up weighing in at 4000lbs!
Here is a shortcut to the Frame Brace.
http://www.vettextc.net/MY_ZR-1/Frame_Brace_GP.html
Last edited by jakers; Jul 7, 2010 at 02:51 PM.
Thread Starter
Race Director
Joined: Feb 2003
Posts: 16,475
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From: Kingman AZ
Cruise-In VII Veteran
Cruise-In VIII
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
I have been driving my 91 coupe with the hatch roof removed and can really feel a difference.
The car feels as if I just drove it off the showroom floor. I can drive over railroad tracks without slowing down to 10 mph. I can take the curves on my local "Corvette therapy" twisty road much faster. The car feels completely different to me. I am real happy with the setup. No more rattles either!
She is temporarily out of service as I am replacing most of the exhaust system along with modding the intake system to include new Bosch IIIs from FIC injectors.
The car feels as if I just drove it off the showroom floor. I can drive over railroad tracks without slowing down to 10 mph. I can take the curves on my local "Corvette therapy" twisty road much faster. The car feels completely different to me. I am real happy with the setup. No more rattles either!
She is temporarily out of service as I am replacing most of the exhaust system along with modding the intake system to include new Bosch IIIs from FIC injectors.
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Team Owner
Joined: Dec 2007
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These are nice and I can see that they would help by firming it up but the cost is currently too high for most of us.
I bought a used Cross Frame for $200 awhile back. I installed it but ran into exhaust clearance issues. Then along came the rear suspension/clutch project. The car is going back together now and I will have to sort out the Cross Frame fitment with my exhaust. This dang Cross Frame weighs a ton and it is counter intuitive to keep adding weight to "fix" C4 problems. If they had done this at the factory these cars would have ended up weighing in at 4000lbs!
Here is a shortcut to the Frame Brace.
http://www.vettextc.net/MY_ZR-1/Frame_Brace_GP.html
I bought a used Cross Frame for $200 awhile back. I installed it but ran into exhaust clearance issues. Then along came the rear suspension/clutch project. The car is going back together now and I will have to sort out the Cross Frame fitment with my exhaust. This dang Cross Frame weighs a ton and it is counter intuitive to keep adding weight to "fix" C4 problems. If they had done this at the factory these cars would have ended up weighing in at 4000lbs!
Here is a shortcut to the Frame Brace.
http://www.vettextc.net/MY_ZR-1/Frame_Brace_GP.html
I'd be happy to trade you a light GM brace for you big heavy R&D brace.
Team Owner
Joined: Aug 2005
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From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09 thru '20
Racer
Joined: Jul 2005
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From: Arlington Texas
Drifting
Joined: Jan 2007
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From: Supreme Soviet Peace-Loving Pipple's Kollektive of Seattle Wa
Race Director
Joined: Mar 1999
Posts: 12,597
Likes: 237
From: Bartlett Illinois
According to Gordon you need to adjust the bars to get them right. I think I have them right, the car is tight, with the top off, much better then when they were first installed. I think I could adjust the driver side again maybe
Speculate all you want about these, as far as I am concerned these work and work well..
Speculate all you want about these, as far as I am concerned these work and work well..
Racer
Joined: May 2010
Posts: 315
Likes: 0
From: Central New York NY
I've been reading this thread with interest since my 85 really loosens up with the top off. It would seem to me that the rods might bow the frame in a slight upward direction to counteract frame sag. After all, the windshield frame and the rear hoop can't move towards each other when the roof is in place. When the roof is off, the frame can sag in the middle and when the front end goes over bumps it can flex even more. I would be curious to find out whether the rods get adjusted with the roof on or off. The removal of the sag by the rods could probably be measured if it was setup carefully enough.
Advanced
Joined: Jun 2010
Posts: 91
Likes: 1
From: Raleigh NC
I have been driving my 91 coupe with the hatch roof removed and can really feel a difference.
The car feels as if I just drove it off the showroom floor. I can drive over railroad tracks without slowing down to 10 mph. I can take the curves on my local "Corvette therapy" twisty road much faster. The car feels completely different to me. I am real happy with the setup. No more rattles either!
She is temporarily out of service as I am replacing most of the exhaust system along with modding the intake system to include new Bosch IIIs from FIC injectors.
The car feels as if I just drove it off the showroom floor. I can drive over railroad tracks without slowing down to 10 mph. I can take the curves on my local "Corvette therapy" twisty road much faster. The car feels completely different to me. I am real happy with the setup. No more rattles either!
She is temporarily out of service as I am replacing most of the exhaust system along with modding the intake system to include new Bosch IIIs from FIC injectors.
Race Director
Joined: Mar 1999
Posts: 12,597
Likes: 237
From: Bartlett Illinois
I've been reading this thread with interest since my 85 really loosens up with the top off. It would seem to me that the rods might bow the frame in a slight upward direction to counteract frame sag. After all, the windshield frame and the rear hoop can't move towards each other when the roof is in place. When the roof is off, the frame can sag in the middle and when the front end goes over bumps it can flex even more. I would be curious to find out whether the rods get adjusted with the roof on or off. The removal of the sag by the rods could probably be measured if it was setup carefully enough.
roof is on and hood and doors are closed as well..
Thread Starter
Race Director
Joined: Feb 2003
Posts: 16,475
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From: Kingman AZ
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Cruise-In VIII
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
Advanced
Joined: Jun 2010
Posts: 91
Likes: 1
From: Raleigh NC
Any ideas how this device ( Targa Truss ) compares to the Frame Brace? It's a few hundred cheaper but it attacks the issue from the top vs. the bottom and I would hate to waste my money.
http://r-dracing.com/targa-truss.htm
http://r-dracing.com/targa-truss.htm
