Frame/A Arm failure
10-06-2014, 12:23 PM
#21
Race Director
BeeJay... Danny and Chris can fix this for you.... they just finished a $60K baja build for Daric Colman of the Seattle SeaHawks.. Full custom race suspension.
and they can make it much stronger as well...
and they can make it much stronger as well...
10-06-2014, 04:50 PM
#22
Burning Brakes
My 73 A-arm attachment looked similiar- spooked me to think of the potential failure. After viewing the "quality" of the GM factory welds, I had no reservations about welding it my self at home! I fortified the frame with the Power Manual recommendations too
10-06-2014, 10:42 PM
#23
Melting Slicks
Member Since: May 2002
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St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19
Norval talked about this years back and had some pics of his mods to strengthen this area.
You may still be able to do a search and find the threads, if your lucky he will still have the pics hosted.
Neal
You may still be able to do a search and find the threads, if your lucky he will still have the pics hosted.
Neal
10-06-2014, 10:52 PM
#24
Pro
There is some pictures of those Corvette Racing Manual reinforcements added to my frame in my "garage".
https://www.corvetteforum.com/g/album/1302411
In addition one should complete (weld 100%) the pointwelds holding the front crossmember topside to the bottom side (clearly seen in the first post in this thread.
There is a LOT of force on the trailingarms when braking hard during inspired driving. Especially when one have big brakes and sticky tires..
https://www.corvetteforum.com/g/album/1302411
In addition one should complete (weld 100%) the pointwelds holding the front crossmember topside to the bottom side (clearly seen in the first post in this thread.
There is a LOT of force on the trailingarms when braking hard during inspired driving. Especially when one have big brakes and sticky tires..
Last edited by RickyBerg; 10-06-2014 at 10:56 PM.
10-07-2014, 12:52 AM
#26
Pro
Is it time for a new frame? To do the repairs I think you'll need to have the body out of the way and probably the engine/transmission out as well. If you had a new frame from someplace like Collier with C4/5/6 suspension points you could have aluminum suspension components, rack & pinion steering etc. You could have the rolling chassis ready to swap in a long weekend. Think of the weight savings -- all those aluminum parts and a really lightweight wallet. Just a thought...
10-09-2014, 11:37 PM
#27
Burning Brakes
Bee Jay,
I intend to run in an autoccross for the first time in my '78. It's modified similar to yours. In which class do you run? I' guessing my car fits in SSM. I will be under the car this weekend inspecting the frame!
I intend to run in an autoccross for the first time in my '78. It's modified similar to yours. In which class do you run? I' guessing my car fits in SSM. I will be under the car this weekend inspecting the frame!
10-10-2014, 04:53 PM
#28
Safety Car
Member Since: May 2004
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Did you happen to tighten the lower control arm bushings when the front end was suspended in the air instead of with the front end loaded down on the ground after settling in?
If you had tightened the lower bushing while the front end was suspended in the air you would have imputed a preload on the bushings for when the car was lowered and if the lower control arm bumpers are missing then you could really over turn the bushing on compression travel?
If you had tightened the lower bushing while the front end was suspended in the air you would have imputed a preload on the bushings for when the car was lowered and if the lower control arm bumpers are missing then you could really over turn the bushing on compression travel?
10-10-2014, 07:05 PM
#29
Drifting
Damn-and you car is pretty light too I'll bet it would have failed much sooner if you hadn't done all the weight reduction mods.
10-12-2014, 01:19 AM
#30
Le Mans Master
fourth picture sshows that the upper side of the crossmember is torn as well.
I'd say its time for a motor pull and maybe even a body off.
And do a bunch of gusseting and repairs
I'd say its time for a motor pull and maybe even a body off.
And do a bunch of gusseting and repairs
10-13-2014, 09:43 AM
#31
Team Owner
I don't think that you could put enough shims to bring the alignment back
My 79 cracked the frame near the rear lower a-arm rear crossbar bolt on the same passenger side as yours. I caught it early when I had it up on a lift getting ready to do a front end alignment. I attributed my problem to 700# front springs and 295 width front road racing slicks, and poly a-arm bushings. With all that TQ the frame gave up. Yours has probably been cracked for quite some time and it kept getting bigger until you had catastrophic failure
I was able to weld, fish plate, and gusset the area on both sides.
A body shop with a framing machine could probably pull it all back into place and then cut out the bad and make it stronger than the original. Or compare it price wise of going to that recent post of the super tube frame setup
My 79 cracked the frame near the rear lower a-arm rear crossbar bolt on the same passenger side as yours. I caught it early when I had it up on a lift getting ready to do a front end alignment. I attributed my problem to 700# front springs and 295 width front road racing slicks, and poly a-arm bushings. With all that TQ the frame gave up. Yours has probably been cracked for quite some time and it kept getting bigger until you had catastrophic failure
I was able to weld, fish plate, and gusset the area on both sides.
A body shop with a framing machine could probably pull it all back into place and then cut out the bad and make it stronger than the original. Or compare it price wise of going to that recent post of the super tube frame setup
10-13-2014, 10:35 AM
#32
Team Owner
I have heard/read that the later shark frames were lighter/thinner steel than the early ones....and my pro welder buddy could fix that fairly easy right there in his garage, complete with added gussets and more welding....I just looked at my '72 frame which has had the cross support on it for years now, and it looks fine, I have '89 vette wheels/50 series tires on it and drive quickly, but it's all street driving, hardly a track car.....
10-21-2014, 11:47 AM
#33
Melting Slicks
Member Since: Feb 2001
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Hi
I got told that this brace will eliminate such cracks, but now stand corrected ! The brace eliminatse front crossmember bending during driving. It bends a lot because it is not straight.
May be it was already cracked when the brace was installed ?
Rgds. Günther
just a question, do you have a brace running between the upper control arms?
May be it was already cracked when the brace was installed ?
Rgds. Günther
10-21-2014, 03:56 PM
#34
Instructor
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10-21-2014, 04:07 PM
#35
Le Mans Master
10-22-2014, 02:28 AM
#36
Pro
10-22-2014, 02:44 AM
#37
Pro
The recommendations below are (in my opinion) the least one should do to the frame before adding a HP Engine, HP brakes and wide sticky tires.
To me it is not surprising that a 40 year old production car made to cruise the streets on those tires of the era suddenly decides to give in after been driven hard on a race track.
To me it is not surprising that a 40 year old production car made to cruise the streets on those tires of the era suddenly decides to give in after been driven hard on a race track.