Mystery Wagon Frame Braces?
#1
Mystery Wagon Frame Braces?
Hello everyone, I remember seeing in the Oldsmobile Chassis Service Manual pictures of front frame braces used on the Cutlass wagons for 70-72. Has anyone ever seen these on the cars? Just always wondered about that. Thanks
#2
If you are talking about the diagonal cowl braces used on the Vista Cruisers, yeah, every 1970-72 Vista came with them. Note that the page from the PIM says "4800 only", which is the Vista Cruiser model designation.
#3
#4
I am aware of the upper fender braces, seen them before. I remember seeing lower braces attached to the frame in the front of the car, also not the rear frame braces on some four speed cars. Thanks
#10
Just curious about the frames in the first picture, my Vista has them and the drive side brace interferes with battery maintenance/removal although minor. My question is this, why are the necessary?
#12
I will be interested in Joe's take. Mr. Structural Engineer always gives us a logical explanation.
Gary
#13
My thought is that the longer wheelbase of the Vista, coupled with the higher probability that the wagon would be actually used as a wagon (hauling stuff), led to the use of those diagonal braces to stiffen the front end against a torsional mode. Frankly those struts aren't particularly structural. More likely they are there to raise the natural frequency in torsion to avoid a suspension mode that might hit resonance and cause an NVH issue.
#14
I think I’ve asked this before, but while we’re on topic of firewall / fender / radiator support braces…
Is there any point in adding them to my ‘66 big cars? My ‘66 98 convertible shakes a bit on the freeway, I’ve been curious for years as to whether braces might help that. I’m not too optimistic though, since convertibles are, well, a structural compromise. And really, how much could a couple of 1/2” or 3/4” tubes really reduce shake?
Hypothetically, if I were to brace the radiator support or fenders to the firewall I’d put a support piece on the firewall to thicken it a bit, but it’s probably all for nought.
It’s just that I’ve observed braces in C*ddies and other GM’s of similar & later vintages and wondered whether adding them could do me some good.
Joe P, if you choose to indulge me, many thanks. I believe you’ve weighed in in the negative before. And I have every reason to trust a structural engineer on these points.
Cheers
cf
Is there any point in adding them to my ‘66 big cars? My ‘66 98 convertible shakes a bit on the freeway, I’ve been curious for years as to whether braces might help that. I’m not too optimistic though, since convertibles are, well, a structural compromise. And really, how much could a couple of 1/2” or 3/4” tubes really reduce shake?
Hypothetically, if I were to brace the radiator support or fenders to the firewall I’d put a support piece on the firewall to thicken it a bit, but it’s probably all for nought.
It’s just that I’ve observed braces in C*ddies and other GM’s of similar & later vintages and wondered whether adding them could do me some good.
Joe P, if you choose to indulge me, many thanks. I believe you’ve weighed in in the negative before. And I have every reason to trust a structural engineer on these points.
Cheers
cf
#15
My thought is that the longer wheelbase of the Vista, coupled with the higher probability that the wagon would be actually used as a wagon (hauling stuff), led to the use of those diagonal braces to stiffen the front end against a torsional mode. Frankly those struts aren't particularly structural. More likely they are there to raise the natural frequency in torsion to avoid a suspension mode that might hit resonance and cause an NVH issue.
#16
This is especially true when you remember that the attachment of the core support to the frame is rubber bushings, so these do exactly nothing structurally. Non-structural engineers frequently don't understand the difference between stiffness and strength. Glass is stiff but not strong (usually). A willow is strong but not stiff.
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