C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Camber Brace

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Old 03-30-2005, 02:05 PM
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loiq
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Default Camber Brace

I was wondering if anyone has any test data that shows before and after performance improvements from installing the R-D Racing Camber Brace.
Old 03-30-2005, 02:47 PM
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luvmy92
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Not a true test but I picked up 6 seconds at Sebring (from 2:38 to 2:32), but had also picked up 6 seconds the time before as well. The seconds will be tougher to come by now but there is still a little bit left in her.

However, the car definitely feels tighter with the camber brace. I like it alot.

Mike
Old 03-30-2005, 03:15 PM
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Strick
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I wish I could show you the difference in the tire patch in a hard turn before and after the camber-brace install. Somebody on here has a few pictures showing exactly what it does for you. I can say it gives you a more precise feel of your Vette in a turn. This with the cross-bar, has made my vert as stiff or stiffer as any coupe with the top in.
Old 03-30-2005, 03:31 PM
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Gary04Z06
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No real test, but, I ran an autox without it, then the next weekend ran the same track layout and had better times. I suppose a number of things could have changed to make improved times. But, the car felt better in the turns.
Old 03-30-2005, 03:56 PM
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Wheelman
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Did you read Dave's reply in the other thread you posted in? It explains exactly how it helps your performance.
If you look at the frame of your car, you’ll see that the frame rails forward of the firewall are smaller than they are going toward the rear. The Upper control arms mount to the front cross member which drops over a foot before going to the other side. The fact that the frame members are so small; they do not support the weight without flexing. When the cross member flexes, your alignment settings change which gives the car it’s darty feeling going down the road. The Camber-brace boxes in the cross member and prevents this flex, allowing the alignment settings to be maintained. If you would like to perform a simple test to prove this to yourself, you can measure the distance between the frame horns, then place a jack in the middle of the cross member and jack up the car. Then re-measure the distance again. I've seen C4's that will flex close to an 1/2" by doing this.
The flex he is talking about affects camber. The upper control arms flex in and the top of the tire will flex in with it a bit as a result. To much camber and you lose part of your contact patch on the road under hard cornering. Need I explain what happens when you reduce your contact patch as well?
Old 03-30-2005, 04:10 PM
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4GTWRK
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Originally Posted by Wheelman
Did you read Dave's reply in the other thread you posted in? It explains exactly how it helps your performance.

The flex he is talking about affects camber. The upper control arms flex in and the top of the tire will flex in with it a bit as a result. To much camber and you lose part of your contact patch on the road under hard cornering. Need I explain what happens when you reduce your contact patch as well?

Even worse, they flex outward and you loose the negative camber that your trying to achieve for harder cornering. If you’ve ever gotten into a corner and felt your tires chattering, you will know what I’m talking about. The chattering is the result of frame flex and your camber going positive. With the Camber-brace, your tires will never chatter again.

Dave
Old 03-30-2005, 06:00 PM
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Coupe89
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St. Jude Donor '05-'06

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Just order one. You'll be happy!!!
Old 03-30-2005, 08:58 PM
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tempest
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you guys got me curious. i want to run some numbers. anyone got the wall thickness of the top frame member?
Old 03-30-2005, 09:07 PM
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MYCoupe
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Originally Posted by R-D Racing
... If you’ve ever gotten into a corner and felt your tires chattering, you will know what I’m talking about. The chattering is the result of frame flex and your camber going positive. With the Camber-brace, your tires will never chatter again.

Dave
I can attests to that. After I installed my Camber-Brace the car feels much more "planted" around turns, especially bumpy ones.
Old 03-31-2005, 12:36 AM
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CentralCoaster
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Yeah, i don't like these butt-dyno measurements either.

I think a good way to measure it, would be to install something like a camberbrace, but split into 2 pieces. Have the 2 pieces set up rub or etch eachother when the chassis bulges in or spreads out. Drive the stink out of it, bottom it out, hard cornering, etc.

The etch marks will tell you how much flex the camberbrace is eliminating. You can calculate the camber change with that to get some hard numbers.

Either that or ratchet the front end down and measure the camber difference with and without the brace.
Old 03-31-2005, 08:20 AM
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loiq
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Originally Posted by CentralCoaster
Yeah, i don't like these butt-dyno measurements either.

I think a good way to measure it, would be to install something like a camberbrace, but split into 2 pieces. Have the 2 pieces set up rub or etch eachother when the chassis bulges in or spreads out. Drive the stink out of it, bottom it out, hard cornering, etc.

The etch marks will tell you how much flex the camberbrace is eliminating. You can calculate the camber change with that to get some hard numbers.

Either that or ratchet the front end down and measure the camber difference with and without the brace.
In the snowmobile world the OEMs sometimes measure chassis stiffness by putting a bare chassis on a machine that tests for torsional stiffness. I wonder if someone could perform such a test on the front of a Corvette? Central Coaster this sounds like what you are proposing yet in a more basic form.

Or maybe a potentiometer such as those used to measure shock shaft speed/travel could be hooked between the upper a-arm mounts to measure the amount of deflection between them when under stress?
Old 03-31-2005, 05:53 PM
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tempest
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Originally Posted by loiq
In the snowmobile world the OEMs sometimes measure chassis stiffness by putting a bare chassis on a machine that tests for torsional stiffness. I wonder if someone could perform such a test on the front of a Corvette?....
sure. one primal way is to take three jackstands, a couple of hundred pounds in freeweights, and two thick plates drilled with a lug bolt pattern, with a bar rigidly attached to the plate perpendicular to it. the idea is to support the car on three corners near the suspension pickup points. on the end of the car with only one jackstand, bolt on the plate, bolt the other plate on the opposite diagonal corner, and hang some known weights equally on each corner. this will cause the chassis to flex in torsion.

by measuring the deflection of the free corner at the suspension pickup points on the frame, you can estimate the chassis stiffness since you know the torque applied to it (T=weight*G*moment arm length measured from center of vehicle). a little trigonometry will yield a close enough ft-lbs/degree number, but it will not be exact since the car is not twisting exactly on its roll axis.

doing this for chassis+suspension stiffness is a little trickier since you need to support the car on the uprights.

Originally Posted by loiq
Or maybe a potentiometer such as those used to measure shock shaft speed/travel could be hooked between the upper a-arm mounts to measure the amount of deflection between them when under stress?
interesting idea, but i think that might be a little difficult to execute, and i think the suspension compliance may overshadow the effects of the camber brace. i would try mounting strain gauges on the frame at certain places to get an idea of the amount of twisting going on.

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