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12-19-2013, 02:16 PM | #1 |
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Wheel shimmy
1970 BBC Nova. Need to eliminate wheel shimmy when touching down after small wheel stand. Currently have stock front suspension with Calvert 90/10, Santhuff springs and loose bushing bolts. Looking at Global West upper control arms instead of tricking up the factory control arms. They look like they have bump stops but not long threaded suspension limiters. You thoughts please.
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12-19-2013, 02:25 PM | #2 |
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Re: Wheel shimmy
You didn't mention what class you run with your Nova or if it is a bracket car. Either way changing the upper A-arms won't fix the bump steer issue your having. Install a Bump Steer Kit and play with the adjustment until the lower A-arm and tie rod move in the same arch. I had the same problem on my Camaro and the kit solved the shimmy problem.
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12-19-2013, 02:41 PM | #3 |
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Re: Wheel shimmy
Toe out will cause wheel shimmy. My Camaro was doing the same thing. especially on the shut down if the brakes were applied to hard. I lowered my drag link to clear the pan which caused the bump steer issue and toe out condition. run your car up and down to see how much the toe changes. then make your adjustments.
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Mike Pearson 2485 SS |
12-19-2013, 04:32 PM | #4 |
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Re: Wheel shimmy
This is a bracket car. I was told that changing the uppers really helped bump steer. Is the Baer kit good enough? It looks like the only one that Summit sells for my car.
Last edited by Ron Gusack; 12-19-2013 at 05:59 PM. Reason: add |
12-20-2013, 08:14 PM | #5 |
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Re: Wheel shimmy
here is what I am thinking and have i experienced the same thing ,, your car is launching wheels up and its not coming down hitting the both the front tires at the same time (right front hitting first then then the left ) causing that shimmy ,, the tires are not turning or stop turning when in the air ,just like an air plane landing ,, that's your shimmy ,it steers to the right then to the left but stays straight for the most part ,send a video or picture gmonde
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12-20-2013, 09:00 PM | #6 |
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Re: Wheel shimmy
To correct this you need to figure how high the chassis rises at launch and set your caster and camber to zero so that when the chassis settles back down it does not go from a toe in toe out condition which is causing the wheels to flutter back and forth--- more positive camber can correct that. the car will be a little harder to steer because of the camber but it will want to run straight without shimmying/fluttering but who cares its going straight--- pay attention when you back up BACK UP SLOW it might not back up straight it will want to go either left or right but if you go slowly you'll be OK--- get video and watch just the front end/ wheels motion and watch for the fluttering when the wheels touch you'll see what I mean
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12-20-2013, 10:05 PM | #7 |
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Re: Wheel shimmy
The reason changing the upper ball joints to the longer type helps bump steer is because it reduces camber change. Combine that with a bump steer kit and you'll solve the problem as much as you can without major modifications. When we put longer ball joints on the orange car, then added the Santhuff shocks, it calmed things down a ton. There is a video from the coverage of the GatorNationals a few years ago that shows the car before we made the changes, in slow motion. The car looks nothing like that now, even coming down from a wheelie bar bending moon shot.
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Alan Roehrich 212A G/S |
12-21-2013, 10:16 AM | #8 | |
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Re: Wheel shimmy
Quote:
Thank You Kenney Kelley |
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12-21-2013, 10:51 AM | #9 |
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Re: Wheel shimmy
http://www.jegs.com/p/Specialty-Prod...33108/10002/-1
http://www.howeracing.com/c-560-howe...ll-joints.aspx http://www.qa1.net/qa1_motorsports/c...ll-joints.html
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Rich Taylor I/SA - 321 Last edited by HandOverFist; 12-21-2013 at 10:57 AM. |
12-21-2013, 12:12 PM | #10 |
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Re: Wheel shimmy
Kenney, you need Eddie Rezac's stuff for the Chevy II, if you don't have it already. Not sure if there are long upper ball joints for the Chevy II like there are for F and A body cars, the early Chevy II is vastly different from everything else.
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Alan Roehrich 212A G/S |
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