Suspension TECH Including Brakes, Wheels and tires

          
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  #61  
Old 10-02-2007, 11:00 PM
78 GHOST 78 GHOST is offline
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Here are two more points:

1. It might be worth installing 200# of ballast on the RH side for a period of time. I'm wondering if riding alone all the time leaves a "set" to the suspension. Even if everything is new and in good shape, perhaps it tends to come to rest with the LH side down. I'd be particularly interested in the stance of cars which have had the low friction ball joints installed. It might be that the friction of the ball joints keep the suspension from freely articulating and achieving a level stance after the driver exits the vehicle.

The 200# of ballast would permit the vehicle to come to rest at as even a stance as possible. If this is the case, I might be inclined to install low friction ball joints.

2. I have a Camber Correction Kit installed on my GTO. This kit essentially adds 2" to the length of the spindle. I suspect that in addition to correcting the camber, it also tends to provide a better geometric arrangement of the control arms.

The stock suspension has the upper control arm angled downward at a pretty steep angle. The lower control arm is much closer to level.

As we all know, these cars were engineered for the masses. The average driver needs a car which will provide stable and forgiving handling. Of the choices available (oversteer, neutral, understeer) the engineers chose the safe option, understeer. It's this combination of poorly matched angles which provides the understeer desired by the engineers. Upon compression of the suspension, the tire on the outside of the turn tips outward at the top, this is termed positive camber. The concept provided for reliable and safe vehicles which tended to plow straight ahead instead of snapping in response to a sloppily executed steering input.

OK, now that we have examined the preliminaries the time is right for concept #2. I think the possibility exists that because of these unequal angles and poor suspension layout, the suspension will resist moving freely. This is amplified by the great amount of friction of the ball joints.

To summarize, I suspect that the only way to totally eliminate the dreaded A-Body leans is to utilize the Global West Del-A-Lum free moving bushings, AFCO low friction ball joints, a tall spindle conversion, and a good alignment.

The other option is to load 200# of ballast.. not nice.

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  #62  
Old 10-17-2007, 07:37 PM
gtopont gtopont is offline
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Join Date: Mar 2005
Location: RINGWOOD NJ
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Thumbs up lower on one side ? try this !!!!

the end of your rear coil springs ends/tails SHOULD be para/with your rear....thats called indexing !!!! that is ,the end runs the same direction as your axles/rear...get it ....

  #63  
Old 12-03-2007, 07:36 PM
RANDY P RANDY P is offline
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Update -

Finally said to hell with it and had it checked at the body shop today when I took it in to get some damage to the nose fixed.

Sure enough, it's the indexing of the springs up front that is the issue. Body shop did some pretty simple diagnosis to figure out what was bent on the car. So stinkin' easy I'm kind of ashamed I didn't do this myself..

Close inspection of the frame checked out OK- no crunches or anything weird.. Lifted back end of car then hung it on jackstands on the frame on a level surface while front was on the ground. 1" difference and drivers side low.

We then dropped it back down and lifted front end then hung car by frame rails from the front, re-measured the back going through the center of the wheel and fenderwell - dead even- literally dead even. Lifting the nose and hanging it by the frame shows the frame is OK and rear suspension is in fact even.

Body guy then noted the springs were 1/2" turn on LH side off and 1/4 turn off on RH side.

Sure enough,it's good now

rjp

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Last edited by RANDY P; 12-03-2007 at 07:47 PM.
  #64  
Old 12-06-2009, 04:36 PM
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mrgto mrgto is offline
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Great information guys!

  #65  
Old 05-26-2011, 11:00 PM
Stinkyee Stinkyee is offline
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Default My Turn

69 GTO low on drivers side rear. After reading all posts I replaced rear springs with new MOOG ones. Did not Fix it. Purchased the 1" aluminum spacer and put it under left rear coil. Did not change. I have ordered 2" drop spindles for the front and when I install them I will index and measure the coils. I hope this helps

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