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 Post subject: What causes this
 Post Posted: Sun Aug 19, 2007 11:02 pm 
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it would leave like this one pass butt the next one would be like this
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 Post Posted: Sun Aug 19, 2007 11:31 pm 
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here is some video

http://youtube.com/watch?v=F0WkrX2udSg

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 Post Posted: Sun Aug 19, 2007 11:49 pm 
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To my untrained eye it looks like something has to be moving under there.  Might post suspension details so Bubstr can take a whack at it.

George


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 Post Posted: Mon Aug 20, 2007 4:59 am 
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Could it be a bad shock or spring in the rear?

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 Post Posted: Mon Aug 20, 2007 2:50 pm 
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What I see is the same problem in both good and bad pictures. It's just a matter of degree. The only thing keeping it going straight is the big tires, if it does. Look in the picture how much you are compressing that right rear. That is the car telling you you didn't compensate for torque forces.

For every action, there is an opposite and equal reaction. This is a law of Physics, not a theory. Newtons first law of motion. This is how it works in a car. Engine supply's torque to the rear end by way of drive shaft threw pinion gear, as this torque is applied to the ring gear, it makes the rear assembly want to spin like a propeller, and it would if the ground wasn't in the way. So what it does is makes passenger side want to go up and drivers side go down. This is just the action side of the law. The reaction part is, with engine being mounted solid in chassis  it has to push off of chassis the same amount as the action. The reaction lifts drivers side front and pushes down on passengers side . This reaction with the help of gravity and some weight transfer is what keeps the right rear tire from just lifting that right rear tire off the ground.

Now think about what the springs and shocks are doing when this happens. The drivers side spring is getting extended, because rear going down chassis going up. The right side is compressed because of rear going up and chassis going down. Now think about what this does for pressure on the tire contact patches. When you launch, you have extra weight going to the rear. The drivers side, that is already getting more pressure from the tire being driven into the track from the initial torque action  has an extended spring. It will take a lot of the transfered weight and turn it into stored energy before it transfers any to the ground. At this point it don't need to because this is the side that has better traction at this time. The other side how ever is in trouble for traction, the spring is compressed, squeezed between the rear end and the chassis. It is transferring the weight that has been transfered to the rear, but not over coming the the torque force. (the first action) On top of this if you have too low an instant center, it hurts this side more than it helps the drivers side by making rear of car squat over all.

The cure is to keep both rear springs transferring the same amount of overall pressure from torque and transfer, to both contact patches. this is done with static weight, preload or anti roll bar or the combination of some or all. When you get it right neither rear spring will compress or separate much and launch very close to level.

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 Post Posted: Mon Aug 20, 2007 3:05 pm 
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Short wheelbased cars seem to be the worst about this problem. Never see it on a ladder bar car either.

Ladder bar cars don't have the problem because the bars are both solid to the rearend and makes the rear housing act like its own anti-roll bar. IMO ladder bars are under-rated. Most bracket cars would be better off with ladder bars.

Rick


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 Post Posted: Mon Aug 20, 2007 4:31 pm 
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How was your old Camaro Rick? Ladderbar or 4 link?


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 Post Posted: Mon Aug 20, 2007 5:11 pm 
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Rick360 wrote:
Short wheelbased cars seem to be the worst about this problem. Never see it on a ladder bar car either.

Ladder bar cars don't have the problem because the bars are both solid to the rearend and makes the rear housing act like its own anti-roll bar. IMO ladder bars are under-rated. Most bracket cars would be better off with ladder bars.

Rick


Yeah but they can be overpowered.  I think I was there with my old Camaro.

George


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 Post Posted: Mon Aug 20, 2007 7:05 pm 
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My Vega was the same way when I went with more power..Short time were inconstant if the track was not at it's best....Fix it with double adjustable shocks and a anti roll.........   =;

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 Post Posted: Tue Aug 21, 2007 7:21 pm 
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Thanks for all the info. Its not doing now but when I get the convertor back that was in it when the pics were taken I would like to have it fixed.

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