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Back End Is Jumping Off The Ground

r32matt
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r32matt Collaborator

r32matt

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Posted

Hey,

When im taking off quick and putting my foot down the back end starts jumping all over the place. its hard to get it on the ground and to make it stop bouncing. I have to keep taking my foot off the pedal and putting it down again. Does anyone know why the car isnt keeping on the ground. Could it be suspension or diff or something??

Thanks!

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kjb_r33 Experienced

kjb_r33

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Posted
If the cars "jumping" rather than simply breaking traction, id say its most likely your shocks/springs in the rear. Either the shocks are on their way out, or the spring rates are wrong. Perhaps a suspension shock could shed more light on it.

Shocks will do it, so will over inflated tyres

Sydneykid Grand Master

Sydneykid

Posted
Posted
Hey,

When im taking off quick and putting my foot down the back end starts jumping all over the place. its hard to get it on the ground and to make it stop bouncing. I have to keep taking my foot off the pedal and putting it down again. Does anyone know why the car isnt keeping on the ground. Could it be suspension or diff or something??

Thanks!

Sounds like axle tramp to me. Time for new shocks and check the subframe bushes.

:D cheers :rofl:

JCMarshall_Law Proficient

JCMarshall_Law

Posted
Posted (edited)

What your describing sounds like something more commonly known as axel tramp. It is pretty common in Skylines and probably many other models. A couple of ways to fix / improve the problem are:

1) subframe allignment bushes - these lock the rear subframe in position rather than having it able to move on its mounts.

2) good shocks / springs - another part of the problem is that the shocks / springs are not able to control the rapid oscillation of the rear end - a good combination of shocks ande springs will help.

3) As above make sure tyres are at correct pressure.

I've done all those three thinks and I don't have any problems at all lighting up the wheels withput them bouncing around.

Cheers.

Edited by JCMarshall_Law
Sydneykid Grand Master

Sydneykid

Posted
Posted
What about in the wet? I have new shocks and subfame bushes!

When you have semi wet road, dry patches, you can get tyre sidewall flex and release due to the changing traction. Raising the tyre pressures usually stops that.

:D cheers :rofl:

Gts-t Grand Master

Gts-t

Posted
Posted (edited)
When you have semi wet road, dry patches, you can get tyre sidewall flex and release due to the changing traction. Raising the tyre pressures usually stops that.

:laugh: cheers :laugh:

Hey gary,

i am running a 225/40/18, the road was not patchy at all as it was raining, and im running the 32psi you recommend for the street.

I must admit that half the time its ok, just some of the time it tramps a fair bit.

I was trying a few different things , ie slipping or dumping the clutch at different revs, changin to second at different revs and throttle % and i could sort or drive around it but i was a little suprised because it is so perfect in the dry :laugh:

Thanks SK

Edit: SK you were right, tyre pressures were at 26-27spi, Whoops :cool:

Edited by 26GTS

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