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Axel Hop - Information And Questions

Taso84
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Taso84 Mentor

Taso84

Posted
Posted

Ok.... after having major axel tramp issues and installing pineapples, (which reduced it a little) i have done some extensive research on this "axel tramp" phenomenon.

Basically as well as all the other causes of tramp there is one more to ass:

Tramp can be caused by having a larger unsprung weight on ur car - that means the weight of everything that is not on the springs, ie the wheels.

So far the suggested solutions to axel tramp are

1) pineapples

2) increasing damper (ie harder suspension) or installing coilovers. Bit confused on this, some pple say u need harder suspension some pple say u need it to be softer

3) Better/softer rubber.

I have also found the following solutions from my research:

1) Installing traction bars (slapper bars) that basically hits the springs with a rubber bumper when too much torque is applied.

2) lowering the front upper control arm mounting points. I have no idea how/why this would help but apparently it does. Prob a simialr mod to an aftermarket control arm (not sure tho)

3) Lightweight rims: Related to suspension/damper reason, since usually its that the shocks are not good enough to cope, especially after hp gains.

My car is this:

r33 GTS-t 190rwkW

Stock rims with hard compound tyres (set to 25psi otherwise car is undriveable)

Tein HA coilovers (adjustable damper)

whiteline pineapples

adjastable castor rods (i didnt know this till a week ago)

Basiacally ive been doing a bit of experimenting and i still cant seem to fix the axel hop, i think i might take the plunge and change the tyres. On normal pressure the car bounces around so much u cant keep the accelerator on constant throttle - no joke.

My question to sydney kid is this: Do u think traction bars will fix the axel tramp? If not, what should be my next move other than getting new rims/tyres.

Also can anybody answer once and for all is it better to have the damper on hard or soft to combat axel tramp.

What are ur thought ppl...?

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kjb_r33 Experienced

kjb_r33

Posted
Posted
Ok.... after having major axel tramp issues and installing pineapples, (which reduced it a little) i have done some extensive research on this "axel tramp" phenomenon.

Basically as well as all the other causes of tramp there is one more to ass:

Tramp can be caused by having a larger unsprung weight on ur car - that means the weight of everything that is not on the springs, ie the wheels.

So far the suggested solutions to axel tramp are

1) pineapples

2) increasing damper (ie harder suspension) or installing coilovers. Bit confused on this, some pple say u need harder suspension some pple say u need it to be softer

3) Better/softer rubber.

I have also found the following solutions from my research:

1) Installing traction bars (slapper bars) that basically hits the springs with a rubber bumper when too much torque is applied.

2) lowering the front upper control arm mounting points. I have no idea how/why this would help but apparently it does. Prob a simialr mod to an aftermarket control arm (not sure tho)

3) Lightweight rims: Related to suspension/damper reason, since usually its that the shocks are not good enough to cope, especially after hp gains.

My car is this:

r33 GTS-t 190rwkW

Stock rims with hard compound tyres (set to 25psi otherwise car is undriveable)

Tein HA coilovers (adjustable damper)

whiteline pineapples

adjastable castor rods (i didnt know this till a week ago)

Basiacally ive been doing a bit of experimenting and i still cant seem to fix the axel hop, i think i might take the plunge and change the tyres. On normal pressure the car bounces around so much u cant keep the accelerator on constant throttle - no joke.

My question to sydney kid is this: Do u think traction bars will fix the axel tramp? If not, what should be my next move other than getting new rims/tyres.

Also can anybody answer once and for all is it better to have the damper on hard or soft to combat axel tramp.

What are ur thought ppl...?

Was always my belief that traction bars were fitted on LEAF springs only, meant to stop the leaf spring twisting and then releasing (causing the axle tramp).

salad Veteran

salad

Posted
Posted (edited)

here

10% of the time it's tyre pressures, the sidewall flexes and releases. Try pumping the tyres up and see if the axle tramp stops and/or gets less.

5% of the time it's worn subframe bushes, since you have fitted a rear subframe alignment kit (pineapples) I suspect that isn't the problem in your case.

25% of the time its drive shaft angle, the car is TOO LOW and the angle of the universal joints are winding up the drive shafts. If your car is lower than 345 mm centre of wheel to guard on the rear, then try raising it up.

60% of the time it's incorrectly matched spring and shock damper rates. The rebound (extension) damping is not sufficient to control the oscillations of the springs. Standard springs with worn shocks get this problem. BRAND NEW aftermarket coil overs get this problem where the spring rate is too high for the shocks to control.

Once you have eliminated 1, 2 and 3, then your problem is #4

cheers

Edited by salad

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