Hey guys,
Recently i made the change to a lsd rear end and whilst i was at it i changed to a harder rear spring rate (700lb up to 900lb) to try and eliminate some of the squat that SR 16s are prone to on take off and gear change. But ever since, I have been experiencing what i can only describe as axle tramp. Whenever the tyres start to spin up from take off or low speeds, i start to get bounce from rear end.

Im using the kyb true monogas hd rear shocks which were fine with 700lb springs, but since the change to 900lbs and the extra traction of the lsd, the problem has reared its ugly head.

I know this is a more common problem with live axled rear ends, but has anyone experienced this with their irs 1600s?? Anyone suggest a proven solution? Baz, any advice on a shock to match a 900lb spring?

Cheers Tony

I used to have the same problem with earlier 1600's. They ran heavy springs 900lb and up. The problem was not as bad with shocks valved to suit, but still there. Moved the spring rate back down with valved shocks and presto burn outs became heaps of fun. With suspension there is always a compromise. The compromise that suits you, rather the that pisses you off the least is the way to go. I never tried a rear sway bar to rid the issue. If it would help or heed I'm sure Baz can add much more than me. We need to remember we are driving cars which are 40 years old, while the design of the rear end is okay it's far from perfect and we have to tweak it and live with compromises .

Another otion is to also use a boost controler that is gear selective. ie 1st 10psi 2nd 12-14psi 3rd 20psi 4h

Tame the beast

_________________
1928 Model A CC Pickup

Thanks mydato, good to know someone has had a similar experience. I might have to change back to 700s for a while and weigh up the pros/cons.
I am able to gear select boost with the AVCR, but i dont think im prepared to lower the boost and potentially lose the smile from my face hahahahaha.

I got the same issue.
1000lb rear springs/ konis.
i found rear grip is way better with the heavy rear springs, but the tramping is annoying, and cant be good from the driveline.

First of all, ARB's, anti roll bars, do nothing for axle tramp.Secondly, shocks have to be valved to suit spring rates. If you want to get serious go to my topic a couple down, there is a lot involved.

_________________
Richard..........http://www.youtube.com/watch?v=rqM9_Wq-TKc

As mentioned even valving shock to springs will not fix the problem when running high pound springs.

_________________
1928 Model A CC Pickup

i can back up mydato's advice and say that after changing back to 700lb springs, the problem doesnt seem to be as severe

1100LB springs + Commodore Bilsteins = no tramp

_________________
1971 Datsun P510 SR20DET 276 rwkW
2005 Mercedes AMG E55 350 kW
1969 Datsun P510 L20B EFI 95 rwkW
1975 Ford XB Fairmont GS Wagon 179rwhp
1980 Escort Van SR20DET unfinished
2002 Suzuki GSX1300R Hayabusa 185hp

I used to run the same setup as turbovan, no issues either

_________________
Dan.
Official organisor of Thursday nite pizza.

Hey turbovan/green510,
what series commodore? i would like to keep a stiffer spring in the rear if i could, so that might be the answer.

Can't remember off hand... I think it was VK or something. You need to change the bottom bush because the commodore has a smaller pin, but that's easy.

Give SWR a call Stewart will probably be able to help.

_________________
1971 Datsun P510 SR20DET 276 rwkW
2005 Mercedes AMG E55 350 kW
1969 Datsun P510 L20B EFI 95 rwkW
1975 Ford XB Fairmont GS Wagon 179rwhp
1980 Escort Van SR20DET unfinished
2002 Suzuki GSX1300R Hayabusa 185hp

Confirmed VK SS

_________________
Dan.
Official organisor of Thursday nite pizza.

Any issues with the VK SS shocks in the rear such as springs not been captive?

I'm running lowered king springs and need new shocks.

Any info on which bush to suit the bottom of the shock?

swanny

Good stuff to know I'll be looking at getting datsport 1100lb rear springs and was wondering about shocks. I currently have spax adjustables with unknown rate cut king springs. Are the VK Bilsteins just standard replacement parts or do you have to order them specially? Also what bushes do you use to get around the different sized bits? 1600 ones?

Pretty sure I just used 1600 rubbers in the commodore shock lower eye. Was a long time ago though - back when VK's were the current model (and I worked in a GMH spare parts place )

I ran Selby's lowered springs which were captive.

_________________
1970 ex Group A Rally P510
1971 P510
1972 180B SSS
1965 SP310 Fairlady
1966 SP311 Fairlady