Momentum drift

[totta Crolla]

I am in the process of having some custom rear springs made and am now looking at spring rates. The car is used for tarmac rally and does not have a lot of power. Ideally then it would need to drift the back end slightly at high speed but this should not be with wheelspin. What I'm looking for is a setup where I could enter a long corner at high speed and the car would naturally turn in without understeer and be more biased toward oversteer.
I have looked at the drift spring rates but are these high rates used more with wheelspin than momentum to create the slide ?
thanks for any input.

[Apolan]

i think you'll be looking more at shocks balance setup than springs. I guess what you want is a slower rebound rear / faster bound front, so rear tyres would loose traction on lift-off and braking. You can also set the brake bias more towards the rear. But this is much more complicated than this. A good article on this subject can be found here:

Neil Roberts Article on Shock Tuning
http://www.smithees-racetech.com.au/theo...tune1.html

Oversteer / Understeer Corrections
http://rogerkrausracing.com/TechSheets/overunder.shtml

[SutteR]

Not being a smart-ass but this understeer-oversteer write up is faulty in more lines.

A usual drift setup for drift is 8kg front spring and 6kg rear spring. A bit stiffer front and a bit more stiffer rear swaybar is commonly used. Wider front track and not that much wider rear track is also common.

If you need more neutral setup you should soften the rear with stock or only a bit stiffer than stock rear sway bar. The F/R spring ratio for drift is the above mentioned ~1.33:1, but for neutral it's more like 1:1. Also, better to use softer front than harder rear which you could control only on very smooth tarmac.

[Jan Pedersen]

Just about all rally cars here in DK uses 6 kg/mm front and 5.1 kg/mm rear springs. About 90-95 % is tarmac... I have this setup on my car and I like it very much. For road I set it up for just a little understeer, neutral for trackdays and oversteer when I want to play

[totta Crolla]

Jan Pedersen Wrote:Just about all rally cars here in DK uses 6 kg/mm front and 5.1 kg/mm rear springs. About 90-95 % is tarmac... I have this setup on my car and I like it very much. For road I set it up for just a little understeer, neutral for trackdays and oversteer when I want to play

Currently my car has 5.3 front and 3.5 rear with Bilstein dampers. Stock anti roll bars front and rear. What would you think about 5.3 front and 5.1rear ?

[Jan Pedersen]

I think they are a bit too close 4.8 maybe better. But you could try it out

[totta Crolla]

Ordered 5.1kg springs, I'll give 'em a try and see
I can change the fronts easily as they are 2.25" coilovers

[Jan Pedersen]

This will be interesting I think... I always wondered about front to rear ratio 5.3 kg/mm front isn't too hard but it depends on road condition.

A trackdays I wouldn't mind 8 / 7 kg/mm but my car isn't a racecar