Understeer / adjustable shocks?

Understeer / adjustable shocks?

Author
Discussion

haynes

Original Poster:

370 posts

249 months

Tuesday 24th February 2004
quotequote all
Conventional wisdom is that adjustable shocks (spax) should be set to about 1/2 on the front and a 1/3 on the back. However i was suffering understeer particlulary on sharp cornering, ie roundabouts, the front wheels would just slide despite 1.5° negative camber(front) and 10x6 wheels. Having researched this a bit i read that softer suspension is required to increase grip, so i reset the front spax to 2 clicks and 4 on the back, body roll returned as did the grip on the front. I also had the back quite low, with only a cm or 2 of rake, but i wonder if this only increased grip at the back and hence understeer? Does anyone have a view on the above and comments on damper settings etc?

greenv8s

30,481 posts

291 months

Tuesday 24th February 2004
quotequote all
Damper settings do affect the amount of grip but this isn't the best way to set up the handling. Better to set the basic balance by controlling front/rear roll stiffness, and just use the damper settings to dial in transient behaviour on top of this.

Cooperman

4,428 posts

257 months

Tuesday 24th February 2004
quotequote all
Hi Haynes. I suggest that you check the track on the rear wheels. You must have 1/8" to 3/16" toe-in and zero to minus about 1 deg neg camber on a road car.
Always remember, if you stiffen up one end of a car you increase the road holding at the other end. Thus, increase roll stiffness at the back, reduce understeer at the front. Don't take this too far, however, or your power-off oversteer can become unmanageable, especially in the wet!
I usually set new Spax to 3 clicks on both ends to start with. To many people set them too hard which stops the suspension working properly on normal roads. Only go really hard for a track.

miniman

26,309 posts

269 months

Tuesday 24th February 2004
quotequote all
Question here about Spax settings. My Spax adjust from 0 to 24 clicks. When you refer to 3 clicks, is that 3 out of 24, or 3 out of another number from a different version of shocks?

How much stiffer is 3 out of 24 than a normal set of shocks? I'm running mine at about 20 out of 24 as the last time I used the car was on track (taken the engine out since then...)

Cooperman1

116 posts

250 months

Tuesday 24th February 2004
quotequote all
Hi James,
I have never counted the total number of clicks on a gas Spax, but from starting fully soft I normally go up 3 from there and try the car. I have fitted new ones all round last year and have done just one rally since. I now have 3 clicks on the front and two on the back.
Are you coming down to Welsh Wales this Saturday/Sun.
We're seeded at no. 8 out of 120 starters. I'm going to run my forest tyres as although there is less than 40 miles in the forests out of the total 180 miles, I reckon it will be slippy and muddy on a lot of the tarmac and we in the Historics are all mixed up with the moderns! I reckon we'll give them a run for their money, so long as the car holds together.

haynes

Original Poster:

370 posts

249 months

Wednesday 25th February 2004
quotequote all
greenv8s said:
Damper settings do affect the amount of grip but this isn't the best way to set up the handling. Better to set the basic balance by controlling front/rear roll stiffness, and just use the damper settings to dial in transient behaviour on top of this.
How do you alter the roll stiffness? The front rubber cones are quite old, and the rear ones are new, both are standard type. I have hi los all round.