Originally Posted by
Barry_Hughes
I don't really understand the thinking of Xray on this, I can't really see why you would want to take toe out in the corner. More toe in yes, running stock you want to run less toe in on the straights and more in the corners, so I would have thought more adjustment to lower the ball stud would be ideal.
Other than than the ball stud for the shocks which is 5mm, does anyone know of a 4.9mm ball stud like the shock one, i.e. that you can screw into?
Xray used to do one part no 372651 but it is discontinued and no where seems to have any
I have used the ball of the outer front steering linkage #307455. Instead of the 9mm mounting post, I stuck a 16mm screw through the chassis, followed by a 3mm spacer, then I add the ball stud and fix it with an M3 nut.
With this setup, I can reach +2° gain of toe. Drawback is, you cannot add more shims, since the left ball joint will make contact with the belt.
I tested this a whole day on our very high grip, technical carpet track with 17.5 blinky and LRP CPX tires.
The track has only 1 long curve, directly into the main straight, the rest are tight s-curves and chicanes.
I started with 1° static toe in and +2° gain, but this was undrivable.
I then gave it 2° of static toe in, compressed I got ~3° toe in.
The massive toe in gain of the car gives plenty of steering into the corner and mid corner. As a drawback, on the outside bend of our sharp double s-curve combination my car had massive onpower understeer, which I couldn't get rid of the whole day.
My fast ARS laps were about as fast as the times without ARS, but these fast laps were very rare.
After that I switched back to the standard 9mm post, with no shims on the inside and 2mm on the outside. This gave no measurable toe gain.
Suddenly the onpower understeer after the double s-curve was gone, the car was easier to drive inside the s-curves, but was lacking a bit of corner entry steering.
From this testing session, I would conclude, the main ARS effect is the added rear steering, due to a toe in increase of the outside tire and a toe in decrease of the inside tire.
I think the idea that you can drive less static toe in because of the toe in gain under compression is wrong!
cheers
Ludger