Originally Posted by
narcotiks
im a little confused about the whole ackerman setting changes. I know that the ackerman is the angle of the inside and outside wheels and that changes slip angle and all that. What does adding ackerman shims or using longer steering links or having more shims on the steering knuckle putting the steering link closer to the ground actually do?
what would you be seeking when making a change to the ackerman, and what scenario would you be changing ackerman or shimming things in?
i realise that it changes the angles of the wheels and i have researched it but I'm still struggling to understand so i thought i would ask here for a more practical explanation.
Thanks
There are 2 variables here, ackerman and bumpsteer. Adding shims at the knuckle to change the link angle only changes bumpsteer, a 1mm change here can provide a decent change in steering, so you should try it. It feels to me that adding more shims makes the car more aggressive on turn in.
With the '12 rack there is no length change available, you can use the forward holes in the steering knuckles, but I don't know anyone using that setting. You are left with the shims on the rack pushing the links forward or back (always remember to change this in line with your wheelbase shims). Changing the ackerman this way has varied effects on different parts of the corner depending on grip available, usually people run 1 or 2mm shims.