Originally Posted by
Slapjack
I have a question regarding roll center adjustment. How do I lower the roll center on the d413 to get more traction? Wouldn't you normally add spacers under the ball stud (raise the ball stud). But the rear ball stud is mounted underneath the camber plate. So what do I do? Anyone mount it on top of the plate? I have the carbon fiber camber plate which has one extra hole but I'm not even sure what moving to the other holes does. I was going by one of tessmanns setup sheets which says to use 1mm spacer between stud and camber plate but that is raising the roll center since is mounted on the bottom of the camber plate and I want to lower it. I think. Lol
Originally Posted by
Slapjack
Thanks guys... If I adjust the rear end do I also make a change to the front end roll center? Or should that remain constant? And the outer hub hole you are referring to is the hole where the hinge pin goes thru right? So I either want to make the inner stud higher or make it lower at the outer hub area correct?
If you want to raise the inner ball studs, put the shims of the desired thickness under the plate where it mounts to the diff housing. I know I'm a genius right? If you go with a shim that is more than 1mm, make sure to use screws that are longer by the same amount as the thickness of the shims (the stock screws are 10mm so if you go to a 2mm shim use 12mm screws). I didn't like how the inner ball cups interfered with the plate at full suspension compression if you run the inner hole on the plate so I raised my plate up by 2mm, and added a 2mm shim under the inner ball stud. This gives the ball cup clearance without having to grind away material from the plate or cup.
Also as Gertsch posted you can make roll center adjustments with the hinge pin mounts too.
As for making an adjustment to both the front and the rear of the car. It depends. All adjustments are to change the balance of the car. Sometimes an adjustment may fix one thing, but create another issue. If you have little idea what adjustments do, run the car, make A SINGLE change, then run it immediately again to feel the difference that one change made. I've been in the hobby for 25+ years, I know what changes do what. If my car is that far off, I can usually change several things at once, and get the car to be much better.
Originally Posted by
wittyname
The rear hub has 2 holes for the pin to go through . These adjust roll center also. The upper hole makes for a lower roll center I believe.
While changing which hole the hinge pin goes through on the hub will change roll center, it will also change the ride height, which if he resets (you should always check ride height and camber after any change) will change how much droop his car has, which will effect weight transfer. Also, what if his hinge pin is already in the upper hole?