Roll center Movement/Camber gain

[chevy34]

Can any one help me with some geometry ideas.

I am Looking at building a new Body shell for our current car and probably redesign the front and rear suspension.

It is a large sedan front engine V8 rear drive. Tyres width around 285 front 305 rear.

I have been playing with my suspension programme and come up with some Questions

1. How high should I have the front and rear roll centers down round 2" above Ground or up closer to 4" and how much higher should I have the rear than the front.

2. When the car rolls how far is exceptable for the roll center to move left or right.

3. If going to an IRS how much camber gain is enough and should the rear roll center movement be the same as the front.

4. What percentage of Anti dive and Anti squat should I be looking for.

5. With an IRS do you look for a (Scrub Radius?) and a (KPI?) I guess this is what it would be called on the rear as well. (If its not what should I aim for in these areas)

[tristancliffe]

1. Don't know. Rear is generally 'a bit' higher.
2. Inches or Yards, depending on what other things you give more importance.
3. Enough to keep your outside tyres within their working range, but possibly without torturing any of them under braking or acceleration...
4. As little as you can get away with. 0% is preferable in my opinion - cars just 'feel' nicer without it.
5. Yes, you need to worry about scrub radius and SAI (Steering Angle Inclination, which is the same thing as KPI, but for cars that don't have kingpins).

Ultimately you can have whatever you like, but YOU have to come up with answers and compromises to suit the weight, the speed range, CoG heights, types of tyre, types of circuit etc...

[chevy34]

I have made a mistake with question 5
I was meaning with the rear suspension does it mater where the intersection line of the rear top and bottom ball joint meet the road in relation to the center of the rear tyre.( I was taking a stab that this also would be called scrub radius)