Handling info

[45aken]

looking to make up a thread that contains info on what you can do to your car, and how it will effect the handling of it.

i'll start off with this simple table.
Component.......................Reduce Under-steer.....................Reduce Over-steer

Weight distribution...........centre of gravity towards rear........centre of gravity towards front
Front shock absorber.....................softer............... ................................stiffer
Rear shock absorber.....................stiffer.............. .................................softer
Front sway bar...............................softer.......... ....................................stiffer
Rear sway bar...............................stiffer......... ......................................softer
Front tyre selection1.............larger contact area.........................smaller contact area
Rear tyre selection...............smaller contact area........................larger contact area
Front wheel rim width/diameter........larger............................ ..................smaller
Rear wheel rim width/diameter........smaller........................... ...................larger
Front tyre pressure..................higher pressure.................................lower pressure
Rear tyre pressure..................lower pressure................................. higher pressure
Front wheel camber.............increase negative camber................reduce negative camber
Rear wheel camber.............reduce negative camber..................increase negative camber
Front height*............................lower front end.................................raise front end
Rear height*.............................raise rear end.................................lower rear end
Front toe in.................................increase....... ....................................decrease
Rear toe in..................................decrease...... ....................................increase

height*- normally effects affect camber and roll resistance
PS this is a very simple mock up table for a general idea about how things effect your handling.

[Hydra]

Suspension travel can have a big effect too, especially if you start hitting the bump stops. Speaking of which, what is the best way to figure out how much can be chopped off a bump stop?

[RobertoX]

You could figure it out but most books I have seen just recomend to chop off a maximum of 1 'section' of the bump stop. If you do this and it solves your problem good (check that if you hit it you wont be scraping anything), if you do this and it doesnt solve your problem then you need to buy some smaller bump stops and adapt them (and do some summs to figure out what height & size).

[EldarO]

Id be interested in the effects that changing castor has too

Eldar.O.

[RobertoX]

More castor = more self straightening effect on wheel

also = more camber change on turning steering wheel (insidel wheel goes +ve outside wheel goes -ve)