Torsion Bars... Best Diameter for a Lowered Street / Autocross car?
You'll just have to take a stab at it and then work from there. There is no perfect torsion bar rate, it all depends on what you are trying to do as well as the rest of the combination. Once you have the car running and driving you can start to work on tuning the combination. At that point you might decide to add more rate up front or add rate to the rear or add more bar or reduce the bar or revalve the shocks or change air pressure in the tires or add tire or whatever.
You'll just have to take a stab at it and then work from there. There is no perfect torsion bar rate, it all depends on what you are trying to do as well as the rest of the combination. Once you have the car running and driving you can start to work on tuning the combination. At that point you might decide to add more rate up front or add rate to the rear or add more bar or reduce the bar or revalve the shocks or change air pressure in the tires or add tire or whatever.