VW and Porsche Torsion Bar Rates
Sway-A-Way VW and Porsche Torsion bar rate tables are used to compare spring rates when changing length, diameter or both. The numbers in the table are in in-lbs per degree of twist. The numbers show the relative stiffness in relation to diameter and length.When used with specific suspension geometery, wheel rates can be calculated from these numbers. The formula for that is F=57.3 x T/L^2 where T is the number from the table and L is the arm length squared.
F is the wheel rate in lbs per inch.
T is the number from the table.
L is the arm lenght in inches from the inner pivot straight back to the stub axle center line.
In general, when wheel travel increases, spring rates can decrease. Track cars that run on asphault will generally use higher spring rates than Auto Crossing and street performance cars. For track performance, high spring rates front and rear will perform better. Changing preload on torsion bars changes the ride height, but does not change the spring rate. Sway-A-Way manufacturers adjusters that are used to make it easier to change ride height. Please see adjustable spring plates and center quick adjusters for the rear suspensions. They can be used to easily change ride height and balance corner weights with out having to disassemble the suspension.
|VW AND PORSCHE TORSION BAR RATES|
|24 1/16″ (611 MM)||21 3/4″ (552 MM)||24 11/16″ (627 MM)||26 9/16″ (675MM)|
|APPLICATION||911/914 FRONT||VW REAR||911/VW REAR||924/944/VW REAR|