Allen Racing Tech

12/04/2021

06/13/2021

Price: $12 per bar

Sprint Car Torsion Bar Rates (12” Steel Arm)

Bar Master Range Avg

925 200
950 (215-225) 220
975 (240-245) 243
1000 (255-270) 263
1012/1015 273
1025 (275-290) 283
1035/1037 293
1050 (295-315) 305

Bars are dynoed using a 12” solid steel arm for the sake of comparison. Bump and rebound differences are more noticeable because of the stiffness and higher speed of the shorter steel arm. Bars can also be dynoed with aluminum arms instead to analyze manufacturer & stiffness. Below is actual dyno data.

LF 1000 12” SOLID STEEL ARM 261.0
SAME BAR 15 1/4" SOLID STEEL ARM 163.1
SAME BAR 15 1/4” ALUMINUM LF ARM 153.5
SAME BAR 14 11/16” ALUM RR ARM 163.0

Good vs Bad Bar:

Difference between bump and rebound dictates how lazy a torsion bar is. The greater the difference, the worse memory a bar has. Good bars come to a sharp point on the graph between bump and rebound. Bad bars have a rounded or squared off nose that “yields” lower rebound forces during the return stroke.