TEST THREE Weight on center Weight in Left Rear Weight in Right Rear LF RF LF RF LF RF 990 866 988 851 971 870 (28.2%) (24.6%) (28.1%) (24.2%) (27.6%) (24.7%) LR RR LR RR LR RR 823 837 846 831 818 857 (23.4%) (23.8%) (24.1%) (23.6%) (23.3%) (24.4%) Total: 3,516 Front/Rear: 52.8%/47.2% Front/Rear: 52.3%/47.7% Front/Rear: 52.3%/47.7% Left side: 51.6% Left side: 52.2% Left side: 50.9% Right side: 48.4% Right side: 47.8% Right side: 49.1% Moving weight behind the rear axle multiplies the effect. We spoke to an NMCA racer who mentioned that just moving ballast several inches behind the rear axle was sufficient to radically increase the car's tendency to wheelstand. He was able to tune the launch with minor weight repositioning. Moving weight behind the rear axle multiplies the effect. We spoke to an NMCA racer who me This was an interesting test because 45 pounds increased the total rear weight distribution percentage from 46.5 percent with the battery in the rear to just over 47 percent. And when the weight was moved to the right side alongside the battery, the right-rear weight jumped to 24.4 percent, which is 44 pounds of additional downforce over the right-rear tire. If we calculate cross weight in this final configuration, the LF/RR comes in at 52 percent, while the RF/LR direction is 48 percent. Increasing the load on the right rear may not be worth carrying the extra weight unless the car has traction problems. Remember that under acceleration, the rear axle attempts to lift the right-rear tire off the pavement. Additional weight on this corner (in addition to the battery) may improve acceleration despite the weight penalty. In addition, there may be handling issues here because the cross weight difference is 140 pounds, which is significant. PARTS LIST DESCRIPTION PN SOURCE PRICE Craftsman Laser Trac LM013N Sears $34.99 Speedway scale levelers 91082650 Speedway Motors 24.99 Proform digital scales 67650 Summit Racing 729.95 Proform wireless scales 67651 Summit Racing 1,097.99 SOURCES Sears Craftsman Hoffman Estates IL 800-377-7414 www.sears.com/craftsman Proform Parts Roseville MI 800-521-1005 www.proformparts.com Speedway Motors 340 Victory Lane Lincoln ME 68528 800-979-0122 http://www.speedwaymotors.com « | 1 | 2 | 3 | 4 | 5 | View Full Article By Jeff Smith Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!