National Guard ADRL Updates Supercharger Rules

O’FALLON, MO (June 30, 2009) –The National Guard American Drag Racing League (ADRL) announced today several rule clarifications related to the use of superchargers in its Pro Extreme and Extreme 10.5 classes.

• Use of any size centrifugal, roots-type or screw-type supercharger allowed.
• Maximum overdrive for a roots-type supercharger is 1.70 (70 percent over). 
•  Maximum overdrive for a PSI screw-type supercharger is 2.28 (128 percent over). 
•  Maximum overdrive for a Whipple screw-type supercharger is 1.60 (60 percent over). 
•  All screw-type superchargers must be certified to SFI Spec 34.1 and overdrive limit established to be eligible for ADRL competition. 
•  Any new screw-type supercharger must be approved for competition prior to competing at an ADRL event. 
•  All screw-type superchargers must display a current SFI Recertification tag. 

“We haven’t had a problem in this area, but these rules are intended to stave off any issues before they arise,” National Guard ADRL Executive Vice President of Competition Bubba Corzine explained. “We just want to put it in writing and make sure that all of our race teams know where we stand in regard to these power enhancers.”