Image courtesy NHRA/National Dragster

The NHRA revealed last week the rule amendments for the 2013 Pro Mod Drag Racing Series, containing some changes in regards to the turbocharged and nitrous oxide-assisted  combinations in a continued effort to maintain performance parity between the three engine/power adder combinations allowed in the category.

The turbocharged racers, who were required to run a spec turbocharger unit last season but largely dominated the performance charts, will have a reduction in their minimum weight from 2,700 to 2,650 pounds and will also be allowed to run turbos from any manufacturer, as long as they aren’t any larger than 88mm and meet SFI 61.1 specification. Intercoolers will also now be prohibited. To control the boost — and in effect, the performance — of the turbo cars, racer will be required to utilize an NHRA-specified boost controller, with which the maximum boost level settings will be controlled by NHRA officials.

The nitrous combination will now be allowed to use water injection, a form of technology that involves the spray of water into the cylinder or the incoming air-fuel mixture to cool the combustion chambers, creating higher compression ratios and therefore more horsepower.

The supercharged racers will see no adjustment in their regulations for 2013. The supercharged combination was the benefactor of a late summer rules adjustment to bring parity to the class, as their minimum weight was adjusted by 50 pounds, down to 2,600.

The turbocharged won half of the 10 events contested this season, with the nitrous contingent scoring three and the supercharged racers two. Which combo will rule in 2013? We’ll have to wait and see.