Earlier this week we broke the news that the 2020 Dodge Challenger Drag Pak built by Mopar for NHRA and NMCA factory stock-based classes will be equipped with a new 3.0-liter Whipple supercharger. That information was discovered in the rules for the NMCA 2020 Factory Super Cars, but the information on that website wasn’t quite complete. They didn’t list the upper pulley size for the new Challenger Drag Pak Whipple supercharger, nor did they list the minimum required weight.


Those key bits of information still have not been updated on the NMCA website, but the NHRA has released the details for the SAMTech Factory Stock Showdown class, complete with the weight requirements and the upper pulley size for the 2020 Challenger Drag Pak.

2020 Challenger Drag Pak

As we revealed earlier this week, the 2020 Challenger Drag Pak in the NMCA Factory Super Cars and NHRA Factory Stock Showdown classes will be powered by a 354-cubic inch Hemi, topped with a new 3.0-liter Whipple supercharger. Our sources have told us that this supercharger was designed specifically for the Drag Pak program, so with the redesigned suspension setup, this Dodge drag car should be significantly quicker than the previous generation Challenger race car.

We also reported that the 2020 Challenger Drag Pak in the NMCA will run a 7.950-inch lower pulley, but the upper pulley size was unknown. Per the NHRA rules, Mopar teams will be running a 3.5-inch upper pulley. It should be noted that there are some differences in upper pulley sizes between the NMCA and NHRA, so the new Challenger Drag Pak could have a different upper pulley in the NMCA, but in the NHRA, the new Hemi racers will start with the 3.5-inch pulley up top.


Per the NHRA, the 3.0-liter Whipple with the 3.5-inch pulley on the 354-cubic inch Hemi is rated for 630 horsepower. The 2020 Camaro COPO is also rated at 630 horsepower while the Ford Mustang Cobra Jet is rated at 610 horsepower.

Finally, the 2020 Challenger Drag Pak will have a minimum weight of 3,575 pounds with a maximum weight of 3,600 pounds.

NHRA Factory Stock Showdown Competitors

While some of the numbers may vary for the NMCA, we have the key details for each of the top three competitors in the NHRA Factory Stock Showdown class. This is, of course, the 2020 Challenger Drag Pak, the 2020 Camaro COPO 350 and the Ford Mustang Cobra Jet 327.


All three cars have the same minimum and maximum weight numbers (3,575 to 3,600).

The Challenger Drag Pak comes with a 354-cubic inch Hemi with a 3.0-liter supercharger, sporting a 3.5-inch upper pulley and a 7.95-inch lower pulley. (Lower pulley numbers are from the NMCA – the NHRA doesn’t specify lower pulley size in their 2020 rule book.) This car is rated by the NHRA at 630 horsepower.

The new Camaro COPO has a 350-cubic inch V8 with a 2.65-liter Magnuson supercharger, fitted with a 3.58-inch upper pulley and an 8-inch lower pulley. This car is also rated at 630 horsepower.


The top of the line Mustang Cobra Jet for the 2020 NHRA season comes with a 327-cubic inch V8 topped by its own 3.0-liter Whipple supercharger, fitted with a 4-inch upper pulley and an 8-inch lower pulley. The Ford race car is rated at 610 horsepower.

These three race-ready muscle cars will meet for the first time at Amalie Motor Oil NHRA Gatornationals in Florida on March 12 through 15, with 7 more events completing the 2020 schedule. Of course, should one car prove to be particularly dominant, the NHRA can make adjustments to the pulley size or minimum weight to even-out the competition, but for now, the 2020 Challenger Drag Pak will take on the NHRA with a 3.0-liter Whipple, a 3.5-inch upper pulley and a 3,575-pound minimum weight requirement.