Faced with the prospect their Pro Stock cars could be on the verge of out of control, the NHRA has implemented three rule changes aimed at increasing down force on the 200 mile per hour coupes during the final 320 feet of the quarter mile drag strip.

Beginning next weekend at the NHRA Gatornationals, Pro Stock teams will sport a larger wicker bill on the wing, increased by an 1/8 inch to 3/4 inch. The teams will have to install a splitter on the front end similar to those used in NASCAR but not as visible.

On a NASCAR Car of Tomorrow, the splitter is a large carbon fiber piece attached to the bottom of the front bumper. Unlike their splitters, which use strut rods, the Pro Stock version will be 44 inches wide and stick out 3/8 inch from the nose and extend two inches  behind the front bumper.

Faced with the prospect their Pro Stock cars could be on the verge of out of control, the NHRA has implemented three rule changes aimed at increasing down force on the 200 mile per hour coupes during the final 320 feet of the quarter mile drag strip.

Beginning next weekend at the NHRA Gatornationals, Pro Stock teams will sport a larger wicker bill on the wing, increased by an 1/8 inch to 3/4 inch. The teams will have to install a splitter on the front end similar to those used in NASCAR but not as visible.

On a NASCAR Car of Tomorrow, the splitter is a large carbon fiber piece attached to the bottom of the front bumper. Unlike their splitters, which use strut rods, the Pro Stock version will be 44 inches wide and stick out 3/8 inch from the nose and extend two inches  behind the front bumper.

Both the splitter and wicker additions are expected to create more downforce on both ends of the car.

Will these adjustments slow down the cars?

“I honestly don’t know,” said Rick Jones, major Pro Stock chassis builder and crew chief for his son Rickie Jones. “No one really knows now until we test next week what affects the changes will have.”

When more downforce is added to the Pro Stock cars, it actually compresses the shocks and without testing, the level of compression remains unknown.

“We might have to make some spring changes to get the car back to what we were used to working with,” Jones explained. “We just want to make sure the car is right. This will affect the overall set-up of the car.”

Increased downforce will be the main objective for the rule makers next weekend.

“It can add 30 pounds of downforce depending on what kind of car you’re running,” estimated Jones. “Adding that to the car can affect each body style differently so it is really a guess at this point until we run the car down the track and see what it does.”

The NHRA has also required the Pro Stock teams maintain a minimum rear weight on the car. This regulation does not affect the traditional 2,350 pound minimum weight for Pro Stock. However, next weekend, all Pro Stockers will be required weigh a minimum 1,090 pounds on the rear, a first for the class.

The changes to accommodate the increased downforce will likely include four-link and suspension changes need to establish a new combination to ensure the chassis works correctly. What remains to be seen is whether the added rear weight will cause the cars to wheelstand more than usual. Too high of a wheelstand for Pro Stockers, can adversely affect their performance and consistency.

Jones estimates most cars have run typically 1,070 to 1,100 pounds on the rear of the car.

In the past, many of the teams have freely moved weight around the car to better navigate a race track and adhere to better air conditions. Moving weight has proven to be a valuable tuning tool for some teams. Weighing the rear of the car in the past is something a majority of the teams are practiced in.

So how does the NHRA accurately measure the rear of Pro Stockers, with three different manufacturers, and maintain an accurate process?

“Now you’ll have to weigh the car using the standard procedure,” Jones explained. “Then you will have to roll the front tires off the scale and weigh the rear half.

“Since all of the cars have the same wheelbase and pretty much the same driver placement, the only issue you might face is from racetrack to racetrack the scales may differ on how you weigh the back.”

Pro Stock driver Allen Johnson is one of the dozens of drivers expected to test this weekend in either Bradenton, Fla., or Valdosta, Ga.

Johnson’s teammate Vinny Deceglie was one of two Pro Stock drivers who crashed in Phoenix two weeks ago, prompting the NHRA to seek support of the eight remaining drivers to finish the event in Gainesville, Fla. Those crashes and the treacherous conditions at the NHRA Arizona Nationals also served as the impetus for the three new changes.

“I think the NHRA jumped the gun before they knew what was wrong,” Johnson said. “Once the NHRA found out the reason for the problem, traction compound, they should have rescinded the rules. We don’t need them.

“The wickerbill is the only rule change that is going to work like they want it to work. The other two won’t affect the car down track at all. To be honest, the front thing [splitter] is probably going to unload the cars and make them worse. Rear weight won’t do anything to change these cars at speed. It will only affect them on the starting line. We’ve emailed (them). The crew chiefs have emailed them. Hopefully, they will change the rules before Gainesville. If not, I guess we will have to live with it.”

Whether or not Jones agrees with the changes the NHRA has made, he understands the goal is aimed at making Pro Stockers safer.

“The NHRA is just trying to make the cars more stable. At the same time it’s going to force us to make some major changes. We’ll see what happens in testing and at Gainesville next week.” Jones concluded.