News & Media

NASCAR to teams: Hold line on rear-end setups

September 07, 2012, David Caraviello,

RICHMOND, Va. -- NASCAR will begin inspecting rear-end setups in post-race teardown and has told teams to hold the line on tactics that make the race cars yaw through the corners in the sport's top series.

Sprint Cup teams were notified Thursday in a technical bulletin that NASCAR was reinforcing the parameters of rear-end setups used most effectively by teams like Hendrick Motorsports. Although not a rule change, officials will begin inspecting that area of the cars after events, which was not done previously. Officials also left open the possibility of a rule change on that area of the car for 2013.

"This doesn't change any rules that we've already had," Cup Series director John Darby said. "It reconfirms how far teams can go with their rear suspension setups. Teams have found that, with a car's rear-axle steer, more is better as it helps with aero and gets the cars through the corners faster.

"We are just reminding the teams what the limitations are and that they cannot go past these limitations."

The technical bulletin goes into effect next weekend at Chicagoland Speedway and reminds teams that movement in the rear suspension is limited to a quarter of an inch. Roush Fenway driver Greg Biffle said last month that the issue stems from teams looking for a way to seal air from the bottom of their cars after NASCAR reduced the length of the right-side skirt. Crews now are using rear suspension parts like the sway bar to make up the difference, which can make the car appear to slide on its yaw axis as it traverses the corner.

While some teams like Penske Racing have been hesitant to pursue the setups, others like Roush Fenway followed suit after receiving assurances from NASCAR that the tactic was within the rules. Hendrick was the first team to successfully utilize the strategy, with teams noticing the difference in Jimmie Johnson's car when the five-time series champion won at Indianapolis.

"A lot of people are focused and think it's just Hendrick and big teams that have been working in this area," Johnson said Friday at Richmond International Raceway. "I was in a conversation with Phil Parsons last week, a smaller team. They've been there, they've been doing this for a while. They've adjusted. They've been working on the rule book to get to this point, too. So the fields migrates quickly in certain directions. I think NASCAR is just making sure people understand the parameters so they can regulate in post-race and find ways to make sure no one's going above and beyond."

* Sound Off: Reaction to setup limits

NASCAR Wire Service contributed to this report.