This Week in Ford Racing: April 13, 2010 Even though this weekend's NASCAR Sprint Cup Series race at Texas Motor Speedway will be the third with the new spoiler, many feel it will be the first real test of what the change will do to the...
This Week in Ford Racing:
April 13, 2010
Even though this weekend's NASCAR Sprint Cup Series race at Texas Motor Speedway will be the third with the new spoiler, many feel it will be the first real test of what the change will do to the race cars. Ford Racing Aerodynamicist Bernie Marcus talked about the new spoiler and what it's designed to do on the track.
CAN YOU EXPLAIN FOR FANS HOW THE DOWNFORCE LEVELS GO FROM TRUCK TO NATIONWIDE TO CUP? "When the new car was created, and during the design process, NASCAR set specific aero targets. They wanted the truck to have the highest amount of downforce and the Nationwide car approximately 20 percent less than the truck and the new Cup car to be approximately 40 percent less than the truck. The thinking behind it from NASCAR's perspective is they wanted the Cup car to be the most difficult and most challenging car to drive. That's how those aero levels got created."
WHAT WILL THE SPOILER DO IN TERMS OF ADDED DOWNFORCE? "It will bring it a little bit closer to the Nationwide car in overall downforce. It will put six, seven, eight percent more on it and also a slightly forward balance shift, which should help because one of the things with the new car was that it tended to understeer or push more, so, hopefully that should address it. But, at the end of the day, you still have to work on the mechanical end and get your balance right, too."
WILL GOING FROM THE WING TO SPOILER STOP CARS FROM GETTING OFF THE GROUND? "The wing was a very low lift aero foil and before the new car got implemented, NASCAR did lift-off testing with both the spoiler and the wing, and, at the time, there was no difference in the lift-off numbers. After the Ryan Newman accident last year at Talladega, NASCAR went back to the wind tunnel and did some more lift- off testing work with the wing and the spoiler and, again, there was very, very little difference. So, really, the reason why the cars fly is not because of the wing, and going back to the spoiler is not going to prevent that. The biggest problem is when the car turns, you get all this air that goes into the back, underneath the rear bumper and the underside of the car, and that just causes the rear of the car to lift."
WHAT IS BEING DONE NOW TO KEEP THAT FROM HAPPENING? "It's an ongoing thing and NASCAR has been very proactive in lift-off testing and development with input from us and the other manufacturers. There's a joint program going on, which will be ongoing for the foreseeable future, to try to come up with ideas to stop these cars from flying. The first product out of the recent lift-off test was putting the 3.5" tall decklid fin onto this car right now. It reduces the lift-off numbers by a significant amount, but, nonetheless, there's going to be ongoing development along the lines of, 'How do we stop air getting under the car? And how do we evacuate the air in such a way that it prevents the car from lifting off?' But, like anything, there are plusses and minuses to it. We tried looking at reducing skirts. For example, you could take the left side skirt off the car and on a counterclockwise spinout it would reduce the liftoff numbers quite a bit because it would let the air get out from underneath the car, but if the car would spin clockwise, you would actually pack more air under the car and the car would be more prone to lifting off. Like everything, it's a compromise and before you implement something, you have to look at all the possibilities."
WHAT DOES THE DECKLID FIN DO? "It's just a vertical fin that runs from the back glass to the face of the spoiler. When you see the car in motion you can hardly see it, but it does help get the side forces back that the car with the wing and curved end plates produced, so that regains the sideforce because with the spoiler alone the car actually lost rear sideforce, which is a stability thing, but the fin does actually bring the sideforce back to where the car was with the wing. It's a cheap thing too because it's just a $2 piece of aluminum."
-source: ford racing