Pontiac Racing on Aero-Push equation

Aerodynamics are only part of the aero-push equation.

DETROIT, Mich., Aug. 8, 2002 - There is a lot more to the dreaded 'aero push' than meets the eye.

Any talk of aerodynamics generally leads to an exclusive focus on the bodies that cover a stock car. But, according to Pontiac crew chief James Ince and GM Racing's Terry Laise and Doug Duchardt, the competitive formula that applies to Winston Cup racing involves a number of other variables - all of which play an important role in the end-result on a Sunday afternoon.

Thoughts From James Ince, Crew Chief, No. 10 Valvoline Pontiac Grand Prix:

WOULD YOU LIKE TO SEE THE CARS IN THIS SERIES BE LESS DEPENDENT ON AERODYNAMICS? "I would like to see us be a whole lot less dependent on aero and I know NASCAR is working on that. The tire is the reason that it has become so aero-dependent. Goodyear wants us to get back to running big springs in the car - and that's a big issue for all the side loads in the corners - but, the part that they don't understand is for us to go get the mechanical grip that we need to go get we have to run the soft springs and we have to bring the aero into play. If we went back and got softer tires on these race cars it would put us back in a situation to where they wouldn't be near as aero-sensitive.

"The other thing that we face right now under this scenario is that crew chiefs have basically been eliminated at this point. Any 'schmoe' can call a Winston Cup race and be competitive right now because there isn't a whole lot of strategy that goes into one of these things. Now, you can take two tires and stay out because these things last so long. It has taken all of the racing out of the racing. It's become very frustrating for us.

"If we were on softer tires, I believe aero wouldn't be as big of an issue. Naturally, we would still work on that awfully hard, but the tire is what has created all of this.

"If we would lose 25 percent of our overall downforce we've got now, it would also put the driver back into the equation. Right now, the cars are so equal that you just can't do a whole lot. They're all driving just as hard as they can and everybody is equal. If you got rid of 25 percent of our downforce you would put the driver back up on the steering wheel. We wouldn't run the aggressive setups that we run now because, without the downforce, you can't run those setups. It would just make the racing a whole lot better."

Thoughts From Terry Laise, Lead Chassis and Aerodynamics Engineer, GM Racing:

AERODYNAMIC SENSITIVITY APPEARS TO HAVE BECOME MORE OF A FACTOR OVER THE YEARS IN NASCAR...WHAT IS THE REASON FOR THAT? "Historically, over the past number of years, whenever there has been an issue with competitive balance the guy behind has been given more aero. The guy ahead has not had any taken away. That continues to go on, so the total downforce has gotten higher and higher. As the downforce gets higher and higher we become more and more dependent on those aerodynamics at the expense of becoming less sensitive to chassis. The tire gets harder because of an increased load due to aero and that leads to less grip, if they take the aero away. That is sort of what we have gotten ourselves into."

WOULD A SOFTER COMPOUND TIRE HELP ELIMINATE THE AERO PUSH WE SEE IN NASCAR WINSTON CUP RACING? "It might. But, you could leave (the compound) where it is and get rid of the aero push. There are a couple ways to go about that. But, that would require a decrease in total downforce, and the thing you get with less downforce and the hard compound tire is that the cars slip around a lot more because of a lack of grip in the tires. A softer compound would obviously give you more grip, but then you increase the amount of wear in the tires because of the greater grip."

IS THERE AN OPTIMUM POINT SOMEWHERE IN THAT EQUATION WHERE THE RELATIONSHIP BETWEEN AERO, CHASSIS AND TIRES WOULD LEAD TO THE BEST OVERALL PACKAGE - BOTH FOR COMPETITORS AND FANS? "I'm sure there is, but it would take a concerted effort to find it. Right now we are very aero-dependent and because of that, people have learned to work with the package we have, better and better. We've developed a better understanding of what the car wants in terms of maximizing its aero performance.

"The way these cars are configured (from a suspension standpoint), they can reach a point where they have a great deal more downforce in the rear than they have in the front and that is the aero push. It used to be that our cars were balanced differently. We ran different kinds of chassis and setups. The cars were balanced in such a way that when two cars ran together, the car in front lost a critical amount of rear downforce, while the impact on the car behind wasn't near as bad. It was the opposite of the way it is now. If you remember, under that scenario it used to be that a guy would get up under a guy, make him loose and pass him. Now, we've reached a point with the setups that we run that that just doesn't quite work.

"The Brickyard 400 was probably the first race where the aero push really showed up because those were really fast, flat corners. Typically, it had been the tunnel-turn at Pocono because that was a very fast straightaway into a flat turn. But, Indy had two corners that had flat, very high-speed entry corners and that is where the aero push started to show itself."

Thoughts From Doug Duchardt, NASCAR Group Manager, GM Racing:

WHY HAVE AERODYNAMICS BECOME SUCH A DOMINANT FORCE IN NASCAR WINSTON CUP RACING? "It is the nature of racing. Every racing series is that way. Aero gains just continue to happen.

"The over-riding influence in how the car runs is at the aero platform, so you do whatever it takes to get the aero platform to make maximum downforce, no matter what compromises it causes in chassis setup. That becomes more important that the springs, the shocks and your mechanical grip at tracks like Pocono, Indy and Michigan.

"Back in 1998 when Jeff Gordon won 13 races we were racing with an amount of total downforce that is probably close to 60 or 70 percent less than we have now."

-gm racing-