NASCAR will test another aerodynamic package – one with even less downforce than the new one in use this season – during the race at Michigan International Speedway on June 12. Pat Suhy, Chevrolet Racing’s NASCAR group manager, recently talked about the impending changes:
On how the new tweaks to the new rules package came about: “It started in discussions between the teams and NASCAR about where the teams are spending their resources; and wondering if this is really an area they want to race in? NASCAR knows that over time, teams have gained aero performance, whether it’s increased downforce or reduced drag, as they spend more and more time in the wind tunnel and as they have worked on the tires to have more grip and more give-up.
“Gaining back more of the downforce they lost by whatever means, jeopardizes all the work that has been done and fans could see racing return to what it was like last year. I think as a problem to solve it was the question of, ‘Well, where are you guys gaining downforce? How come the cars have all this skew in them?’
“The two things that were just done, reducing the number of fans underneath the car and reducing the skew in the rear of the car, were two of the areas the teams had been working in to gain back a lot of the performance that the body change was supposed to eliminate. The teams and NASCAR agreed that limiting those things wouldn’t be a bad way to slow the progress down that path and allow them to focus their resources elsewhere.”
On how the new aero changes affect how the cars drive: “The low downforce package that was tested at Michigan fundamentally probably won’t change things a lot as far as the way the cars handle. The aero balance really didn’t shift very much from where it is today. What is going to probably change is the way the cars behave in traffic.
“Based on what we saw at Michigan, we are going to see corner entry speeds go up, and mid-corner speeds go down. It’s going to put a lot of the ‘driver’ back in the car. It is partway back to the package we saw last spring at Michigan, when they tested the 2015 low downforce package there.
“The speeds were still too high, but I think between the engine changes that happened this year and the fact that they didn’t go all the way to that low downforce package, we are going to see a pretty racy package that a lot of the drivers have been talking about wanting.”
On what types of data his team is providing Chevrolet teams to get them up to speed to adapt to the changes: “We have a vehicle model, a driver in the loop simulator, and we have actually been discussing ways that we can try to help our teams get ahead of it in terms of understanding what engine torque curve and chassis sensitivities look like with this new aero package versus with the old aero package.
“What kind of chassis balance do you need to go along with the aero package? Even though it’s the same aero balance, maybe the chassis needs to be balanced differently? We can’t do it alone and have had great success working with a team or teams to apply our tools to help answer some fundamental questions.”
On whether a recent test at Michigan and during the All-Star race was enough of an examination to make the changes: “I think the truck-arm rule and the fan rule are done for the rest of the season. I don’t really think that needed a lot of testing. That’s just a matter of trying to get some of the gains that the teams have made in downforce out of the car so they are more like what we had at the beginning of the season. As far as the new future aero package being tested at Michigan and Kentucky, I think that is adequate testing. Actually, that is probably more than adequate, based on what we know and how the test went last year on the two packages versus how the racing turned out. My opinion is you might have been able to do it just based on the tire test at Michigan.”
Other ways to reduce downforce: “You get to a point where you can take more downforce off the cars, but there are diminishing returns in terms of the racing quality. There is a sweet spot there. Along the way you can’t stop working on tires. Another thing you could to if you really want the cars to be harder to drive is to put some of the horsepower back in them. There are a lot of things you can do if it’s about making the drivers drive the cars.
“The whole competition committee is coming to grips with the fact that we, as an industry, have to decide our points of difference. Where do we want to race each other? Do we want to race each other with pit guns, or tire fans, or do I want my driver to determine if my car is the fastest?”