That understanding requires a driver to understand the technical switch from a road course setup to an oval setup. On an oval, the car has a very asymmetrical setup where the car wants to turn left by itself. On the straightaways, the drivers have to hold the steering wheel at an angle toward the right because of this.
The right side tyres are ever so slightly bigger than the left side tyres to help the car turn and the cambers on the left side tyres are positive while they are negative on the right side tyres. After all of that initial setup work is done to make the car go fast in the corners, it’s up to the race engineer to make sure that the driver can not only drive the car but to make sure that they’re feeling what they’re supposed to feel, and that’s where race engineer Olivier Boisson comes in.
“We’re looking at the data to make sure we don’t see anything on the steering wheel that indicates to us that the car’s a bit loose, a bit hard to drive, but the car was pretty safe to go out,” Boisson said.
When Grosjean is going into a corner on a road or street circuit, those corners are usually very quick duration corners where a driver will enter, apex and exit usually within a couple of seconds. However, a corner on an oval is usually a longer duration corner, taking up a much larger percentage of the lap, especially at Gateway.
Complicating things at Gateway is that both sides of the race track are very different. Turns One and Two require braking, are much tighter and banked at 11 degrees, while Turns Three and Four have a much larger turning radius with only nine degrees of banking. A car with a great setup can go flat out in Turns Three and Four in qualifying, but a driver must learn to trust the car.
That means every little setup change matters that much more on an oval, especially with the margin for error shrinking as the speeds increase. As Grosjean did more laps, he was able to feel what the car was doing and was able to gain confidence to drive an oval as it should be driven, and his feedback as the day went on helped the team make changes to help increase that confidence.
“You can do so many [setup] changes on the oval,” Boisson said. “Let’s say you change cambers and you can change toes or springs on the car. You don’t change the front or the rear, you change one corner. It’s like a right front spring or right rear spring. So you can make many changes because you change one corner at a time, not necessarily the whole car [at once].”
A driver can have some after-effects when they finish their first run on an oval. Grosjean was dizzy after getting out of the car for the first time, but that’s normal for a driver who has never driven an oval before and hasn’t had his body adapt to the G-forces.
Grosjean’s only scary moment during the test was a half-spin coming off of Turn Two. While following another car, Grosjean had some understeer but then the car just gripped the track suddenly as Grosjean kept turning the wheel and the car spun but never hit the wall.
“He was like, ‘Wow, that was interesting.’ And we just went on with our day,” Boisson said. “I was like, ‘Do you want to get out of the car?’ And he was like, ‘No, I’m cool.’ And yeah, that was it.”
“It’s pretty cool to see a guy like him having fun and enjoying the oval,” Boisson said. “It’s definitely different for people from Europe, but once you get used to it and you understand it, it’s very technical and very challenging and pretty fun.