FRANKFURT, GERMANY—As the twin forces of efficiency and safety change the vehicles around us to meet the needs of the 21st century, there’s not much day-to-day relevancy in how fast a car can go on a straight and flat enough road.
Just about any new car sold today will happily cruise 20-30mph (30-65km/h) faster than even the most permissive speed limits outside a few stretches of German Autobahn. Even on the derestricted stretches, you might struggle to find yourself traffic-free long enough to exercise a supercar up to 200mph, and anything beyond that has always been more of an academic exercise than anything else. Unless your name is Andy Wallace, that is.
The British racing driver’s initial big result came at Le Mans in 1988, the first of many in a success-filled career racing sports prototypes. That first win was back when the Mulsanne Straight really was flat-out for 3.7 miles (6km), which meant going a little faster than 247mph (398km/h) for most of the 394 laps it took to win that year. So it shouldn’t be surprising that Wallace has gotten the call when someone needed a production car tested at that kind of velocity. He was behind the wheel of the record-setting McLaren F1 at Ehra-Lessien in 1998 and then again with an even faster Bugatti in 2007. That association continues to this day, most recently experiencing the 305mph (495km/h) Vmax of the Bugatti Chiron Super Sport 300+.
He told me that things are actually pretty calm as long as you’re in the first 95% of the Bugatti’s speed envelope. “Up up to about 450km/h (280mph), everything’s absolutely fine. When you start to go past that, you have to be really, really careful with your inputs. Partly because of all the inertia in the wheels; they have this gyroscope effect. You definitely feel like you’ve lost some of the influence of where the car goes,” he explained.
[Y]ou have to be really, really careful with your inputs.
As you might imagine, it requires a lot of concentration. “Yeah, you’re monitoring everything and you’re trying as hard as you can to stay where you are. You need to take the information and feel comfortable with it. And it’s quite difficult to do,” he told me. “There was quite often a crosswind, especially down the far end [of the track]—you have these wind socks, so you can see that there’s a wind across there. And before you get there, you’re already anticipating that you’re going to get blown that way. All of this is happening at the top speed, which is over 136 meters a second [446 feet per second]. So to try and sort of put that into perspective is a kilometer every seven seconds, it’s really coming at you fast.”
Perhaps the biggest difference between high speeds in 1988 and high speeds today are the tires, Wallace told me. “Our top speed was 398km/h in 1988. In those years, we couldn’t run radial tires, we had to actually use cross plys for Le Mans. But when a cross ply fails, it unravels; the first revolution takes the wing off. So everybody was worried about that, and that was close to 400(km/h). And to me that felt really, really fast. Little did I know that some years later, I would be in the Bugatti almost a hundred kilometers an hour faster,” he said.
The Pilot Cup 2 tires on a “regular” Bugatti Chiron are already rather extreme compared to just about any other tire you or I might encounter. But something even more special was required to break 300mph. “We kept the same belt on the tire, but we decided to reinforce it so it can handle up to seven tons of traction, and around 5,000 Gs,” explained Benjamin Vilpert, the Michelin development engineer responsible. It goes quicker than a Formula One car, with a car that’s much bigger and much heavier. And it’s still a road legal tire, right? That’s a big, big thing; still keeping it road legal.”
Whether the customer Super Sport 300+ cars will come with the same spec tires remains up for discussion. But when you consider that 300mph is a significant occasion even at Ehra-Lessien with Wallace driving, a “yes” seems unlikely.