212 MPH Would Have Been Nice

Here’s the secret of driving very fast: It’s really easy.

All you need to do is reapportion all your trust. Do not trust your instruments. At least don’t trust your speedometer (reserve some faith in your temperature gauge). Speedometers are always wrong. Always. Renounce trust in yourself too. Do not trust your reactions. At 200 mph, you are covering nearly 300 feet every second. Your reactions will always be in response to something that happened at least a quarter-mile back.

This story originally appeared in Volume 19 of Road & Track.

Your eyesight will fail you too. Your peripheral vision goes lights out at high speed. Now you’re in a tunnel. There’s a glaring spotlight firing stimulation into the center of your vision, though. Oh, and your brain; definitely don’t trust that thing. That tangle of dendrites evolved at a time when hominids could travel only as fast as their dirty legs could carry them. If your brain isn’t fed reference information in the form of nearby stationary objects, it becomes confused. And then it lies to you. Things appear to slow down as your noodle struggles to compensate for the unusual state in which it finds itself.

Reinvest all of that trust in your car. Yes, that mechanical thing that sometimes fails. And if it’s a car capable of 200-plus mph, it probably fails much more frequently than the average Honda CR-V. Trust that the aerodynamicists did their job in balancing lift versus drag. Trust that the engineers, parts makers, and assembly workers did their jobs properly. But put all of that out of your head, lest you find yourself death-gripping the steering wheel at 200 mph. You want light hands on the wheel. You want to let it writhe in your hands as it reacts to inputs from the front wheels.

Oh, and you did check your tires, right?

Good thing for me that an amiable McLaren tech named Joseph Moore has examined the tires of the 720S I’ll be driving and added about 6 psi to each (up to 39 psi). At 200 mph, the friction of a tire on tarmac generates enormous heat. Generate too much, and the rubber comes apart in spectacular and catastrophic fashion. Increased pressure helps keep the heat in check.

Moore also checked the general fitness of the car, so I had enough faith not to dwell on its condition. That’s good, because I’d flown about 1900 miles to Sun Valley, Idaho, to drive on a closed two-lane public road at better than 200 mph. It does occur to me immediately before the first of my two top-speed runs that I didn’t actually witness these vehicle checks. But hey, you buy the ticket, you take the ride.

An acknowledgment: Outside of the Bonneville Salt Flats, the Black Rock Desert, and the Ehra-Lessien test facility, automotive top speed is a pretty pointless measure. Top speed is the stuff of bench racing. My unscientific survey says precious few supercar drivers have ever come anywhere close to unleashing the maximum capabilities of their precious carbon-fiber missiles. It’s just a number.

But judging by the past decade’s pitched battle for fastest-production-car record, which the Bugatti Chiron Super Sport finally pushed beyond 300 mph, numbers matter a great deal. One might reasonably ask why. What exactly is the point of it all? Where would an owner ever use such speed?

Driving on a public road at half the terminal velocity of the 720S could result in, at the very least, a reckless-driving charge and possibly arrest and vehicle seizure. And most racetracks don’t have straights anywhere near long enough to top out such a machine.

So, again, where would you ever achieve top speed? The answer is simpler than it might seem.

The location is a portion of Idaho State Highway 75 about 10 miles north of the town of Ketchum. The stretch, called Phantom Hill, is within a 10-minute drive of Arnold Schwarzenegger’s 18,000-square-foot vacation home, Ernest Hemingway’s grave, and some of America’s best skiing. For one summer day each year, drivers have four miles of closed highway nestled in the Sawtooth Mountains to finally unleash all of that speed.

I pace nervously in a lay-by off Highway 75, set up as a paddock by the organizers of the Sun Valley Tour de Force event. It’s early, and the air is cool and clear. I’ll be in the second group of cars to run, and I’m unsure of when I should be getting into my 720S to prepare. Mostly I just watch cars from the first group slowing at the end of their runs and pulling into the lay-by, which is crowded with exotic cars, a large tent, and a couple of port-a-potties.

A cheer goes up from the small crowd huddled in front of a large screen. I hear “Yay, Alex!” Curious, I have a peek, and there it is: Someone named Alex Hainer has gone 218.8 mph in a... let’s see... a McLaren 720S. Wow. It’s not until I’m in the car heading to the starting line that I think, “Wait a second. A 720S can’t do 218 mph.” The company lists a top speed of 212 mph.