How GT Cars Race the Goodwood Festival of Speed in the Rain

When it gets slippy on the tarmac, every adjustment matters.

We spent part of last weekend at the Goodwood Festival of Speed. It was a quintessential British motoring event, in that there were loud vehicles, mincemeat pies, properly cordial spectators, and it rained a bunch. Which begged the question: How does one prepare to run of the most infamous hill climbs when it’s wetter than the River Thames?

Across all the classes of vehicles, dozens struggled to find traction. The twin-turbo Ford LM GTE crackled and roared into turn two too hard, only to run off hard and wide, nearly into the hay bale barrier. It sprayed so much muck and grass onto the surface that subsequent runs were halted while track crews attempted to brush the asphalt clean, to no avail. The new Mercedes GT R would later slip in a patch of the leftover debris, while scores of other drivers gingerly navigated the treacherous course.

As the afternoon pressed on and the rain intensified, soaked engineers worked feverishly alongside drivers to give their steeds a fighting chance. Wandering around the paddock with some of the more notorious sports cars, we happened upon Karl Wendlinger, former F1 driver and current Mercedes-AMG stable coach and hot shoe. The Austrian, there to wheel the Mercedes-AMG GT3 race car, mentioned that while they weren’t running for time, rather for demonstration, he still wanted hammer up those 1.16 miles as quickly as possible.

“In any racing circuit, you’re driving on the limit, trying to get all you can out of the car,” Wendlinger told us, but that at the Goodwood Festival of Speed in the rain, “you can’t do that because of safety reasons.” Here, as with a proper circuit, the wet line and dry lines are different, and Wendlinger hinted it took a few practice stabs to find the proper Goodwood wet line. “Once you’re in it, though, you just want to keep it neat and tidy,” he said, adding that steering and throttle inputs have to be far smoother than usual so as not to upset the car or cause it to lose grip.

Technically, there are a few tweaks to the car, though the tires aren’t one. “We trust these Michelins fully. This is what we were running during the recent big victory,” he said, referring to the 1-2-3-4 Mercedes-AMG GT3 finish at the 24 Hours of Nürburgring. Instead, the ESP dial is set somewhere between positions one and five, the traction settings reserved for wet days. “The difference is control,” Wendlinger says. “The lower the number, the more control because it reduces the power.” The engine and gearbox are set to race mode and the ride height of the car is increased, necessary to get the last bit of grip from the chassis. “It’s also bumpy at the top of the hill, nearing the forest, and we don’t want to have our front splitter hitting the ground.”

The rake of the car and that honking rear wing get some adjustments to help ensure proper downforce, though “that’s pretty easy to find in something as precise as this car.” Wendlinger said Goodwood isn’t particularly technical, though it is tricky. “When it’s pouring, the tiniest slip into that wet grass and you’re gone. Not only is it embarrassing, but it’s dangerous, since you don’t have the run-off room here.”

While he was behind the wheel of one of the more modern GT cars to make its way north to the finish line, Wendlinger coveted a historic ride just across the aisle from his car. “Did you see that Alfa Tipo 33?” he asked, gesturing to the gorgeous 3-liter V-8 that campaigned at Le Mans and Targa Florio in the early Seventies. “It’s incredible.” Would he prefer to race that in the rain?

“No, I’m quite happy with the GT3, thank you,” he said with a grin.

Check out our video below of cars running when it was dry, then again during the downpour.