Testing has moved from the circuit to the mountain, with the first rounds of foreshortened runs on the closed course providing invaluable, if limited, feedback for team. The challenges inherent in readying yourself and your car for a 12-mile sprint up a 14,000ft mountain come thick and fast, with the sheer logistical struggle ever present. “The interesting thing about preparing for Pikes Peak,” Zwart says, “is that we practice it in thirds – bottom, middle and top – and the only time you put all three of those sections together is on race day.”
This means that the variables that the competitors must contend with and account for are numerous. Temperatures vary hugely from top to bottom, so the performance of tyre or engine can be radically different from one elevation to the next. Increasing altitude also plays its part, affecting aero, induction and oxygen levels for the drivers themselves.
“We make our first practice run at 5:30am and are done by 8:30am when the mountain opens to the public,” Zwart explains. “We’re running as the sun comes up then, but might start the race at 10:00am or even 11:00am when the temperatures are completely different. At the bottom it’s regularly 75 or 80 degrees but it can be 45 or 50 at the summit. We’re climbing almost a mile up a mountain and things can fluctuate up there. I always describe Pikes Peak as a living organism.”
For Zwart, another hurdle comes in the form of the car itself, a significant departure for the veteran racer who has honed his skills in far more analogue cars over the years, often purpose built for Pikes Peak with brutal boost and downforces packages to match.
“I come from the old school – no ABS, no traction control, none of the modern technologies that race cars depend on today – so for me the biggest challenge is using those things to my advantage at the highest level, rather than just relying on them for a little more traction or stopping power. I’ve got to really maximise the tech and that’s a fairly steep learning curve for me.”
It’s been five years since Jeff raced at Pikes Peak, but this will be his third consecutive year coaching the GT4 Clubsport class for Porsche Motorsport. The act of breaking down the mountain into stages, and articulating his own physical and mental processes, has kept him sharp and familiar with the course. And he already seems to be gelling with the 935: “It’s the most comfortable race car I’ve ever driven. It’s already so neutral and my engineer has found fantastic balance in the set-up. The combination of the turbo, the bodywork and the Motorsport chassis is wonderful. It’s just a case of discovering the limits for me now. Getting beyond exploratory speeds to competitive speeds, which are two very different things!”
And competitive it will be. The Time Attack class into which the 935 has been entered will also see two 911 GT2 RS Clubsport cars take on the mountain, one driven by David Donohue, son of legendary 917/30 Can-Am champ Mark Donohue, and the other by David Donner, America’s last outright winner here and part of the family synonymous with the event since its earliest days.
Next in the schedule for Zwart and his team is more testing prior to race week at the end of the month, which will include final runs up each stage of the mountain before Thursday’s qualifying and the event itself on Sunday, 30 August. “It’s going to be a very interesting week,” Zwart suggests, “because I don’t know enough about the car yet to make a prediction about where we’ll be. I’m so fortunate that Bob Ingram has let me drive his 935 – one of just 77 – up one of the trickiest mountains in the world and I’ve honestly never enjoyed driving a car so much there. I’m just really curious to see how everything pans out!”
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Photos action shots: Rupert Berrington
Photos static shots: Jeff Zwart
