In the summer of 2014 we showed you Motor Trend’s video review of the 918 Spyder at Willow Springs raceway in Southern California. In that video, pro-driver Randy Pobst laid down a 1 minute 23.5 second lap, which was the fastest lap ever on that track for a production car. What they didn’t show in that video is that they also had a 50th Anniversary 991 Carrera on hand to set a quick comparison lap as well. Pobst popped in a 1:28.39 lap. Then, in a follow-up in the next month’s printed issue, Motor Trend showed the lap times in a graphic comparison of speeds on the straights and g-forces through the corners.
Familiar with the track and those times, Jack Olsen (many of you will remember Jack the video featuring his garage and the other featuring his Porsche) wanted to see just how well he could do in his 1972 911 RSR Hot Rod. He brought his Porsche, his camera, his a data logger and his A-game to the track – throwing down a time that lands him somewhere smack in the middle of the two modern Porsches at the same track. Jack’s best lap of his Big Willow home track in his home-built rod is a massively impressive 1:26.88.
After the dust had settled, Jack modified Motor Trend’s graphic display to include his own telemetry track data. As you can easily see, Jack’s car has a substantial advantage through a lot of the lower speed corners, but loses out to the 918 on longer straights where it can stretch its electrically-augmented legs. Most of the cornering prowess is down to a massive 1000 pound weight advantage in the 1972’s favor, and a lot of the 918s speed comes from a 615 horsepower advantage over Jack’s meager 272 ponies. Interestingly, there are very few places where the 991 is faster on track than Olsen’s featherweight track junkie. From the telemetry data, you can easily tell that Jack doesn’t have to slow down as much to make it through the corners, and the light weight (and probably tighter gearing) give Jack an advantage coming off of the corners as well.
Power To Weight vs. New Technology
All of this brings to light the advantage paid by lightweight versus new technology. While the 991 and the 918 have computers going into overdrive (and in the 918’s case, even sophisticated rear wheel steer systems) to help them produce the fastest laps possible, Jack has only his hands grabbing at the wheel, his feet dancing on the pedals, and his brain calculating slip angle and throttle/steering adjustments to keep him out of trouble. The 1972 911 features significantly wider and stickier tires than it did from new, but they are still on par with (or below) the mighty Michelin Pilot Sport Cup II tires found on the 918 (or the Pirelli PZeros on the 50th Anniversary 911).
On a short course like Big Willow, the 918’s advantage is slightly downplayed, as its 3600 pounds is a bit hampering through some of the tighter bits. Were this comparison to have occurred on a track that was a bit longer, had more straights, and was a bit more open, the 918 (and likely the 991) would have trounced Jack. That said, being anywhere in the ballpark of a 918 or even a 991 is certainly something to be proud of, regardless of the track or the extenuating circumstances.
Watch the comparison for yourself with the two videos in this post, and make your own conclusions. First is Jack’s lighteningfast lap in the 1972 RSR Hot Rod above. Below you’ll find the original Motor Trend video we featured last year.
(The 918’s track lap starts at 8:39)
View Comments (4)
" Were this comparison to have occurred on a track that was a bit longer, had more straights, and was a bit more open, the 918 (and likely the 991) would have trounced Jack. "
Keep in mind Willow Springs is one of the straightest, fastest tracks there is. This means Jack's '72 is likely faster at MOST tracks.
Thanks. I agree that it's a mistake to describe Big Willow as a 'short track.' It is very long and very fast -- neck-and-neck with Mosport as the fastest average-speed road course in all of North America.
But…
Willow is unusual among road courses in that it doesn't have a single 2nd-gear turn. In the slowest part of the slowest corner on this track, I'm carrying 61 mph. If Willow had any 5th-to-2nd corners, where horsepower would be a big factor in digging the car out of the proverbial hole, then the 918, 50th-Anniv 911, and 991 GT3 would all have an advantage over me. Their superior outright horsepower and superior power-to-weight ratio of those cars would leave me in their rear-view mirrors. But Willow relies on sustained high speed cornering -- and in that situation absolute low weight (as opposed to power-to-weight) is a huge factor. My lower weight means I don't have to slow down as much as the other cars for the corners, and I can maintain higher cornering speeds through all the sweeping corners. At Willow, that makes a big difference.
So, I'm not going to make any claim that my old car is better than any of the new 911 variants (or the 918) at all. But at the oldest and fastest road course on this continent, my car still has a few tricks up its sleeve.
Jack:
I've long admired your shop set-up as well as your 911. I have not, however, seen a photo of the underside, and am curious about what you have done there. For instance: I was wondering if you had removed the factory undercoating to add lightness? If so, about how much weight would that shave off a stock configuration?
Best,
=rdsieber
No offense to Jack Olsen, but what would Randy Pobst have run after a few get acquainted laps in Jack's car? Cort Wagner drove a friends '70 RS replica with a 2.7L and thinner tires to a 1:26 after just three or four laps. That friend had never broken 1:30 in his car.