Tales of the tape: Early adventures in F1 data logging

The scene: The 1978 Brazilian Grand Prix. The practice session finishes, and Goodyear engineer Dr. Karl Kempf bolts straight to the toilet at the back of the garage in Jacarepagua’s pitlane. Once he sits down, he won’t be leaving for a while.

If you happen to be reading this while you’re eating, there’s no need to put your lunch aside. This isn’t what you think. The toilet seat is closed. The plumbing hasn’t yet been connected, although the bathroom-y tile work on the walls has been finished. This space is Kempf’s office for the weekend, and the work he’s doing will help change the way race cars are set up forever.

Kempf’s path from his native Ohio to being seated upon a partially-constructed toilet in Rio de Janeiro was a complicated one. As a kid, he was obsessed with Formula 1. “I don’t know how a kid in Ohio got interested in Formula 1 racing and not NASCAR and not IndyCar, but I’ve got pictures in my grade school notebooks of Jochen Rindt and Jackie Stewart and all sorts,” he tells RACER. “It was weird.”

A mathematician by training, Kempf (main image) interned at Goodyear in Akron while working on his PhD, but the “Sliding Doors” moment came sometime later when he decided to take a break from working on his thesis to travel to the Canadian Grand Prix as a fan. While walking along a fence behind the pits, he encountered a familiar figure on the other side of the fence walking in the opposite direction.

“We look at each other, and he says, ‘Karl!’ and I say, ‘Dennis!’” Kempf recalls. “It was the guy that I did my internship with at Goodyear. And he said, ‘What are you doing?’ I said, ‘Well, I just finished my PhD and a post-doc. I’m just writing up a bunch of stuff. What are you doing?’ He said, ‘I just got promoted. I’m heading to England. I’m now the head of the Goodyear International Racing Division.’ And I said, ‘Oh, wow, cool.’ And about 30 seconds later, he said, ‘You know what? You should come with me.’ Took me maybe two nanoseconds to decide.”

They continued the conversation in the Goodyear hospitality tent, where Kempf’s mission was laid out.

“He said, ‘We’ll start you off in beautiful Wolverhampton where the office is,’” Kempf says. “‘But the job is not to sit in the office in Wolverhampton. Let’s build a data acquisition system and let’s get it on all the Goodyear cars. We need to actually measure what’s going on and bring some science to the art of motor racing.’”

Kempf got to work, and six months later he’d come up with an initial package that measured areas including suspension deflection, spring and damper loading, steering, throttle position, brake position, engine revs, lateral Gs, fore/aft Gs, and yaw rate. An updated version also measured tire temperatures.

Kempf making magic happen on a toilet in the back of the garage at Jacarepagua during the 1978 Brazilian GP. Motorsport Images

“It took six months to make it, and about three months to refine,” Kempf says. “Because it turns out that a Formula 1 car with all that rotating metal in the engine… the vibration spectrum makes it really hard to get a measurement package to live on a race car for a long time.”

The next task was to sell the teams on the system. “There were three camps,” Kempf says. “There was one camp that said, ‘That’s pretty interesting, but don’t call us, we’ll call you.’ There was another camp that said, ‘Oh, let’s do some measurements and see,’ and they maybe did one or two runs. But the people who really got into it were Derek Gardner (Tyrrell) and Mauro Forghieri (Ferrari).

“Mauro was a superb engineer. I can’t tell you how good he was. He was particularly interested in it because [Niki] Lauda was the most analytic driver since Jackie Stewart. There were times we’d go to test, and we’d have to literally let the car run out of gas to get him out of the thing.

“He understood that the more he drove, the more comfortable he was in the car, the better data he could give us. He was super-duper at setting up the car. When we raced, we used to spend Friday setting up for qualifying and qualifying well, and if we were on the front row, we spent all day Saturday while everybody else was scrambling for their qualifying times setting the car up to race on Sunday, which means when the race started, we — pardon my British slang — pissed off into the distance.

“And, of course, Gardner was interested, and Goodyear was interested, because secret to everybody, they were working on the six-wheel car. So, I spent most of my time at Ferrari and at Tyrrell. Had a great time with Ermanno Cuoghi, Lauda’s mechanic — we had lots of interesting discussions about where to mount the electronics! Ermanno didn’t want any extra weight on the car…”

Cuoghi’s trepidation was somewhat understandable, because even by the standards of the day, the data logging system was a significant addition: aside from the sensors and other bits that were required to make it all work, the data itself was recorded to a standard cassette tape, which meant fitting a tape recorder to the car. One cassette could hold a full race worth of data, although the sample rate had to be reduced compared to qualifying.

“First, the sequence was a tape recorder on the car recording data so that I could take the tape back either to the pits or to my office and do the tapes,” Kempf says. “Then we got clever enough to have the computer at the track so that I could interpret the data at the track. And then we started to get smart enough to computerize it, and once we had the computer on the car, we said, ‘Well, hold on… the obvious next step is to do some car control.’”

Lauda’s analytical approach made him the perfect guinea pig for those early data-driven forays into cockpit adjustments.

Lauda’s analytical approach was a huge asset during the development of computerized data. Unlike the Tyrrell, which had the data logging equipment mounted in the sidepods, Ferrari’s was located in the rear of the car. Rainer Schlegelmilch/Motorsport Images

“Someplace or other, there’s a Ferrari 312T or a 312T2 — I can’t remember which one we tried it on first — with a couple extra knobs on the dash,” Kempf says. “Now, if you change the brake balance front to rear of the car, you can alter the handling quite dramatically, right? And of course, the anti-roll bars adjustment is one of the things that you change the handling of the car with, too. So we would find in a 70-lap race at Long Beach, Lauda might adjust the car 120 times.

“The measurements led us to the conclusion that you never go through the same corner twice. You go through the first corner on the first lap, you go through the first corner on the second lap, but the car’s a little lighter and the tires are a little older. You may be trying to pass somebody, then you go through the first corner a third time, the track may be a little oilier or a little more adhesive, because rubber’s been laid down. If you think about it for a minute, at the micro scale, if you’re really trying to tune the car, you never go through the same corner twice.”

That revelation helped plant the seed for another innovation that would take shape in the very near future, but it would do so without Lauda’s involvement. The Austrian’s relationship with Ferrari had soured during 1977, in part due to his decision to pull out of the ’76 Japanese GP after two laps because he thought the monsoonal conditions were unsafe, and although he won the ’77 championship — his second for the Scuderia — he was off to Brabham the following year.

From Kempf’s standpoint, Ferrari itself was out of the picture, too — the team switched from Goodyear to Michelin at the end of that season. And at the same time, Kempf was questioning his own place at Goodyear due to a change in management. After weighing his options, he decided to pass on an opportunity to link up with Harvey Postlethwate at Wolf (“I think at that point Harvey and I were the only two PhDs in Formula 1,” he says), and instead work directly for Tyrrell.

At the time, Tyrrell was still wrestling with its innovative, but inefficient P34 six-wheeler — a concept with problems even beyond the reach of the latest breakthroughs in data collection.

“Even detailed measurements on the six-wheeler couldn’t save it,” Kempf says. “It was incredibly difficult to set up. Of course, one of the original arguments was to reduce drag, but if you take the small front wheels out of the airflow, you’ve still got the humongous rear tires in the airflow. And tuning the front suspension turned out to be really difficult.”

The project was parked in 1978, and at around the same time, Gardner — father of the six-wheel concept — also left the team to be replaced by Maurice Philippe.

It’s at this point that the story takes a short deviation from most of the history books. The accepted wisdom is that active suspension in Formula 1 was pioneered on the Lotus 92 in 1983, four years before Ayrton Senna scored the first win in an active suspension Lotus at Monaco in 1987, and nine years before Williams smoked everybody with the FW14B in 1992. On all of those counts the books are correct, although they might deserve a new footnote. Lotus was indeed the first to race with active suspension — but Tyrrell might have been the first team to develop it.

Kempf and Tyrrell designer Derek Gardner crunch some numbers from the six-wheeled P34 during testing at Silverstone in 1977. In this case, they weren’t going to find many answers – the six-wheel experiment was shelved soon thereafter. Motorsport Images.

“I’m not sure anybody knows very much about this,” Kempf says. “But when Maurice came, he had a drawing for Brian Lisles, who at that point was sort of the chief field guy. So Brian and Maurice and I got our heads together. Maurice showed us a drawing, and he had essentially devised a suspension mechanism with what looked like a cannon ball hanging off the middle, so that when the car went around the track, the cannon ball would move under the centrifugal force and adjust the camber of the suspension.

“Brian and I were convinced on one hand that it was a great idea. But on the other hand, we thought that having the cannon ball swinging around, the frequency response would be way too slow. So Brian redesigned the suspension.”

RACER reached out to Lisles, who confirmed Kempf’s recollections. “The system started out as a purely mechanical system, which then morphed into an electronically-controlled, high-pressure hydraulic system,” he said.

Kempf continues the story.

“I got some Moog valves; figured out the math and the electronics, and we built what I believe is the first active suspension car. It controlled camber. And when I designed the electronics and did the math, we could literally tune the handling of the car with two knobs, one for the front and for the back. We could turn an understeering car into an oversteering car, etc. That helped us discover some aerodynamic difficulties with 008 that went into 009.”

If Tyrrell cooked up a functioning active suspension system four years before anyone else, it’s reasonable to ask why we’re not talking about Didier Pironi as the 1979 world champion. The answer is simple: Tyrrell was smart — but Lotus was smarter.

“’Chunky’ [ED: Lotus boss Colin Chapman] beat us to the point,” Kempf says. “Obviously Chapman was smarter than we were. We were working on camber; Chapman was working on download on the tire, which is infinitely more important than the camber angle of the tire.

“So, the first ground effects car came, and we put the active suspension on the shelf. Obviously, if I give you the choice between putting together a little extra fiberglass under the car, or hooking up a hydraulic pump to the engine, putting a hydraulic accumulator in, running hydraulic lines around to the Moog valves with moving suspension with two computers on the car… you pick the fiberglass, particularly because the fiberglass would make you go a little faster than the active suspension. So, the active suspension went on the shelf. I’m not sure exactly what happened to it after I left. But that was the first active suspension car, and it was worth three tenths a lap, which generally means you kick everybody’s butt immediately. But the ground effects car was worth half a second a lap. So you build the ground effects car, right?”

Some of the data logging equipment used by Tyrrell during 1979. Actually analyzing the data that came off the car required another desk full of equipment. Motorsport Images

While that active system never made it from the test track to deployment in a grand prix, it’s worth taking a moment to consider how far the general understanding of — and ability to manipulate — vehicle dynamics had come in a short amount of time. Just three or four years earlier, teams relied on a stopwatch and driver feedback. Now, there were computers mounted in the cars controlling the suspension. That leap had gone hand in hand with the strides made in how the data was collected and analyzed.

“The sequence of using the data to set up the car got better and better as we went from tape at home base, to tape in the pits, to the computer on the car actually analyzing the data as it was collected,” Kempf says.

“So, rather than having to take the tape out, go into the pits, sit on the toilet in Brazil and interpret the data, we could take the tape out and get the suspension moving, get the roll, get the attitude of the car relative to when it was sitting in the pit… So I didn’t have to do a whole lot of computing off the car.”

But Formula 1 was changing. Ground effect didn’t only kill off Tyrrell’s shot at active suspension immortality, it reinforced the gradual shift in emphasis from mechanical downforce to aerodynamic downforce. For a self-confessed “suspension guy” like Kempf, that meant two choices: learn about aerodynamics, or take pride in the championships he’d helped Ferrari win and the innovations he’d helped cook up at Tyrrell, and draw a line under F1. He chose the latter.

“I’m sitting there thinking, ‘OK, do I go back to school to learn aerodynamics?’ And I got a phone call from the guy in England that I bought computer hardware from,” he says. “He said, ‘I just had some guys in the office. They’ve got this special effect that they want to do at Pinewood Studios, but it takes computer control to do it. Of course I could sell them computer stuff, but they have no idea who’s going to write the software. And we know you do really weird ****, so we thought, do you want to talk to them?’

“So, I took a couple days off and flew into Heathrow and drove up to Pinewood. And to make a long story short, I left Formula 1 racing, and went and worked at Pinewood Studios to make Christopher Reeve fly in the Superman movies! We won the Academy Award for special effects for the first one, which was a nice addition to three world championships.”

Kempf is still active — his time at Pinewood was followed by a stint at McDonnell Douglas designing robots to rivet aircraft together and work on control systems for space stations, after which he moved to Intel, where he remains as a Senior Fellow to this day.

It’s all worlds away from a Brazilian toilet, but he takes immense pride in the work done four decades ago whose DNA can now be found on every engineering screen in every pitlane in the world.

“You can go through the literature and you can find at least 50 people who claim to be the first people to take measurements on race cars,” Kempf says. “I’m sure General Motors and Ford had instrumented passenger cars. I think our claim to fame at Ferrari and Tyrrell was that we were the first ones who did it on a regular basis. Every time the car turned a wheel, whether it was a test, whether it was qualifying, whether it was racing, it was being measured. And we actually used it to set up the car, in qualifying, and we actually used it to redesign the car. So our claim is, we’re not the first to measure; we’re the first to actually use the measurements on a regular basis.

“If you think of the brilliance of the people who were involved… I mean, it’s difficult to tell you how good of an engineer Forghieri was. Gardner… Philippe… And Lauda…good lord. Come on. How could we not do all these things, working with these guys?”

Story originally appeared on Racer