Tech Notes: The Intuitive Engineer

The snowmobile industry’s unlikely revolution in the 70s
Dan Gurney
Dan Gurney is one of America’s most successful racers, car builders and engineers.
The first time I heard the term “Intuitive Engineer” was while watching an interview with Dan Gurney on a television motor show. Dan Gurney is perhaps rated as one of America’s finest all around racers and car builders. He won Formula One races with his own car, won LeMans in a Ford GT with A.J. Foyt, and did equally well winning NASCAR road courses and running the Nissan GT sport car team to IMSA Championships. His “Eagle” race cars won the Indy 500 several times.

Gurney was being asked what qualities a racing engineer should have in order to design and develop winning race cars. He explained that the most important quality was not a bunch of college degrees but a keen sense of the best combination of engines and chassis layouts. This intuition combined with the experience to create a package that was clean and efficient in order to make it an effective tool for the driver.

As a trained engineer, I look back to the revolution that the snowmobile industry went through in the 1970s, and it’s astounding to think what was accomplished by a group of dedicated racers. Much of the technical progress was done by “Intuitive Engineers.” Many of them did not have engineering degrees, but they had that strong intuitive sense of what could work. Then they built it, tested it, raced it, improved on it, and with their hard-won experience, built new and faster race sleds. They were not only good racers, they were also great mechanics and fabricators.

■ Try, try again
Because they did not have diplomas, they also had no preconceived notions of what would work or not, so they tried a whole bunch of ideas, and while some failed, some worked out! In the end the packages got faster.

“Ignorance can be a powerful tool if applied at the right time, even out-performing book knowledge” said the talented E.J. Potter. He was famous for drag racing motorcycles powered by large V-8 car engines and actually making them work. He did this while many learned engineers proclaimed him a nut with a death-wish.

The same could possibly be said about today’s top fuel drag racers with their 10,000 HP V-8s powered by blowers and running 85% nitro. Years ago, if you had asked an automotive engineer to design a V-8 engine making 10,000 HP they would have said it was impossible. The less informed drag racers did it anyway, and it’s spectacular now to watch the top fuel dragster go from zero to 300 mph in 4 seconds.
IFS Skiroule racer
Gilles Villeneuve is an example of an intuitive engineer who developed new ideas from his race car-type twin-tracker to his quick IFS Skiroule racers.
Keith Duckworth, who designed the famous Cosworth Formula One engine which ended up dominating F1 racing for 15 Years, had a hard time making engines work to his desire based on his college information. He finally decided that most of the books were out-dated and based on yesterday’s engineering information. He was looking to design an engine that outperformed the latest Italian designs. He decided to go back to “First Principles” and analyze everything from scratch. His motto was: “It’s better to be uninformed than ill-informed.” His engine design was a simple V-8 with four valves per cylinder in a narrow angle and with a large bore and short stroke. Almost all high performance 4-stroke engines today follow the Cosworth formula, which Keith laid out on his drawing board over 50 years ago, without the aid of computer simulation, but guided by a strong intuition as to what he felt was right.

There is a strong parallel from these types of performance-minded people, to many in the snowmobile industry. Decades ago, when the Polaris racers where unhappy with the available Salsbury clutches, they asked the Salsbury engineers to design them a new one that could transfer twice as much power. The engineers at Salsbury said it would be impossible. Since the racers needed a new clutch, and had no idea of the limitations the experienced Salsbury engineers felt was the upper limit, Polaris racers developed their own primary clutch. Not only was the Polaris racer-developed unit successful, it became the new standard for the industry. The Salsbury Engineers were soon out of business.

So how could a bunch of farm boys from Minnesota out-engineer even the factory’s best? They might not have had numerous degrees but they had generations of experience living through the agricultural mechanization age. As a result they were great mechanics, good fabricators, and had strong experience-based intuition of what worked. Add to this a furious pace of constant testing and reinventing, and progress moved at an impressive rate.

■ Examples of the Right Stuff
The development of the independent front suspension is a good example. It was first laid out and formulated with input from Indy Car racer Bobby Unser. He was hired as Race Manager for the Chaparral snowmobile race team in the off-season from his normally busy Indy Car schedule. The first Chaparral IFS racers hit the ice for the 1972 season, but as could be expected they had a number of development problems. Before the new system could be ironed out, Chaparral went out of business. Gordie Rudolph had worked on the Chaparral team, and when he moved back to Illinois he kept on building his own IFS chassis. When Gilles Villeneuve stumped the pro-racers by winning all the Pro-Classes at the 1976 “Kilkenny Cup” in Lancaster, NH with his IFS equipped Skiroule, the chase was on.
The 1977 RXL race team. (left-right Jim Bernat, Steve Thorsen, Brad Hulings, Bob Eastman, Jerry Bunke)
Next, Bob Eastman from Polaris bought a chassis and pieces from Gordie Rudolph and started development of the new 1977 RXL racers. During testing the experienced Polaris racers found that they had to change the design. Gordie’s sled was short and light, so the Polaris boys first stretched the front end out five inches and then installed a longer track. The front end was still too grabby and the skis would chatter with all the extra front-end grip. This was solved by building “Rocker” into the carbide runners, so the grip was concentrated more in the center. A new geometry of the front radius rods solved a tendency of hooking too hard in roll during cornering. By relentless testing, the Polaris boys were ready for the first Pro-Race at Ironwood.

The new RXL sleds totally dominated the competition for the next two seasons and started a mad rush by the other teams to catch up. The new technology was all new territory, there were no answers in text books. What was needed to keep up in this hot race was good mechanics, expert fabricators and experienced race drivers. The guiding force was intuition, expertise and lots of testing and racing. The frantic pace of racing development resulted in new and better snowmobiles as independent front suspension development soon was on every manufacturer’s priority list.
A similar development process took place in the cross-country racing arena. This time it was Gerard Karpik and his brothers who started an intensive testing program to make better long travel suspensions in order to handle the rough mogul tracks. Through constant testing and redesign of components, several key design features were developed by Gerard’s group that today make your sled ride smoothly over rough trails that otherwise would throw and buck you off. All the work by the Karpik brothers was intuition mixed with lots of testing and step by step innovations to make everything work together. There were no books or computer programs to tell them what to do. This was pioneer work.
Gerard Karpik
Gerard Karpik's FAST long-travel M-10 rear suspension revolutionized snowmobile ride and performance.
Great steps forward in technical development of the snowmobile have been made since the early 1970s by “Intuitive Engineers” that built and tested sleds into uncharted territory and won races along the way. Most of those who pioneered the industry lacked an engineering diploma, but held a strong intuition and a hard work ethic.

One last example: Gary Mathers started out as race manger for the Polaris snowmobile team, then moved on to Kawasaki’s snowmobile race team. When the snowmobile division folded, he was moved to the Kawasaki Motorcycle division where he was so successful that he was hijacked by Honda to run their race division. He stayed with Honda for over 20 years while they racked up over 80 national and international championships during his tenure. When he finally retired and was inducted into the AMA Motorcycle Hall of Fame, he was asked by a reporter what kind of personnel he would like to have on his ideal race team, based on his experience with extremes from hi-tech OEM engineers to intuitive down-home racers. His answer was simple: “Give me a bunch of northern Minnesota farm boys and we will beat the world’s best any time!”
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