We remember it as “unlimited” and indeed, at the beginning of the Canadian-American Challenge Cup Series in 1966 the rulebook was so thin that there hardly seemed to be any limitations at all. Engines, tires, aerodynamics, materials, dimensions, weights, all were free of restriction. “No Rules” Can-Am cars were the wildest, craziest, fastest road racing machines the world had ever seen—faster even than Formula 1 cars around some of the same circuits. It was a Golden Age for engineering innovation, when designers were free to dream big and build bigger.

Yet nearly all the races were dominated by a single constructor, and it wasn’t the most daringly innovative constructor. Bruce McLaren Motor Racing, aka “The Kiwis” because the team’s founder was a New Zealander, started winning in the series’ second season, 1967, and kept on winning for five years. McLaren drivers were Can-Am champions that year (Bruce himself), 1968 (fellow Kiwi Denny Hulme), 1969 (Bruce again), 1970 (Denny again), and 1971 (American Peter Revson).

McLaren’s dominance became total in 1969. That was ironic. It was the year when series officials nearly doubled the number of races, from the original six to 11. A joke went around the paddocks: the officials wanted to give “the Bruce and Denny Show” more opportunities to lose, so other teams had a chance to win.

The joke was on the others. Either Bruce or Denny came home first in every one of the 11 Can-Am rounds of 1969. For McLaren it was “The Perfect Season.”

An age of revolution

The Sixties. A decade of experiment in culture, politics, the arts, technology. The time of Flower Children and Astronauts.

In motorsports, the 1960s opened with the mid-engine configuration changing the very concept of the cars. Revolution continued with ever-more powerful engines, wider and grippier tires, and downforce aerodynamics combining to burst all previous boundaries of performance. In a time of intoxicatingly rapid growth all through society, free-formula racing fit right in, and the Can-Am offered free expression of that heady spirit of engineering freedom.

Can-Am cars were loud, fast and exotic; many became immortal in the hearts of enthusiasts. Chaparral, innovator of the Wing and Ground Effects. Porsche, first to make Turbocharging work properly in road racing. Ferraris, Genies, Lolas, McKees. A car with a Glass-fiber monocoque, another with one made of Titanium. The Tiny Tire Shadow. One car with four engines, and two with four-wheel drive …

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by Pete Lyons

Photographs: Pete Lyons, The Cahier Archive, Lionel Birnbom

When McLaren’s “Bruce and Denny Show” opened in North America in 1967, it struck native Can-Am racers like a fist in the face. From the very first day at Wisconsin’s Road America in September “The Kiwis” began smashing established norms of organization, preparation and speed. By the time they rolled into Riverside, California, for round 5 of the 6-race series in October, everyone knew their names and wanted to see them in action.

That included a youngster who had been working as a mechanic for a racing school in exchange for driving its cars.

“I raced there in a Formula C car that belonged to the Jim Russell school,” says Frank Zimmermann. “I remember watching the McLaren mechanics, seeing how professional they were, and thinking, ‘Who are those guys? Someday, somehow …’”

Frank’s day would arrive less than a year later. One Friday near the end of August 1968, he found his way to the Los Angeles-area engine shop of Al Bartz. “I wanted to work in professional racing,” says Frank, “and I was told a couple of McLaren’s guys were still at Bartz’s in Van Nuys, finishing up their new Big Blocks.”

The tall, quiet and confident young man walked through a wide open workshop door—it would have been a typically furnace-hot August afternoon—and on the spot found himself undergoing an impromptu job interview with Gary Knutson, McLaren’s chief engine builder. The final question: “When can you start?”
Frank’s reply: “Well, I’m here now.”

He phoned his parents to say he wouldn’t be home. “We worked right on through the weekend and loaded five fresh engines into an old Ford pickup truck. On Monday morning the three of us set out for Elkhart Lake, Gary, Lee Muir and me jammed into the front seat—along with Gary’s enormous early mobile phone, the first I’d ever seen. We drove all night until the middle of the next day, when we stopped in McLean, Texas, to sleep for a few hours. The motel had air conditioning, the truck didn’t.

“I’d never been east of Reno, Nevada. The only race tracks I’d ever seen were all dusty and dry and brown. When we got to Road America I couldn’t believe how green it was, how big the trees were. And how good that Bratwurst barbecue smoke smelled!”

Someone handed the newcomer a uniform. But the name on it was “Beanie.” As Frank laughs, “That’s when I found out I was standing-in for Colin Beanland, who had an eye injury from a grinder fragmentation. I only got hired because I just happened to come along at the right time with the right kind of background and experience.”

The rookie brought McLaren’s road team up to full strength: 10. That included New Zealand drivers Bruce McLaren and Denny Hulme, as well as Americans Teddy Mayer (manager) and Tyler Alexander (crew chief). Frank was assigned to Bruce’s new M8 model with its aluminum Chevy 427 (7.0) V8.

This opening race of 1968 was a rare rainy one, but the outcome was a familiar sight, a pair of bright yellow-orange cars running one-two to the finish, McLaren in “Zimmermann’s car” leading Hulme. The Bruce and Denny Show was off to its second winning season …

More in the current issue!

by Pete Lyons

Photographs: The Cahier Archive, Pete Lyons

Despite massive ongoing investment, Japanese giants Toyota and Nissan have never managed to do what Mazda did in 1991 – win at Le Mans. The success of the Wankel-powered 787B against top-class competition from Mercedes and Jaguar – who had made the world championship their own domain for the last three years – was one of the most surprising results of the latter part of the Group C era.

Mazda first showed up at Le Mans in 1979, failing to qualify with an RX-7. There was another attempt in 1981, with Tom Walkinshaw part of the driver line-up, but neither of the two cars saw the finish. From 1983 onwards Le Mans became a regular part of Mazda’s motorsport programme, working through the Group C2 models 717, 727, and 737. In 1987 there was a breakthrough, Pierre Dieudonné, Mark Galvin, and David Kennedy finishing seventh outright and first in the IMSA class in a 757. And two years later Dieudonné/Hodgetts/Kennedy repeated that result in a 767B.

Englishman Nigel Stroud was in charge of designing the 767 and 787 racers. They were based on a carbon monocoque from Advanced Composite Technology in Derby and powered by a four-cylinder R26B Wankel engine. In 1990 both 787s failed to make the finish, while a 767B did get to the end, albeit in 20th outright.

The Mazda engineers carefully evaluated the disappointing result and took lessons away from it. An analysis of the data suggested that the 787’s ultimate potential was for no more than 352 laps across 24 hours, the same distance covered by the third-placed Porsche 962C in 1990. When it came to setting goals for 1991, Mazda looked at the potential improvement from other teams and calculated that 367 laps would definitely be good enough to win the race.

The underdogs attack

The basic concept of both chassis and engine was solid, so the focus was on eliminating the weaknesses. The engine was tuned up so that it jumped from 630 horsepower to around 700, and a new variable intake system generated 95 per cent more torque in the 6000 to 9000 rpm range, a significant improvement.

The next target was a 10 to 15 per cent reduction in consumption. With a new arrangement of spark plugs, faster and more efficient combustion was achieved. Now there were three spark plugs instead of two, the diameter of which was reduced from 14 to 10 mm.

The team also put some thought into how the car could be driven most fuel-efficiently. For example, by being more patient with the throttle after a slow corner rather than just hitting it as hard as possible. And on the long straights, the drivers weren’t to go over 8000 rpm. A new consumption meter was put into the cockpit so that the drivers were constantly reminded of how important it was to save fuel, and a target of 1.85 kilometres per litre was set. The drivers adapted to the concept surprisingly quickly and were soon vying with each other over who could set the fastest time while hitting the fuel target.

Another big step forward for the 787B was the switch to carbon brake discs. With two chicanes having been installed on the Hunaudières straight in 1990, braking performance had taken on a new level of importance. The carbon discs weren’t just lighter, but had a wear rate around 50 per cent lower. The rear wheels were widened from 17 to 18 inches to allow for better brake cooling, and the team kept a close eye on both temperature and wear. During the race the rear pads could be changed once and the discs not at all, while the front brakes could go through three pad changes and one disc change …

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by Harold Schwarz und Michael Cotton

Photographs: Verdi Kräling, LAT, The Cahier Archive, Sutton