1972 — The 917/10 Turbo and the Fall of the Papaya Empire

By 1972, the Canadian-American Challenge Cup was no longer simply a battleground for engineers and daredevils — it had become a crucible. For six straight seasons, McLaren Cars had rewritten the limits of what unrestricted racing could be. They had built the fastest machines, fielded the most complete driver lineups, and maintained a discipline that bordered on military precision. But dynasties age, machinery plateaus, and innovation does not sleep. Beneath the surface of the papaya empire, a new storm had been building. Porsche, having observed, learned, and admired from a distance, arrived with the most sophisticated machine Group 7 had ever seen: the Porsche 917/10 Turbo, a twin-turbocharged evolution of their Le Mans prototypes. With it came a philosophy radically unlike McLaren’s: forced induction, aviation-grade materials, and handling shaped by computational analysis rather than intuition.

McLaren entered 1972 with the M20, an evolution of the M8 series but no revolution. It was lighter, carried a more centralized mass, and had a monstrous 509 cu in aluminum Chevrolet V8. On paper it was the most advanced conventional Can-Am car ever constructed. But next to Porsche's wind-tunnel-sculpted spyder — wide, short, and clawing the road with brutal downforce and turbo thrust — the M20 suddenly felt old. The papaya team, still carrying the torch of Bruce McLaren, arrived with quiet professionalism. Peter Revson had left to pursue Formula One. Denny Hulme remained the lone standard-bearer. And the paddock sensed that the balance of the series had finally shifted.

At the center of Porsche’s assault stood Mark Donohue — engineer, perfectionist, and one of the most precise drivers of his era — paired with Penske Racing’s immaculate preparation and discipline. The combination of Porsche’s technical might and Penske’s execution created the most formidable Can-Am program ever assembled. But fate altered the script before the season even began. Donohue suffered severe injuries during pre-season testing at Road Atlanta, leaving him sidelined indefinitely. Into his place stepped George Follmer, a fierce and underrated competitor who suddenly found himself entrusted with the most sophisticated racing weapon ever built.

The 1972 season would have ten rounds scheduled but ultimately contested nine after Mosport’s cancellation. For the first time since 1966, the papaya cars arrived not as presumptive champions but as challengers. The orange empire stood tall — but the turbocharged revolution was already roaring behind them.

Round 1 — Road Atlanta (July 9, 1972)

Road Atlanta was the perfect stage for the 917/10 Turbo’s debut: elevation changes, corner combinations demanding balance and power, and long straights begging for raw acceleration. Follmer, thrust unexpectedly into Donohue’s role, showed immediate mastery. In qualifying he shocked the field by capturing pole, exploiting the Porsche’s violent mid-range boost to rocket out of the esses like no naturally aspirated car could follow. Hulme qualified second in the M20, nearly a full second behind. Jackie Stewart’s Lola T260 anchored third, the gap already hinting at the power chasm that defined the season.

When the race began, Follmer launched perfectly, blowing through Turn 1 with the 917/10 squatting under boost. Hulme gave chase, but even early on it was clear the Porsche’s acceleration was untouchable. At the end of every straight, the turbo machine stretched another few car lengths, as if pulled by an invisible force. Stewart held third but quickly lost ground as the pace intensified. The McLaren M20, despite excellent mechanical balance, simply lacked the explosive thrust required to remain competitive.

Mid-race, the Porsche’s one vulnerability revealed itself: turbo lag. Follmer had to time throttle inputs with precision, catching the violent surge as the twins spooled up. Once unleashed, though, the car was a missile. Hulme capitalized on Follmer’s occasional hesitation to close in — especially in the technical sections — but he could never sustain the attack once the straights opened again. The crowd could see the paradigm shift in real time: McLaren’s era of naturally aspirated supremacy was ending.

Traffic complicated matters further. Road Atlanta’s narrow ribbon of pavement forced bold maneuvers as backmarkers were lapped early and often. Follmer sliced through with razor efficiency. Hulme, still nursing residual nerve sensitivity from past injuries, navigated with characteristic caution. Stewart retired with mechanical trouble, leaving the Porsche and McLaren even more clearly isolated at the front.

In the final laps, Follmer increased his pace dramatically, pushing the 917/10 into sector times no other car touched all weekend. Hulme settled into second, preserving valuable points but visibly aware that the new era had arrived. Follmer crossed the line with Porsche’s first official Can-Am victory — a win that confirmed not just speed, but inevitability. The crowd sensed it. The paddock knew it. The papaya dynasty had finally met its match.

Round 2 — Mid-Ohio (July 16, 1972)

Mid-Ohio’s tight, technical layout provided the grid with its best early-season chance to contain Porsche’s power advantage. Here, raw thrust mattered less than traction, mechanical balance, and efficiency through traffic. The McLaren M20 excelled in such environments — and Hulme made clear in qualifying that he was unwilling to surrender the season without a fight. He snatched pole from Follmer by mere tenths, using the M20’s superior low-speed agility to compensate for Porsche’s monstrous straight-line speed.

When the race began, Hulme launched perfectly. He built an early gap through the first sequence of corners, exploiting the M20’s traction and finesse. Follmer, carrying more boost lag here than at Road Atlanta, struggled to attack in the early laps, often trapped behind the M20 during the slowest transitions. For the first time in 1972, the papaya car looked competitive — even superior — in race conditions.

Mid-race, the balance shifted dramatically. As the track rubbered in and fuel loads decreased, Follmer began timing the turbo better. He adjusted his driving lines to square off corners, setting up boost earlier and using Porsche’s stupefying acceleration to launch down the straights. Lap by lap, the gap tightened. Hulme defended fiercely, using every ounce of experience to maintain track position, but the inevitable arrived just past half-distance: Follmer caught Hulme in the back straight draft, spooled up the turbos, and blasted past with a differential that felt almost unfair.

Once ahead, Follmer dictated the tempo. The Porsche became more planted as the race went on, its boost delivery smoothing into a refined — but still terrifying — thrust. Hulme chased with everything he had, setting some of his most committed laps of the season, but the natural-aspirated engine could not reclaim what the turbos so effortlessly produced.

Traffic added late drama. Several backmarkers forced Follmer into defensive lines, allowing Hulme to close the gap to under two seconds. Spectators hoped for a miracle — but the Porsche’s power erased any lingering tension. In the final laps, Follmer reasserted control and crossed the finish line with another decisive victory.

Hulme finished second again. Lola’s Jackie Stewart completed the podium. Mid-Ohio proved the season would not be a procession — but it also confirmed that McLaren needed more than skill to stop Porsche. They needed a miracle.

Round 3 — Road America (July 23, 1972)

Road America was the worst possible battleground for McLaren: four miles of long straights, high-speed sweepers, and terrain that demanded brute horsepower. Porsche expected absolute dominance here, and in qualifying Follmer delivered on those expectations. He claimed pole by an astonishing margin — more than two seconds clear of Hulme. Milt Minter’s Vasek Polak-entered Porsche 917/10 took third, giving the Stuttgart marque its first front-row lockout since joining the series.

The race began with a brutal display of turbo strength. Follmer launched hard, flattened the throttle through the Moraine Sweep, and disappeared into the Wisconsin landscape. Hulme gave chase, but the M20 simply couldn’t accelerate quickly enough to keep the Porsche within reach. Within three laps, the gap had grown to a staggering 15 seconds. The audience gasped as the 917/10 slingshotted out of corners like a jet aircraft taking flight.

Mid-race brought attrition. The high-speed demands punished the field mercilessly: Stewart retired with oil pressure loss, Motschenbacher suffered chassis damage, and Minter’s Porsche began showing signs of overheating. But Follmer remained untouchable. His mastery of the 917/10 at full boost was evident — he modulated the throttle with precise timing, catching the surge without unsettling the car.

Hulme soldiered on in second, knowing that survival was the only realistic goal. He managed a consistent pace but never threatened the Porsche. Behind him, the battle for third intensified between privateer McLaren entries and Minter’s fading 917/10. The power advantage made the difference, and the Vasek Polak car held the podium position.

In the closing laps, Follmer dialed back the boost to protect the engine. Even at reduced power, the Porsche remained unreachable. He crossed the line with the most dominant margin seen since McLaren’s peak years — a symbolic inversion of the papaya supremacy Road America had once displayed.

The message was clear. The turbocharged era had begun, and there was no turning back.

Round 4 — Donnybrooke (August 6, 1972)

Donnybrooke, with its long straights and wide-open terrain, promised another Porsche showcase — but the race became far more chaotic than expected. Qualifying placed Follmer on pole once again, with Hulme second and Minter third. Shadow Racing, with their low-slung DN2, showed surprising pace in the hands of Jackie Oliver and George Follmer’s teammate, but reliability concerns remained heavy.

At the start, the Porsche duo launched perfectly. Follmer took the lead, Minter followed closely, and Hulme settled into third. But early chaos erupted as several midfield cars collided entering Turn 2, scattering debris across the circuit. Hulme narrowly avoided the carnage, but the shuffle allowed Minter to attack Follmer in a rare intra-Porsche challenge.

For several laps, the Vasek Polak Porsche hounded the Penske machine — the closest anyone came to challenging Follmer all season. But as the turbos spooled, as the aero balance shifted with fuel burn, the factory-prepared 917/10 reasserted its superiority. Follmer extended his lead steadily, demonstrating exactly why he had become the championship favorite.

Mid-race brought mechanical attrition. Shadow’s DN2, despite flashes of brilliance, retired with suspension failure. Multiple Lola entries succumbed to overheating. Hulme maintained a lonely third, unable to match Porsche’s raw power but far ahead of the struggling privateers.

Late in the race, Minter encountered fuel pickup issues, dropping him behind Hulme. The McLaren driver seized second — a small but meaningful victory for the papaya camp. Follmer, unchallenged, crossed the line with his fourth consecutive win.

Donnybrooke made one truth unmistakable: Porsche didn’t just have the fastest car. They had two of them.

Round 5 — Elkhart Lake II (August 27, 1972)

(Second Road America round added late-season)

By late August, the series returned to Road America for a second round, increasing the season’s brutality. Follmer arrived undefeated. Hulme arrived determined. And Shadow arrived with significant aerodynamic updates, hoping to close the gap with Porsche.

But qualifying erased any hope of an upset. Follmer claimed pole by nearly two seconds once more. Hulme managed second. Minter locked in third. Revamped or not, Shadow and Lola remained spectators.

The race played out in a depressingly familiar rhythm. Follmer launched into the distance. Hulme tried to cling to the draft but lost the tow after just two laps. Minter played guardian for Porsche, maintaining a steady third.

Midrace drama came not from the leaders but from the midfield chaos — blown engines, fuel fires, brake failures. Donnybrooke had beaten the grid once. Road America was beating it again. The pace demanded by Follmer forced every other car beyond comfortable limits.

In the final laps, the Penske crew instructed Follmer to reduce boost to preserve reliability. Even so, he crossed the line half a minute ahead. Hulme finished second. Minter third. The season standings had become all but symbolic. Porsche held the crown.

And Follmer’s name was now etched into Can-Am mythology.

Round 6 — Laguna Seca (September 10, 1972)

Laguna Seca offered McLaren its most realistic hope of the year, as Porsche’s turbo lag and extreme power delivery could make the 917/10 unruly on short, technical layouts. Qualifying reflected this slight leveling of the field — Follmer took pole, but Hulme trailed by only a few tenths. Shadow qualified better than usual, with Oliver placing fourth.

At the start, Follmer controlled the run into Turn 2, with Hulme staying close. The M20 looked balanced, confident, and quick enough to pressure the Porsche in the corkscrew and the off-camber turns. For the first time since Mid-Ohio, Hulme seemed genuinely capable of challenging for the lead.

But the Porsche’s advantage returned in violent surges. Out of every slow corner, Follmer timed the turbo perfectly, launching down the short straights with a force the McLaren could not contain. Hulme matched him through the high-speed sections and in traffic, but the deficit on corner exit grew into a chasm.

Midrace tension escalated as the Shadow DN2 surged forward in a daring display. Oliver attacked Hulme repeatedly, forcing the McLaren driver into defensive lines. The papaya camp felt cornered: unable to catch Porsche and now under siege from a radical newcomer.

Late in the race, mechanical reliability struck again. The Shadow retired. Hulme regrouped. But Follmer remained untouchable. The Porsche, despite its quirks, had answers for every question Laguna Seca posed.

Follmer crossed the line with his sixth win. Hulme finished second. The season’s arc, now fully visible, was unmistakable.

Round 7 — Edmonton (September 24, 1972)

Edmonton, with its combination of fast sweepers and long straights, tilted the battlefield heavily in Porsche’s favor. Follmer took pole with the largest margin of the season. Hulme lined up second. Minter’s Porsche third. The Shadow cars again qualified well but lacked race reliability.

When the race began, Follmer rocketed away. Hulme held second but lost ground rapidly. The Porsche’s downforce and boost combined to create sector times previously thought impossible. Even with the throttle modulation required to avoid turbo lag, Follmer made the car dance with a mastery that left the crowd in awe.

Midrace, Hulme faced pressure from Minter, whose works-assisted 917/10 ran flawlessly. The two engaged in a fierce duel, showcasing the tactical nuance required to tame such powerful machinery. Hulme defended bravely, but the Porsche’s superior thrust eventually prevailed, and Minter seized second.

Behind them, Stewart battled mechanical gremlins. Shadow suffered another retirement. Privateer McLarens managed steady but unspectacular pace.

In the final laps, Follmer reduced his pace, maintaining control without risking the machinery. He crossed the line with a margin of dominance rarely seen in the series. Minter finished second. Hulme third—his podium streak intact but his hope for a real fight extinguished.

Porsche had fully seized control of the championship.

Round 8 — Riverside (October 1, 1972)

Riverside, the penultimate round, brought brutal desert heat and some of the highest sustained speeds of the season. Porsche expected another walkover. The crowd expected more of the same. But this race would deliver one of the season’s most chaotic and unpredictable battles.

Qualifying told the usual story — Follmer on pole, Hulme second — but the margins were closer. The M20 had been refined continuously throughout the season, and Hulme had found new performance through setup innovations.

At the start, the McLaren surged forward. Hulme led into Turn 6, shocking the field. Follmer followed, biding his time. Minter held third. For the first time since Road Atlanta, Hulme truly led on merit.

The battle raged for half the race. Hulme defended brilliantly, using Riverside’s sweeping lines to neutralize the Porsche’s boost advantage. Follmer remained patient, stalking rather than attacking. The Porsche team knew Riverside’s heat could cook turbos and transmissions alike.

At lap 30, the inevitable attack arrived. Follmer caught Hulme in lapped traffic, timed the boost perfectly, and blasted past on the back straight. The Porsche roared away. The McLaren held second, but the fight was finished.

Late-race attrition filled the leaderboard with retirements — Stewart, Oliver, Minter — all struck by mechanical failures. Hulme preserved second. Follmer claimed another crushing win.

Riverside confirmed it. Nothing could stop the Porsche 917/10.

Round 9 — Laguna Seca II (October 15, 1972)

(Season finale)

The season ended at Laguna Seca, where Follmer arrived already crowned champion. Donohue, partially recovered, assisted the team but did not race. McLaren arrived with resolve and professionalism — ready not to win, but to end with dignity.

Qualifying placed Follmer on pole again. Hulme second. Shadow third. Lola fourth. It was a familiar grid.

When the race began, Follmer made no mistakes. He led through Turn 2 and immediately established control. Hulme gave chase, but the M20 simply lacked the tools to challenge the turbo monster. Shadow briefly threatened before retiring once more. Stewart suffered another mechanical failure.

Midrace, Hulme stabilized in second, aiming to secure the runner-up position in the championship. The rest of the field splintered into small battles — privateer McLarens, aging Lolas, struggling Porsches.

In the final laps, Follmer’s pace softened as he brought the car home safely. Hulme maintained second. And the McLaren team, standing stoically on the pit wall, applauded the driver who had just ended one dynasty and started another.

Follmer crossed the line to complete the most dominant season since McLaren’s prime years — a symbol of the new order.

The 1972 championship belonged not just to Porsche, but to turbocharging itself.

Epilogue — The Porsche Ascendancy

The 1972 season marked the dramatic end of the papaya empire. Six years of McLaren supremacy collapsed under the weight of Porsche’s technological revolution. The 917/10 Turbo was not merely faster — it was from another era. Where McLaren refined, Porsche reinvented. Where McLaren extracted perfection from known principles, Porsche expanded the boundaries of what engines and aerodynamics could be in unrestricted racing.

George Follmer, often overshadowed in earlier seasons, emerged as a deserving champion — quick, fearless, and adaptable enough to tame the most violent machine ever introduced to Group 7. Mark Donohue, though sidelined, shaped the program’s foundation and would soon return to dominate with the even more terrifying 917/30.

Denny Hulme fought with dignity, finishing second in the standings and carrying the final torch for McLaren’s once-unstoppable dynasty. The M20 was a superb machine — but it could not overcome the tidal wave of turbocharged innovation.

1972 was not just a transition. It was a transformation.
Can-Am had evolved from a war of courage into a war of physics.

The age of the turbos had arrived.

Sources:

– Motorsport Magazine Archive — 1972 Can-Am contemporary race reports (Road Atlanta, Mid-Ohio, Road America I & II, Donnybrooke, Laguna Seca I & II, Edmonton, Riverside)
– RacingSportsCars — 1972 Can-Am official results, starting grids, lap charts, and classifications for all rounds
– RacingYears — 1972 Can-Am calendar and final championship points
– Penske Racing Archives — Porsche 917/10 development notes and Donohue testing reports
– Porsche Museum & Archives — 917/10 technical history, turbocharging program documents
– McLaren Heritage Trust — McLaren M20 development, 1972 team structure and season overview
– Shadow Racing historical archives — DN2 technical data, 1972 program summaries
– Lola Cars historical records — T260/T310 development notes and Can-Am results
– Track histories — Road Atlanta, Mid-Ohio, Road America, Donnybrooke, Laguna Seca, Edmonton, Riverside (1972 Can-Am event summaries)