The Zeitgeist of Domination: Mark Donohue and the Porsche 917/30

Historic and on-track photos courtesy Porsche. Lead photo courtesy Canepa. Body-off photos by Tim Suddard.

The no-holds-barred Can-Am series featured some of the world’s most technologically-advanced creations driven by the day’s top drivers. And then in 1973, Mark Donohue—backed by Roger Penske’s juggernaut—silenced everyone with their 1500-plus-horsepower 917/30.

Suddenly, “unlimited” had become perhaps too unlimited.

So dominating was Porsche’s 917/30 that McLaren, the only other manufacturer to even challenge Porsche at that point in time, pulled out before the 1973 season even began.

It wasn’t because Porsche had a better chassis that it was leaving the series. Or a better engine,” George Levy writes in Can-Am: 50th Anniversary. “It was because Porsche had a better transaxle.”

McLaren’s big-block Chevrolets could generate more than a thousand horsepower, the book continues. The team’s Hewland gearboxes, however, just couldn’t take it.

Again, Porsche’s effort was so dominating that—after finishing seventh and second, respectively, in the 1973 season’s first two contests—Donohue would rebound to win the final six on the schedule, capturing 139 points. George Follmer, the previous year’s Can-Am champ, finished second in the standings with only 62 points to his credit. Hurley Haywood would wind up third with 47 points.

How dominant was that Penske effort? From John S. Radosta’s New York Times’ report of the Watkins Glen contest, the third one on the schedule and the first that Donohue wound win: “Donohue started from the pole, led for every one of the 202 miles and coasted during the last third of the race. He finished with a comfortable margin of 42.87 seconds over David Hobbs, whose Carling McLaren‐Chevrolet survived a cracked engine block. The leak was plugged with radiator compound and an epoxy patch.”

During that showing, the Times article continues, Donohue recorded a trap speed of 196.7 mph.

Some more tidbits from that report: “The weather was sunny and warm, with a crowd of about 60,000, most of them young campers in varying degrees of undress.” A nice way to witness racing domination.

Porsche created the 917/30 specifically for that 1973 Can-Am season. It was an update to the 917/10, the car that Penske and others campaigned the year before. It would remain the weapon of choice for those battling for second place in 1973. (Donohue was injured while testing for the 1972 season, hence Follmer’s place in a Penske Porsche that year.)

Where the 917/10 saw action around the globe, the 917/30 had just that single mission: fulfill Donohue’s wishes in order to dominate Can-Am.

To that end, the new car was longer than its predecessor, already a top machine. The 917/30 featured better brakes—a Donohue request—plus improved aero courtesy of SERA-CD, a French firm that specialized in such matters.

The new Porsche also carried more fuel. Where the 917/10 had room for 86 gallons, the 917/30’s five tanks–four placed between the wheels and the fifth behind the driver–expanded capacity to 106 gallons.

Boost was adjustable by the driver, a new concept at the time.

Then there was the engine, a 5.4-liter flat-12 fed by two turbos. Some figures according to the placard displayed alongside the car at this summer’s Porsche Rennsport Reunion:

Horsepower: 1250-1560 (depending on boost)

Top speed: 240+ mph

Weight: 2000 pounds

Zero to 100 mph: less than 3 seconds

Zero to 200 mph: 10.7 seconds

To complete the package there was the immaculate presentation, a Penske hallmark. “It was an integral part of the Penske psychology to convince other teams that their cars had been so well-prepared for racing so far in advance that the crew had nothing left to do but paint, trim and polish,” Karl Ludvigsen wrote in Porsche: Excellence Was Expected.

Porsche only built six copies of the 917/30 chassis. The first was the development car. Donohue started the 1973 season in the second one but, after a pre-race incident, Penske pressed the third car into service. That third car, 917/30-003, is the one that Donohue drove to wins at Mid-Ohio, Road America, Edmonton, Laguna Seca and Riverside. (The other 917/30 chassis weren’t raced during the 1973 season.)

Those two cars driven by Donohue during 1973 are still out there. Porsche owns chassis number 2.

And while visiting Canepa, one of the world’s 917 specialists, we spied 917/30-003 in the middle of a service: body removed so all of the inner goods could be seen. 

Just how dominating was that 917/30? By all accounts, the final event of 1973 was boring. Donohue grabbed the pole over Follmer by 1.3 seconds.

And once the green waved, Donohue just cruised to an easy win, playing with his newly installed adjustable rear anti-roll bar. Just Hurley Haywood finished on the same lap. Not only was the rest of the field well off the pace, but most failed to finish due to crashes or mechanical issues; only eight of 21 entrants took the checker.

Donohue announced his retirement soon after.

For 1974, the SCCA added a big restriction to the once-unlimited Can-Am rules: In an effort to acknowledge the OPEC oil crisis, cars would have to meet a fuel economy standard. “But the Panzer people saw nothing in any of this for them,” Pete Lyons writes in Can-Am, his tome on the series. “Porsche let Penske out of the third year of his original contract.”

1974 would be interim year, the SCCA explained, with a new formula for 3.0- and 5.0-liter cars coming for the following season.

Before that 1975 season, though, the SCCA made another announcement: Can-Am was dead. The name would come back for 1977, but those were basically Formula 5000 cars wearing bodywork.

The original—the unlimited Can-Am series—had come to end, with Donohue’s 917/30 being the series’ exclamation point.


Donohue didn’t participate in the 1974 Can-Am season, but his car did. Brian Redman drove it to a second-place finish at Mid-Ohio.

Even though Donohue had announced his retirement at the end of the 1973 season, he got back into the cockpit in order to drive for Penske’s 1975 Formula 1 effort. Donohue and 917/30-003 paired up once more as well, setting a closed-course record at Talladega Superspeedway: 221.160 on August 9, 1975.

And 10 days later, Donohue was dead. On August 9, while practicing for the Austrian Grand Prix, a tire failure sent his March 751 off-course. A corner worker was killed by the debris. Donohue initially seemed okay but died the following day due to a cerebral hemorrhage.

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wspohn Dork
4/12/19 4:39 p.m.

The 917 was one awe inspiring car.  Porsche was struggling economically in those days and that car saved them. I saw them up close in 1982 when they came to the Monterey Historics and I was also racing so got to talk to the drivers and mechanics, and believe me, the cars were impressive indeed.

The recent Grand Tour episode pitting a 917 against a modern 911 GT2 RS merits rewatching!

Gary SuperDork
4/12/19 7:27 p.m.

The 917 was a great race car to begin with, but it's a testament to Mark Donohue, race car engineer extroadinairre, to adapt it to a "private" team for the US CanAm series and to dominate so well.

You may have the best and brightest design engineers who come up with a fantastic new ground-breaking product. But it needs to be developed. The development engineers are heros too, and deserve just as much of the credit as the conceptual design engineers.

Aktifspeed New Reader
4/12/19 7:58 p.m.

In reply to Gary :

Gary,  “The Mudge Pond Express” is an autobiography of Sam Posey’s racing career  


4/13/19 12:21 a.m.

In reply to Gary :

I saw Mark Donohue race the 917/30 at Laguna Seca in 1973. The car was stunning but the best part about the car was the sound . You could hear it way down the track above any other car. I have a picture of Donohue in the car just prior to leaving the pit area. It was a lucky time to see him.  I also had the chance to see the preparation before the race. The crew winch a spare engine out of the back of a semi truck. I seem to remember it was painted a green sort of a military color. The whole engine was absolutely business 

4/13/19 6:25 a.m.

In reply to Gary :

I think his only point is “The Mudge Pond Express” is Sam Posey’s autobiography. Mark Donohue wrote “The Unfair Advantage”. Both good reads and big dollars these days on the used book market. Cheers. 

Frank Calandra
Frank Calandra New Reader
1/2/21 2:39 p.m.

I saw the debut of this car at Mosport Can-Am in Canada. First impression was it was far quieter than the rest of the field. Second was it was a lot faster. Donahue had to pit with throttle linkage issues and lost some laps. When he went back out, he proceeded to reel them all in, and was in 2nd when the checkers waved. One more lap and he would have won. That performance pretty much spelled the end for Can Am. The other teams didn't have the resources Penske and Porsche had and moved on to other classes after 1974. 

chandler UltimaDork
1/4/21 6:24 a.m.


5/26/22 12:46 p.m.

I also saw the 917/30 one year at the Monterey Historics when Porsche was the honored mark. I believe George Follmer was driving it on some demonstration laps. What I noticed immediately, besides how beautiful it was, was how quiet it was due to the twin turbos. The tires screeching around the corners was almost louder than the car. Also had a chance to talk to Sam Posey who was there interviewing different drivers. Very approachable and nice guy. 

GeoWeb New Reader
9/19/22 10:04 a.m.

In reply to Frank Calandra :

It was a long time ago but my recollection of the 930's debut at Mosport is slightly different from Frank Calandra's -- perhaps I remember different details. Donohue had put the Porsche on pole easily. when the race started he immediately pulled away from the rest of the field. Only a few laps into the race (I used to think it was on the first lap but that would have had to have been impossible) he crested the hump on the back straight and immediately caught sight of the slowest Can-Am car in the field too close to avoid. Caught by surprise, the Porsche slammed into the back of the other car and it spun off the track. He pulled into the pits for repairs (there was visible damage to the front of the Porsche) and continued, having lost time. As Frank notes, after that the tremendous speed of the car compared to the other 'unlimited' Can-Am cars was such that he nearly made it back into the lead by the time the checker fell. Regardless of the details, Frank and I saw the collapse of the original Can-Am concept thanks to Roger Penske and that remarkable car. I think there are still race fans who hold Penske responsible -- but how can you blame him for reading the rule book and arriving with a  overwhelming car? We saw that again when he came to Indianapolis with the pushrod Ilmor (Mercedes) engine and dominated that race.


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