The story behind Mark Donohue’s Winningest Sunoco Camaro Trans-Am Racer
Things are not always as they seem. Take for example, this 1968 Camaro Trans-Am racer. On the surface, it seems to be a stripped-down version of the original-issue production car. Painted Sunoco Blue with all the right lettering, the Camaro was a winner, taking nine of eleven races during the 1968 season with Mark Donohue at the wheel and Roger Penske calling the signals. But this simple Camaro is far more than an initial glance will reveal. A lot more.
TRANS AM SETS THE STAGE
The Sports Car Club of America created the Trans-American Sedan Championship in 1966. For a car model to be qualified for competition, no less than 1,000 examples had to have been produced during the prior 12 months. The rules were based on those of FIA Groups 1 and 2, although in the Trans-Am they were referred to as A/Sedan and B/Sedan. Classes were then broken up based on engine size: 0 to 2,000 cc, and 2,001 to 5,000 cc (this later became 0 to 2,500 cc and 2,501 to 5,000 cc). The maximum wheelbase was 116 inches. Eventually, an 8-inch wheel width limit would be introduced for the Over 2 Liter class cars, as well as a minimum racing weight of 2,800 pounds (1,270 kilograms).
Penske and Donohue first met in 1959, but it wasn’t until 1966 that the pair finally teamed up for the first time. Donohue was a mechanical engineer, studying at Brown University in Providence, Rhode Island. For 1966 he picked up a factory ride in endurance sports car racing with Ford’s GT MkII program, running at selected events including Daytona, Sebring, and Le Mans.
Donohue and Penske’s connection occurred that April, when Penske asked Donohue if he’d like to drive his Lola T70 Spyder in USRRC and Can-Am events, to which Donohue agreed. Penske paid him the lofty sum of $50 per day for each day he worked. For context, Donohue held down a full-time 9-to-5 day job at the same time, with racing still very much a weekend hobby for him, despite the intensity with which he attacked it.
After a challenging 1967 season where the Penske/Donohue Camaro finished second in the driver’s championship to Jerry Titus thanks to Donohue’s season-concluding race victories in Las Vegas and Kent, Washington, Team Penske was more dedicated than ever to taking the 1968 Trans-Am title. For 1968, two all-new Camaros were built using all the knowledge and experience gained during 1967. A beefy rollcage connected all four corners of the car greatly improving handling through heightened chassis stiffness.
Under the hood was a 302-cu.in. V-8 engine built by noted race engine specialist TRACO (a play on the owner’s surnames, engine builders Jim TRAvers and Mike COon). The engine was extremely efficient, generating around 450 to 475 horsepower, and backed by a four-speed Muncie M22 transmission along with a GM 12-bolt rear end containing a limited-slip differential. Koni shocks were used at all four corners. Brakes were 11.75-inch Corvette discs, and 15 x 8-inch magnesium American Racing wheels were wrapped with Goodyear tires after Penske switched away from Firestones. Bumpers were removed, as allowed under the rules, while the fenders were flared very lightly to house the wheels and fat racing tires.
WHAT YOU DON’T SEE
Penske, just like all the factory teams, tended to walk a tightrope when interpreting the rules. In most cases, if the rulebook didn’t specifically state something was illegal, the assumption was that it must then be legal. In cases where rules were specific, the factory teams would go to such lengths as carefully manipulating factory parts to look stock while yielding improved performance. The Penske crew built clever “interpretations” into the ’68 cars, such as moving back the control-arm mounting position and shock towers so that during SCCA tech review, they still measured as factory stock. Illegal Heim joints were hidden inside the control arms so quick suspension adjustments could be made.
In 1968, most American cars featured a flat front end design, which cut through the air like a brick. It became clear that if Team Penske could “massage” the front sheetmetal, there could be a huge aerodynamic benefit. While taking care to retain the original factory look of the car as required by the rulebook, Penske engineer Rob Fournier sliced at least an inch out of the radiator core support height. By doing so, he brought down the front sheetmetal, bringing the nose closer to the ground and creating less frontal area, aiding straight-line speed.
As the laws of physics dictate, every action has an equal and opposite reaction. With the Camaro nose section now lower to the ground, the fenders were pushed further forward and left a sizable gap between the top edge at the rear of the fender and where it met the body cowl. In addition, the lower rear edge of the fender overlapped with the front of the door. To adjust for this, the fenders had to be trimmed and/or extended and modified to create an acceptable door seam and achieve a factory stock appearance. Along with these metal modifications, it turned out that after acid dipping, the race weight of the 1968 Penske Camaros was almost the exact minimum allowed at the Trans-Am race limit of 2,800 pounds. Curb weight for a production 1968 Z/28 Camaro was 3,060 pounds.
Mark Donohue: March 18, 1937 – August 9, 1975. Raising his first trophy at War Bonnet Raceway Park in May of 1968. A tire failure while practicing for the Austrian Grand Prix led to his untimely death at 38. Image courtesy of Tom McIntyre
For 1968, the Trans-Am season would start with the Daytona 24-Hour race, rather than a season startup a couple of months later. Penske entered just one car (not the car that would start the season at War Bonnet), to be driven by Donohue, Craig Fisher, and Bob Johnson. They qualified 20th overall, and fastest of the Trans-Am cars — two places ahead of the first Shelby Mustang. The Penske Camaro was marginally faster on track, but the Shelby teams were quicker in the pits — specifically with brake-pad changes.
With a second-place finish at the hands of the Shelby team during pit stops at Daytona, Chevrolet’s Bill Howell devised an intriguing system for speeding up brake-pad changes. Donohue explained in the book he co-authored with Paul Van Valkenburgh, The Unfair Advantage: “The problem (when performing a normal pad change) was that when we slipped the old pads out, the (internal caliper) pistons slid out, preventing the new pads from going in easily. The Ford guys had developed some special tools that pushed the pistons back into the caliper, but that took some time also. Bill’s idea was to put a vacuum on the master cylinder to pull the pistons back in. We already had a source, in the brake booster vacuum, so all we needed was a pressure regulator to prevent sucking air in past the pistons and a valve so that the driver could actuate the system.”
The Donohue/Fisher Penske Camaro was the top qualifying Trans-Am car at the second competition—the 12 Hours of Sebring. While there was little to separate the Chevys and Fords on the track, each time they performed a brake-pad changes using their new system, the Penske cars would gain a lap on the Fords. After 12 hours, they were four laps ahead of the fastest Mustang. The Penske team were standout performers at Sebring, finishing an astounding third and fourth overall behind two factory Porsche 907 sports prototype cars, showcasing just how professional the Trans-Am teams had become.
DOMINATING RACE CAR
Close examination of the control arm and subframe identify tasks associated with rule interpretation.
The debut of all-new 1968 Trans-Am Camaro (the one shown here and owned by Tom McIntyre) occurred at the third round of the 1968 Trans-Am series, which was held at War Bonnet Park near Mannford, Oklahoma. Donohue took pole position and won comfortably. His closest rival at the end was George Follmer in one of the new Ron Kaplan-prepared AMC Javelins. At the fourth race in the series at Lime Rock, Connecticut, Donohue again started on the pole, and won handily, taking victory over Jerry Titus by two laps. At Mid-Ohio, the Penske team set themselves a new challenge, missing qualifying while Donohue was away at Mosport Park racing an Indy car. Due to his absence, he started the race at the back of the grid but moved into the lead by lap 10 and was a lap ahead of Jerry Titus by the finish.
For Bridgehampton, the Sunoco Camaro program expanded to two cars, with Sam Posey putting together a deal with Roger Penske to drive the car raced earlier in the year at Daytona and Sebring. Posey finished the race in third place, behind George Follmer’s Javelin, and race/pole winner Donohue. At Meadowdale, the results were the same, only it was Peter Revson’s Javelin that split the Sunoco Camaros. Donohue then beat Follmer and Posey at St. Jovite—a full lap ahead of second place once again. With few exceptions, the rest of the season was much of the same.
In the end, the Sunoco 1968 Z/28 Camaro dominated the competition, winning nine out of eleven races, as noted earlier. They did so against full, factory-backed teams of Ford Mustangs and AMC Javelins, as well as several heavily funded independent operations including that of Canadian Terry Godsall, which, with Jerry Titus on board, would go on to run the factory Pontiac program in 1969.
As has been said repeatedly, manufacturers don’t go racing just to help pad out the grid. Racing is marketing; “Win on Sunday, sell on Monday.” But there is no catchy adage for the car that finishes second on Sunday. To finish second suggests the product is second best. Sales of Fords Mustang dropped from 472,000 in 1967 to 317,000 in 1968. Meanwhile, Camaro sales grew from 221,000 in 1967 to 235,000 in 1968. A good portion of that customer loyalty and growth could be attributed to the familiar sight of Mark Donohue and his cool blue Z/28 with the yellow Sunoco Camaro lettering.
CHAMPION GONE TO STUD
Image courtesy of Tom McIntyre
The Penske/Donohue/Sunoco Z/28 Camaro’s domination in 1968 pushed their team’s rivals to press harder in 1969, and each of the factory-backed teams built completely new race cars. That included Roger Penske, who stepped up to run a full-time, two-car operation. Two new ’69 Camaros were constructed, one for Donohue and a the second for the new Team Penske driver, Ronnie Bucknum. As part of his arrangement with Roger Penske for 1968, former team driver Sam Posey paid for and took possession of a championship-winning ’68 Camaro. Curiously, it appears Posey ended up with the car driven by Donohue rather than the car he drove in 1967. In early 1969, Posey decided to sell the Camaro for $12,000, but did not find a buyer.
While Donohue’s ’68 Camaro was gathering dust at Sam Posey’s (Posey himself had a one-off drive for Shelby in 1969 and won), Penske bought the car back after watching a pair of Bud Moore 1969 Mustangs almost take each other out at a race early in the season. Penske quickly upgraded the car to 1969 specs, installing a new engine, new paint, front and rear bumpers (new Trans-Am rules for 1969 required bumpers) and replaced the American Racing wheels with yellow-painted Minilite wheels to match the ones being used on the ’69 cars. Penske tucked that “hero” Camaro into his semi and hauled it around for the 1969 season simply as a backup. Fortunately for Penske, its services weren’t needed and at the conclusion of the 1969 season, the three team cars were off-loaded to new owners since Penske had signed a lucrative deal to run the factory Javelins for American Motors. Bye-bye, Camaros!
The Sunoco 1968 Z/28 Camaro was purchased from Penske by Craig Murray, president of the recently opened (1968) Sears Point Raceway (now called Sonoma Raceway). Murray had picked up his competition license in early 1969 but little was changed other than the numbers on the car and adding a passenger door-mounted rearview mirror. Throughout the 1970s, the Camaro changed hands several times, moving to John Elder in Minnesota, before it was purchased by Bruce Belcher in Idaho, and then Bill Freeman in California (at the time of purchase, Freeman was in the process of teaming up with Paul Newman, establishing Newman-Freeman Racing). Freeman’s purchase of a Porsche 911 RSR meant new ownership for the Camaro, the car heading to Bob Eckhardt (also in California), who raced it twice in IMSA events at Ontario and Riverside.
An enormous quick fuel cap certainly sped up the stops, but potential disaster was always a risk.
Amazingly, throughout this era of massive change in sedan racing, the Camaro stayed the same. While many other former Trans-Am cars underwent heavy modifications to keep pace with newer, more purposeful technology, larger engines and wheels and modified bodywork, the old Penske Camaro somehow survived it all unscathed, virtually intact and unchanged. Eckhardt finally sold the car to Tom McIntyre in the early 1980s. Until 1992, this Camaro remained the winningest single chassis of all time, proving Penske’s amazing ingenuity and execution. Some 57 years later, Penske continues to find ways to take his teams to the winner’s circle regardless of the type of racing involved.
McIntyre spent many years restoring the Camaro back to its 1968 condition, finally returning it to the track once more in 1993. McIntyre has been integral to the growth of the Historic Trans-Am group, the most popular group in Vintage Racing for cars that raced in the original Trans-Am series from 1966 through 1972. Interest in the group is huge, with new Trans-Am cars from the past being discovered, restored to original condition, and taking to the track.
The Penske/Donohue 1968 Trans-Am Camaro team made an indelible mark on the Trans Am racing world with their ingenious engineering, breakthrough designs, and innovative ways to solving race challenges that still resonate today. But their biggest “secret” was the innate talents of Mark Donohue himself. Arguably, no one has ever come close to blending his talent for engineering with driving skill. The Penske/Donohue racing team was an amazing partnership that ended far too soon.
Thanks to Tom McIntyre and Jon Mello for their help with this article.
