How Mercedes-Benz skirted a racing ban with AMG’s Red Pig

Walking up to the Red Pig (a.k.a. die Röte Sau), you’d never guess it’s actually a replica of AMG’s first-ever race car, a 300SEL 6.3 that won its class and came second overall in the 1971 Spa Francorchamps 24 hours. How that original car came to be is almost as unbelievable. 

Underneath the period stickers for Camel cigarettes and Levi Jeans, this car is redder than a fire engine. The surprisingly lithe shape, fashioned in thick Stuttgart steel, has been raceified with cartoonish extended wheel arches over massive tires. The conversion is both shocking and thrilling, ’70s Modsports engineering versus Paul Braque’s elegant design for the Mercedes-Benz W108/109 S-class.

Climb in through the roll cage, settle in the unnerving bucket seat, and fasten four-point Willans belts. The dash is pretty standard ’60s S-class, with classy light-wood veneer and a twin-dial binnacle. A watch-sized rev counter sit in between the stock instrument cluster, complemented by a square clock as big as, um, a packet of Camels. Start it up it and the muffled growl of a big bore V-8 sounds like a box of bears. And the replica isn’t even as monstrous as the original.

“It was an amazing car—enormous with huge speed,” says Hans Heyer, who drove the Red Pig, along with Clemens Schickentanz. “We had enormous speed comparing to the Capris, but no brakes at all…” 

Following the race at Spa, the original Red Pig went around Europe doing demonstrations before being sold to Matra to test jet fighter tires. With its 420-bhp, 6.8-litre V-8 it was the only car big enough, heavy enough, and fast enough to push a tire into the ground at the landing speed of an aircraft. And despite its phenomenal race record, the car was nowhere to be found when Mercedes-Benz wanted to celebrate buying AMG in 2005 and turning the tuner shop into the company’s official performance brand. After searching northern France for the car, Mercedes decided to build its own. Demand to see this extraordinary race replica is so high that Mercedes-AMG built a second Red Pig for static display.

Both Red Pigs have been busy this year, partly to celebrate the AMG’s 50th anniversary. The ace tuning and racing firm gets it name from founders and former Mercedes-Benz race engineers, Hans-Werner Aufrecht and Erhard Melcher plus Großaspach, Aufrecht’s hometown. 

But while the original Red Pig campaigned under the colours of AMG, which at the time was completely independent, the car in fact was more like a skunk works Mercedes-Benz race project, partly funded and mainly engineered out of the Mercedes plant at Untertürkheim near Stuttgart.

Years earlier, Mercedes-Benz withdrew from all forms of motorsport (until the late 1980s) after the tragic 1955 accident at Le Mans, in which Pierre Levegh’s Mercedes flew into the grandstands, killing the driver and 84 spectators and injuring at least 180 more. The incident shocked the racing world and, of course, Mercedes-Benz.  The ensuing ban helped create AMG out of the weekends-and-evenings business Aufrecht and Melcher set up to cater to a growing audience of racers and tuners. 

Mercedes engineer Erich Waxenberger, who with the tacit support of a few senior Mercedes managers and board members, shoehorned the monster M100 V-8 from the 600 Grosser limousine into the W108/109 bodyshell, which up to that point was only available with inline-six engines. Rumour has it that when his boss, Mercedes’ motorsport/development engineer Rudi Uhlenhaut, took a test drive he stopped at the first red traffic light and opened the hood to see how that huge engine had been crammed in there.

Mercedes-Benz’s version of the muscle car was an outstanding vehicle and also one of the first “sleeper” or “Q” cars, where unassuming looks hide serious performance. First shown in 1967 and launched in ’68, its hand-built 250-hp/369 lb.-ft. (DIN) single-overhead camshaft  V-8 used Bosch mechanical fuel injection with a four-speed automatic transmission and air suspension. At 3,889 pounds, it was heavy. And for $14,000 in 1968 (equal to about $100,000 in today’s economy), it was also extremely expensive. This was, nevertheless, the world’s fastest four-door sedan—top speed was quoted at 142 mph. In four years of production, 6,526 were built.

Waxenberger was restless to go racing, and using a diverted PR fund, bored out the engine to a mighty 6.8 liters and put the 300SEL on a diet. He reportedly build three race cars (though some claim there were five) and took them to Macau in 1969. Waxenberger himself took the wheel of the only right-hand-drive version, and while tire wear and thirst were problems (apparently the cars had a race gas mileage of 5 mpg), he won the six-hour race outright. That car is reputed to have remained in Asia. There’s also one in the Mobilia automotive museum near Kisaranta in Finland. 

Following extensive European tests and data gathering, Waxenberger’s patrons tacitly approved an entry to the 1969 Spa Francorchamps 24 hours, but it was apparent that without extended wheel arches covering larger wheels, the tires would chunk and potentially delaminate. Waxenberger’s supporters, realizing this secret program was starting to run horrendous risks, ordered that the Spa entry be withdrawn and the racers quietly sold, with two going to AMG.

So AMG bought two race cars and the unofficial services of Waxenberger, still on the payroll of Mercedes, who brought engineering data, comparative lap times, and engineering know-how. Waxenberger’s driving skills were also put to the test when he just happened to be in the vicinity of AMG’s test race at the Salzburg Ring when the scheduled driver went sick, conveniently with his helmet and overalls at the ready. By this time the cars weighed around 3,527 pounds and were capable of 165 mph. They could do 0-62 mph in 4.2 sec.
At Spa it was on a special air suspension system made for the car by Waxenberger,” Heyer recalls. “And the other thing that was a bit special was the automatic gearbox, the first I’d come across as a driver. Waxenberger modified it so you could change the gears like a sequential gearbox.”

By all accounts it worked pretty well, but it took a special knack to get started after a pit stop. “In general, it was a great car,” Heyer says, “but after Spa, it was fitted with a normal ZF five-speed manual.”
Fast forward to 2005 and, with a Geneva auto show deadline fast approaching, Mercedes installed a standard 6.3-litre engine and an automatic gearbox to its replica Red Pig. For this anniversary year that was replaced that with a five-speed manual, which Waxenberger actually homologated for the road car back in the day. 

“The replica is a street car, and far away from the 1971 car,” Heyer says. “But each year they rebuild it a bit closer to the heart of the original.”

We had the opportunity to drive the replica at England’s Silverstone Circuit. As the air suspension builds pressure, the car lifts its three-pointed star hood ornament like a gun-sight, ready to snipe the apexes of the Formula One track. The Red Pig rumbles along nicely. It feels fast, but not scarily so. The engine’s massive torque makes it hugely flexible, which helps because the rev counter is almost invisible. There’s a redline marked at 5,500 rpm, but you hardly need to extend the engine that far, or even change gears. Just push the throttle and climb onto a thundering wave of thrust. 

The steering is light but accurate, and placing the car’s nose through the turns is a deliberate process in which you ease it into the corner and try to maintain grip through the corner. The ride feels beefed up compared to the floaty standard of an old road car, but center of gravity is high and the body leans through the faster corners is like a ship in a gale. That said, there’s far more grip than you’d expect, thanks to lots of negative camber and those humongous tires. Gently hint at the controls and the old sow goes pretty well. Well, up to a point.

So while it’s easy to assume that 46 years ago Heyer and Schickentanz were having an easy, unstressed time of it, wafting round the circuit, enjoying the ride and waving at the girls, the truth is somewhat different, as Heyer explains.

“It was so fast and it handled pretty great. All the fast corners except Eau Rouge were flat, which was simply not possible with other cars of the time, and uphill it was amazing. To get it round that fast though, you needed a lot of courage, more than you normally needed at the time. But it was fun and manageable, and it would drift with all four wheels.”

There’s a bit of YouTube footage of the original ’71 race, where contemporary fashions, hair styles, pre-aero softer style of racing, and the fantastic look and sound of a bygone era raises a nostalgic smile. Heyer says the 24 hours attracted a big and knowledgeable crowd that was respectful of the speeds and risks. “Everybody was fascinated with our big car.”

He reckons without the big Merc’s frequent fuel stops, he and Schickentanz could have won overall. They ended three laps behind the factory Ford Capri RS2600 driven by Dieter Glemser and Alex Soler-Roig, but everyone remembers the Big Red Pig.

A few laps in this street replica hardly touches Heyer and Schieckentanz’s hard and skilled drive, but it does make you respect their efforts all the more. Especially when you consider that AMG’s first race car was a semi-factory effort from a time when Mercedes wasn’t supposed to be racing at all.