General Motors is planning a three-pronged attack for Le Mans

Cadillac’s first showing at the 24 Hours of Le Mans had nothing to do with General Motors. In 1950, the wealthy sportsman Briggs Cunningham entered two Cadillacs, a bone-stock Series 61 sedan and a second Series 61 with a freakishly pancaked body, which the locals nicknamed “Le Monstre.” The stock sedan finished 10th overall, with Le Monstre one lap behind in 11th. The 50 cars that finished in Cunningham’s wake included a Jaguar XK 120, a Ferrari 195 S driven by Luigi Chinetti, and an Aston Martin DB2.

Since then, other than a brief Cadillac effort in the early 2000s, Chevy has carried GM’s Le Mans torch, racking up eight class wins with Corvettes. This June, however, the General heads to France with an expanded stable of cars that will compete in three classes, including a new hybrid-powered Caddy GTP car that finished third in the 24 Hours of Daytona and has the speed the win the whole thing. “We are bringing the red, white, and blue, with a very powerful punch,” said GM’s sports car racing program manager, Laura Klauser.

In addition to the Corvettes and the Cadillac GTP, GM is also sending a NASCAR Camaro to be run by Hendrick Motorsports. Unlike in 1950, General Motors is directly involved in the effort this year. All the cars use V-8s built in GM’s Pontiac, Michigan, facility, for starters. We’re acknowledging this historic American effort by explaining GM’s Le Mans machines below. The green flag waves on June 10 at 9 a.m. ET.

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The 200-mph hybrid-powered Cadillac

New-for-2023 sports-car racing rules created a GTP class that is eligible for all the major endurance races, including the 24 Hours of Le Mans. This type of race car is known as a “prototype,” and while the GTP car looks similar to previous prototype racers, it’s a much different machine under the skin. Here are some highlights.

01. Bodywork

A major rule change for 2023 allowed GTP competitors to design significant brand identity into the cars. This Cadillac GTP may not be available in showrooms, but you can probably tell it’s a Cadillac from its body, which is made from lightweight, high-strength carbon fiber. This branding integration is one reason why Porsche, BMW, Acura, and soon Lamborghini are fielding factory GTP cars.

02. Powertrain

GTP cars are limited by the amount of total horsepower—670—that they are permitted to deliver to the tires, and they must include an electric boost motor. This rule has encouraged a variety of engine types, such as the small-displacement V-6 turbo used in the Acura ARX-06, and the Cadillac V-8. GM’s engine is like the one in the new Corvette Z06 in that it uses overhead cams instead of pushrods to operate the valves, but it has a different crankshaft from the Corvette that sacrifices peak power for less vibration. A seven-speed transmission routes torque to the rear wheels, and the electric motor is powerful enough that the cars leave the pits on battery juice alone.

03. Torque Sensor

This small collar is made by MagCanica and is a torque sensor that sends information in real time to the race officials, who ensure that the cars are never putting more than 670 horsepower to the tires. The greatest challenge for teams is how to blend the electric and gas motors and when to deploy electric boost. “That’s why we have 80 spreadsheets,” quipped GM propulsion engineer Adam Trojanek.

04. Brakes

The GTP car charges the battery while under braking. The more braking energy the system can harvest, the greater the fuel saved and, potentially, the less time the car will spend refueling in the pits. The rear-axle brakes are computer-controlled and blend resistance from the electric motor with braking force from conventional brake calipers. This stopping power is integrated with the front brakes, which are hydraulically connected to the brake pedal. One of the many challenges here is linking the various systems and maintaining consistent brake-pedal feel so the drivers have the confidence to go faster and brake as late as possible.

Camaro joins Corvette

Corvette has been a consistent winner at Le Mans for the past two decades, racing against the likes of Porsche, Ferrari, and Aston Martin. This year, Camaro joins Corvette in the Chevy pits for even more American V-8 rumble on the Mulsanne straight.

Corvette Z06 C8

You don’t need to see the Corvette or the Cadillac to know which one is going by. The Cadillac has a traditional, deep V-8 rumble, while the Vette is a howler, coming closer to a Ferrari’s sound than a big-block’s. There is only one C8 running Le Mans this year, and it will have to atone for Corvette Racing’s disappointing 2022 effort, in which the two factory Vettes failed to finish. Chevy just announced that it will sell customer race versions of the C8; a GT3 version will cost nearly $1 million. This could mean several more Corvettes racing by private owners in 2024, who are likely waiting to see how the car performs this year. Corvette Racing, which is based near GM’s proving grounds in Milford, Michigan, knows how to win.

Chevy Camaro Garage 56

In 2012, Le Mans organizers introduced Garage 56, a special class for an experimental or unclassified car. This year, that entry will be taken by a modified Chevy Camaro NASCAR stock car. Since the car is in a class of one, this is largely a publicity stunt meant to showcase NASCAR. GM and Hendrick Motorsports have modified the car with new aerodynamics and other tweaks for greater speed. They’ve also hired premier drivers. Seven-time NASCAR Cup Series champion Jimmie Johnson will split driving duties with Formula 1 champion Jenson Button and Mike Rockenfeller, who co-drove a diesel Audi R15 to an overall Le Mans win in 2010.

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This article first appeared in Hagerty Drivers Club magazine. Click here to subscribe and join the club.

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