How NASCAR is aiming to thrill on its Le Mans return

“It’s going to put a smile on people’s faces.”

That’s how Jenson Button sums up the machine in which he is making his second Le Mans 24 Hours start. It’s something out of the ordinary, a car that tips its hat to the past and perhaps also the future. It’s a NASCAR Cup racer to all intents and purposes and it fills the Garage 56 slot reserved on the grid for an experimental racer, the so-called Innovative Car.

The truth is that the Hendrick Motorsports Chevrolet Camaro ZL1 isn’t really very innovative, nor is the idea of bringing a NASCAR to Le Mans new. But the history of the US stock car series at the French enduro underpins the thinking behind this year’s campaign with an all-star line-up comprising Formula 1 world champion Button, seven-time NASCAR Cup Series champion Jimmie Johnson and 2010 Le Mans winner Mike Rockenfeller.

Nearly half a century ago, in 1976, NASCAR founder Bill France hatched a plan for a pair of cars from what was then known as the Winston Cup to race at Le Mans to showcase his series in Europe during the US’s bicentennial year. Hershel McGriff and Wesley ‘Junie’ Donlavey respectively entered a Dodge Charger and Ford Torino together with NASCAR – the name of the sanctioning body was on the entry list.

Jim France, president and CEO of both NASCAR and sportscar sanctioning body IMSA today, remembers well the quirky programme set in motion by his late father and decided to recreate the magic that surrounded the arrival of two thundering stock cars in France all those years ago. And more to the point, to do it in a year of another two important anniversaries – the 100th for the 24 Hours at Le Mans and the 75th for NASCAR – and at a time when links between IMSA and Le Mans organiser the Automobile Club de l’Ouest are growing ever closer.  

“It’s been almost 50 years since my father took NASCAR over to Le Mans,” says France. “I remember asking Dick Brooks, one of the drivers [in the Donlavey Ford], what his thoughts were on it. He said, ‘Number one, the fans loved the car, number two, it was a fantastic experience and number three, it was a hell of a challenge.’ I know all the folks involved in this project like a challenge.”

NASCAR president Steve Phelps reckons the programme is a good way to spread the NASCAR message to a wider audience early in the second season of its new Next Gen Cup racer: “We as a sport are trying to look at things that are different, and that put us apart. That is exactly what this opportunity is. We have a series in Europe – the NASCAR Whelen Euro Series – and we know there is enthusiasm for NASCAR in Europe, but this is going to take it to a new level.”

Heavy metal NASCAR machinery taking on Le Mans is nothing new - this Ford Torino lasted for 11 hours in 1976 - and now a stock car is back

Photo by: Motorsport Images

Rick Hendrick, boss of an eponymous team with a record 14 titles in NASCAR’s premier series to its name, and Chevrolet jumped at the chance to be involved. Hendrick describes it as “an honour to be asked”, while Mark Stielow, director of racing at Chevrolet parent company General Motors, was similarly enthusiastic when the idea was put to him.

“Having Hendrick Motorsports as part of it – they are a great Chevrolet team and have a lot of capability – really brought it all together,” he says. “When we were asked back at Daytona last year, we said yes straight away. It’s great to take the DNA of the Next Gen platform and harden it in a premier race like Le Mans. There is going to be some learning that trickles back into the Cup series.”

The enthusiasm of Button and Johnson matches that of the technical partners. Johnson put his hand up for the project long before the confirmation of the driver line-up in January this year, and prior to announcing that he was calling time on his full-time driving career in the wake of his IndyCar campaign with Chip Ganassi Racing.

"We know we can’t go to Le Mans and park in front of the other competitors in the corners and then leave them down the straights. The ACO is inviting us to be part of their race and we want to be a good-citizen add-on to the event and not be a problem" Brandon Thomas

Le Mans, Johnson explains, is “top of my bucket list” of events in which he still wants to compete. He says that his aspirations to do the race stretch back 20 years: he states that his earliest appearance at the Daytona 24 Hours in 2004 was partially about gaining experience in endurance racing “so if I was ever given the opportunity to go to Le Mans one day, I’d be prepared”.

The last two of Johnson’s nine starts in the Daytona enduro came in 2021-22 in a Cadillac DPi-V.R run by Action Express Racing in conjunction with Hendrick. Rockenfeller was among his team-mates on both occasions. The German became part of the programme after leaving Audi at the end of 2021, and led the development of the Garage 56 racer on both the simulator and the race track.  

Button came into the equation via his friendship with Johnson. When he asked the seven-time Cup champion what he was up to this year and found out about the Chevy Le Mans racer, he caught a flight out to Sebring to watch it test and meet the team behind it.

The test programme began on track in August last year, five months after its announcement in March 2022 as the latest in a line of Garage 56 racers dating back to the Nissan DeltaWing of 2012. But the idea had been in the works for a long time. It was in France’s mind when the Next Gen car produced in conjunction with Dallara was in its initial stages of development ahead of what was initially planned to be a 2021 debut. COVID forced it to be set back a year.

The new car was running only in the virtual world early in 2020 when France suggested that it would be good to give it a whirl in road-course trim around both the Daytona 24 Hours ‘roval’ course and full 8.47-mile Circuit de la Sarthe at Le Mans. That was with a car dubbed internally at NASCAR as Next Gen Prototype 3 (there was no Prototype 2). It was followed by a real test at Daytona with one of the early Next Gen development cars, which was built up by Action Express, the following August.

Johnson will make his Le Mans debut alongside 2010 winner Rockenfeller and Button, back for the first time since 2018

Photo by: James Gilbert / Getty Images

The car was at Daytona to run on the so-called ‘modified road course’ at the self-styled World Center of Racing. It just so happened that the two drivers on hand, Austin Cindric and Felipe Nasr, were asked on occasion to miss out the chicane at the NASCAR Turn 4 to recreate the layout used for the 24-hour IMSA race. 

“We skipped the chicane a few times so we could get an idea of what our pace would be in comparison to an IMSA GT Le Mans or a GTE car,” recalls Brandon Thomas, NASCAR’s vice-president of vehicle design. “We kind of hit our targets from our simulator work earlier in the year, so we thought, ‘OK, we know we’ve got work to do to get in the right window.’”

By ‘the right window’, Thomas means being more or less on a par with a GTE Am car around Le Mans. That’s not just on lap time, but in the way the car achieves that time. He recounts a tale from the initial test of the first Garage 56 Camaro at Road Atlanta in August 2022 to illustrate his point.

“The second day there, Ganassi turned up with one of its Daytona Prototype international chassis, and Earl Bamber came over and told ‘Rocky’ how much he would catch him under braking and through the corners, but when they rolled onto the back straightaway, our car would just leave him,” explains Thomas.

“We knew we had to address that. We know we can’t go to Le Mans and park in front of the other competitors in the corners and then leave them down the straights. The ACO is inviting us to be part of their race and we want to be a good-citizen add-on to the event and not be a problem. To show up and run roughly the speed trace of a GTE car was definitely a requirement.”

Button puts it another way: “We don’t want to get in the way; we want to be respectful of other people’s races.” 

Thomas says that the aim has been to get the Camaro somewhere in the middle of the GTE pack. The target is to be able to lap Le Mans somewhere in 3m58s-4m00s in the race. That compares with the fastest GTE Am race lap last year of 3m50s and the best lap by the slowest amateur driver of 4m03s.

“We knew we had to start tilting the curve down from maximum speed and increase the cornering speeds and decrease the braking distances,” he explains. “We had to improve the car from the vehicle dynamics standpoint. We worked on our targets in terms of weight, engine power and downforce levels; we asked ourselves, ‘How are we going to get this car faster than a Cup car in road course trim and get it into the GTE performance window?’”

Significant revisions to the Garage 56 Camaro include losing weight and gained downforce, fatter tyres, a paddleshift – and headlights

Photo by: Garage 56

Moving the Cup car closer to GTE Am involved the Next Gen racer going on a diet, adding downforce, increasing engine power a tad and going to wider tyres front and rear developed by long-time NASCAR rubber supplier Goodyear, as well as incorporating carbon pads and discs on the standard AP Racing Cup braking system and paddleshift activation on the Xtrac gearbox used in the series.

But there were limits to what could be done because, says France, he wants the fans to be treated to the “full NASCAR experience”. That’s why they will see wheel changes undertaken with trolley jacks a la Cup, and the drivers entering and exiting the car through the window. 

So the Camaro Le Mans racer runs a six-inch flap on the bootlid, what’s officially known as a spoiler but described by Button as a “barn door”. A conventional rear wing, says Thomas, “would definitely have helped in terms of aero efficiency”, as well as being beneficial in terms of tyre degradation.

“The reason we didn’t do it was easy,” he says. “The word from Jim and NASCAR management was that we were going to be taking a stock car to Le Mans, not a GT car.” 

There may be no rear wing, but the Chevy has a lot more downforce than a regular NASCAR racer. There is some trick aero underneath the car, along with some de rigueur flicks and dive planes

The desire to get weight out of the car explains why the Chevy isn’t running a hybrid system. When the programme was announced, ACO president Pierre Fillon stated clearly that it would be required of the car to run a hybrid system, something that was seen as a potential lead-in to the eventual introduction of energy-retrieval technology in the NASCAR Cup. Stielow uses the phrase “directionally incorrect” to explain why it didn’t happen.

“Early on that was the way it was framed up, but really there were a lot of concerns over the mass of the car and intermixing with the other classes at Le Mans,” he explains. “Getting the car lightweighted allowed us to get the car on pace with the GTEs.”

Thomas adds: “The car was at power, but we had to work hard to get the speeds in the corners so we wouldn’t be a hindrance.”

The car weighs in at 1342kg without fuel, which is around 150kg lighter than a road course NASCAR Cup car. The diet yielded a more significant weight loss than that, but some of the lost kilos were added back in as the Camaro was turned into an endurance racer. 

France wants to give fans an authentic view of NASCAR, so pit crew will use trolley jacks to change tyres

Photo by: Garage 56

“We started trimming weight out of the car, but also adding it back in with all the extra systems we have,” points out Thomas. “There are a lot of new systems, like the paddleshift and its electric actuator, new electronics from Bosch and a new refuelling system.”

That’s not to forget the head and tail lights – NASCAR Cup cars don’t have lights!

There may be no rear wing, but the Chevy has a lot more downforce than a regular NASCAR racer. There is some trick aero underneath the car, along with some de rigueur flicks and dive planes. The 5.8-litre push-rod Chevy V8 now produces 670bhp, which is only a tad more than a Cup car in engine configuration it runs on a road course, street track or a long or short oval. 

The first stab at the Garage 56 racer, also built by Action Express, was described as more of a mule and tested for the first time at Road Atlanta last August. The first iteration of the real car to roll out of Hendrick’s workshops subsequently hit the track at Virginia International Raceway in November.

Known as Garage 56/1, it was the first custom-built car for the project and undertook the lion’s share of the development testing before the introduction of Garage 56/2, the car that’s racing at Le Mans. This definitive car proved to be nine seconds a lap faster around Watkins Glen than a pure Cup car. 

The development programme had to focus on reliability as well as performance. The two chassis between them have completed more than 6000 miles of testing. That has included a through-the-night endurance run at Sebring in mid-February, which followed a 12-hour run at Daytona at the start of the month. The car was out on track for 23 hours at Sebring, the only significant downtime coming as the result of a small fire caused by the build-up of spent rubber. Thomas isn’t sure that Sebring was actually the right place to do the test.

“My worry was that the things we were going to break at Sebring weren’t going to be representative of the issues we are likely to have at Le Mans,” he says. “Sebring is all about shaking the car over the bumps, but the suspension on this car is built up from straight-off-the-shelf Cup parts. The sign-off test for the Next Gen wheel- bearing and upright set was eight straight 500-mile races around Dover Motor Speedway.”

Thomas suggests that the engine, developed in-house at GM’s Pontiac, Michigan facility, is of more concern: “It’s an iron-block, single-cam push-rod V8 that hasn’t been engineered for endurance racing.”

Significant testing at Sebring has helped Hendrick prepare for the rigours of Le Mans

Photo by: Garage 56

The aim, though, is to run through to the finish and run strongly throughout.

“We don’t want to be putting the car back together with an hour left just to limp around; the goal is to be out there showing off the car all day and all of the night,” says Thomas. “This car is spectacular when you see the glow of the carbon discs at the front with the exhausts right behind them.

"You don’t normally see cars oversteering at Le Mans – you will this year. The Porsche Curves are going to be a handful" Jenson Button

“The sound is distinctive. No one will appreciate this thing until they experience it: the noise of this thing coming down the pitstraight in between the grandstands is going to mindblowing.” 

It’s going to be wild to watch out in the corners, too, according to Button.

“Every lap feels like a quali lap,” he says. “The amount of steering angle we have to put in… You don’t normally see cars oversteering at Le Mans – you will this year. The Porsche Curves are going to be a handful.

“Everyone will be able to hear it coming a mile off. I’ve had to have different ear plugs made to cope with the noise. The low rumble of the engine of that V8 is awesome.”

Button anticipates the NASCAR will quickly become a fan favourite at Le Mans

Photo by: James Gilbert / Getty Images