The picture you see above is the car which will bridge racing’s past and future, and may be the most exciting thing to happen to motorsport in decades. This is the Green4U Panoz Racing GT-EV, an all-electric racecar intended to compete in next year’s Le Mans 24 Hour race, motorsport’s most grueling test of endurance. The car will be entered for consideration as the race’s “Garage 56” entry – an “exhibition” slot with relaxed rules which is reserved for a car which displays innovative new racing technologies.
While other electrified vehicles have competed in Le Mans (hybrids have won the last 5 races and are expected to win this year’s race, happening this weekend), the GT-EV would be the first all-electric car to attempt the race. In 2014 Nissan entered the “ZEOD RC” as the race’s Garage 56 entry, which was a hybrid with a battery large enough to do a full lap under only electric power.
The car
A collaboration between Panoz racing team and Green4U Technologies, the Green4U Panoz Racing GT-EV is intended as a competitor in the GT racing class, which pits modified road cars against each other (as opposed to “prototype” classes which are purpose-built racecars not meant for the road). Typical cars in the class are the Porsche 911, Corvette, Ford GT, Ferrari 488, etc. While usually “Garage 56” entries compete as prototype cars, Green4U claims that they intend to make a roadgoing version of the GT-EV in the future.
The car’s specs have not been finalized, but it is expected to have 530-600 horsepower, a 175-180mph top speed, and utilize all-wheel drive from two electric motors, front and rear. The car should weigh 2,200-2,750lbs all told when finalized, including the battery pack. Clearly they haven’t yet finalized what type/size of battery pack they’ll be using, given that their weight estimate has such a wide range. To keep weight down, the body is made of carbon fiber, and because the battery mostly occupies the right side of the car, the passenger compartment is offset to the left side of the car, with driver and passenger arranged in a “jet fighter-style” cockpit.
These specs (in particular the weight) probably won’t carry over into the roadgoing version of the car, if it ever gets made, though Panoz says the car would end up costing $100,000-$200,000.
The race
The Le Mans 24 Hours race is one of the most famous races in the world, and is considered the most difficult race on both car and driver. Cars have to run for 24 hours straight, only stopping for occasional pit stops to refuel and change tires, and each team has three drivers who swap out driving duties. By the end of the 24 hours, the winner will have driven over 3,000 miles/5,000km, a large majority of which is at full throttle. The race is fraught with peril, with mechanical failures and crashes being very common. It’s the ultimate test of speed, efficiency and reliability, for both car and driver.
Contrast this to the current offerings in electric racing. Quarter-mile and single-lap times for EVs are great, but a race requires more than that.
Formula E – a series which has beat motorsport audiences’ expectations by offering captivating close racing and an impressive driver lineup – nevertheless still needs two cars in order to finish an hour-long sprint race, with drivers swapping cars mid race in lieu of a traditional refueling/tire-changing pit stop. And while competition has not yet started in the Tesla Model S-based Electric GT series, those races are only planned to be ~37 miles (60km) long, a far cry from the 3,000 miles of a Le Mans race.
The difference, of course, is that batteries are less energy-dense than gasoline and generally take longer to charge. Even with the better torque and responsiveness and much higher efficiency of electric motors, EVs haven’t yet been able to make up for the demands an endurance race requires of them. During a Le Mans race, a finishing car will stop around 30 times for refueling, approximately every 45-50 minutes. This means a car needs to be able to do about 100 miles/160km per stint in order to be competitive – and the heavy braking and acceleration and high speeds of a Le Mans race do not do wonders for any car’s efficiency (the winning hybrid last year got about 6 miles per gallon).
So Panoz/Green4U’s mission here seems crazy, right? Surely some sort of new breakthrough in technology would be required to make it work? Well, not so fast. They think they can pull it off, and so do I. The idea which makes this possible is one we’ve already seen before: battery swapping.
How do they do it?
While it is true that gasoline can be added to a tank faster than electrons can be added to a battery, a car can be designed around the idea of hot-swappable batteries to allow much faster “refueling.” The GT-EV takes this into account, by having the ~1,000lb battery situated on the right side of the car in a “slot” which could be changed out by a pit crew, with a little mechanical help.
Le Mans is the right series for this, too. Formula 1 does not have refueling stops, but their tire pit stops involve a crew of ~20 people changing all four tires of the car in around three seconds. In Le Mans, rules state that a maximum of five mechanics can work on the car during a pit stop, the car must be turned off before work can start, and that no other work can be done on the car during the refueling process (wherein the fuel flow rate is limited to a fairly glacial pace anyway).
This leads to significantly longer pit stops, generally almost a minute long. So between this longer timeframe and the idea of swapping rather than charging, “refueling” an electric car starts to seem possible. And being required to turn off the car before work starts means pulling the battery out isn’t a big deal, since the car was going to be turned off anyway.
Now, since we know that we can refuel the thing, we just need to make a car that can go a full stint on one charge, and keep it light enough to still be competitive. Green4U claims the GT-EV can do 90-110 miles in “race conditions,” which is about the same distance as an average stint for a Le Mans car (100-110 miles).
To achieve the efficiency required for this range, the GT-EV uses active aerodynamics to reduce drag on straightaways while maintaining downforce in corners, and regenerative braking on both front and rear motors to help recuperate energy which would otherwise be lost in braking. Applying these technologies to the inherent efficiency of an electric motor will help get them closer to their goal of ~100 miles per charge.
CAN they do it?
It remains to be seen how all of this will play out. The car still needs to be engineered, built, put through the crash tests required to make sure it’s safe enough to race, and the ACO, the group which organizes the Le Mans race, needs to decide it’s worthy of next year’s Garage 56 entry. Not every year has a Garage 56 entry, either because nobody comes up with a concept interesting enough to merit it, or because the concept which gets chosen ends up having budget problems (as happened to this year’s biomethane-powered project).
The GT-EV’s concept is obviously a shoe-in for Garage 56 – it’s unlikely anyone could come up with another concept more worthy of the “innovative experimental racecar” badge. Don Panoz, owner of the Panoz racing team, stated that considers this project to be his “Holy Grail of racing.” But if the ACO decides that the project is too unrealistic, or that the budget for the project isn’t there, they may choose to go another direction so as not to get burned two years in a row by a dropout.
While the concept behind the GT-EV seems realistic enough to me – personally I’ve been waiting eagerly for years for someone to apply this concept to Le Mans, since it seems very well-suited – the numbers will be difficult to obtain. It’s going to take a lot of work to make a car which can produce 600 horsepower, weigh under 3,000lbs, and carry enough energy to do a full 11-13 lap stint around Le Mans’ Circuit de la Sarthe.
But if they do pull it off, it will change racing forever.
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