How A Tesla "Engine" Swap Saved This Classic Porsche 911 Race Car

The unique, floating physics of the classic Porsche 911

This 1976 Porsche 911 has an interesting story, to the point where people say it’s "cursed". The car started life as a street car but was later converted into a race car by John James Racing, which is where it got its wide-body kit. An older iteration of the same car can still be seen on their website. Later, the classic 911 was converted back into a street car, but with most of the performance goodies still in place, including the original, mildly modified, air-cooled, Porsche flat-six engine.

Chris from Ruffian Cars explains that when the mudslide happened and filled the garage housing the Porsche, the car floated because of its "bathtub bottom”. The exhaust and in turn, the engine was filled with mud and that was it for the air-cooled boxer unit. At the same time, Chris was in talks with Electric GT to do an electric conversion, and although the classic Porsche wasn’t the first candidate, it ended up receiving the electric “engine” swap. This is hardly the first Porsche 911 EV conversion, I have seen. Companies like Kalmar Automotive and its 7-97 E-Volt that costs nearly half a million dollars is readily available, but this one has, by far, the most interesting story of any EV-converted 911 so far. The apltly named Sacreliege Motors, has also showed off a Tesla-powered 911 last year. Then, there are other weird engine swaps, like the rotary-swapped Porsche 911, which I covered not too long ago.

Despite the Tesla powertrain, the 911 retains much of the original car’s driving dynamics

The car, dubbed eGT-913, was originally unveiled at the 2021 SEMA Show at the Electric GT stand. The car crashed three times before it was finally rebuilt in its current form. The hood, front and rear fenders, rear bumper, and rear decklid are made out of fiberglass, and there are carbon-fiber side skirts to make it a bit more exotic. The roof, doors, and cowl are still steel. Despite that, the Tesla-swapped Porsche tips the scales at 2,800 pounds, making it much lighter than any other B.E.V., currently on sale. Moreover, the classic 911 E.V. build makes the heavyweight Porsche Panamera Turbo Hybrid look like a real porker.

In addition, the weight distribution of this classic 911 EV build is very similar to an original, 930 Turbo, at 38/62 front to rear. Back when the car was showcased at the 2021 SEMA show, it was roughly 500 pounds heavier, so some serious weight-shaving has been done since then. Another obvious difference is the lack of a ducktail rear spoiler. All cooling ducts you would normally find in an air-cooled 911 have been shut since there is no need for them with the electric drivetrain. The car even does a neat torque squat, similar to a 930 Turbo, minus the turbo lag. Another authentic feature that has been retained on the Tesla-swapped 911 is the original non-power-assisted Porsche steering.

Race car looks inspired by old-school Porsche 911 racers

The mostly fiberglass body is finished in bright orange with black accents, featuring what Chris describes as a “lesser imp” (a creature that serves the devil). The wide-body features very exaggerated rear fenders with massive air ducts in front of the rear wheels and air extractors on the aft. The general aesthetics can be described as a mix of Porsche 934 and 935, minus the massive rear wing. Lauern Teile custom taillights complement the tastefully-modernized, round 911 headlights that now feature LED lighting. Lexan glass further enhances the car’s competition looks while dropping a bit of extra weight.

The no-nonsense race car theme is just as apparent inside the cabin, which can best be described as spartan. A digital gauge cluster, massive roll-cage, racing bucket seats, and zero sound-deadening are all part of the diet. There are few buttons for the essentials, but the most interesting one is the valve adjustment for the rear brake bias, which is neatly labeled “less” and “more”.

Making the Tesla drive unit play ball was tricky

You have waited long enough, so here I am at the point where I have to tell you how the Tesla-swapped Porsche 911 works, and what trouble the team at Ruffian Cars went through to make it work properly. The drive unit is from a Tesla Model S, but it’s not the crazy, Plaid variant that makes over 1,000 horsepower. The drive unit produces 450 horsepower and 332 pound-feet. No performance figures are given, but it’s enough to get the lightweight Porsche 911 to some serious speed in a very short time.

The kit that costs $69,995, comes from Electric GT, and mounts on all the factory mounting points, meaning no structural modifications are required. The battery pack is divided into two sections, one in the rear and one in the front, for better weight distribution. The battery pack and electric motor are water-cooled, which will surely ruin the day of any classic Porsche 911 purist.

The tricky part was the open differential that comes on all Tesla drivetrains, which made the car unpredictable. The issue has been fixed and the car now features a limited-slip differential along with Elephant Racing suspension. There are also massive slicks, with 275 sections at the front and 335 at the rear. Due to having instant torque, no traction control, and no gears, once the tires break traction, they really start spinning and don’t stop even after you depress the throttle.

They’ve managed to go around this by tweaking the regenerative braking function to act as an engine brake, making the car more manageable and recuperating energy that would otherwise be lost. This classic Porsche 911 race car build is definitely one of the most controversial ones out there. At the end of the day, it is a fun toy to hoon around in, and that’s all that matters.