Watch This 707-Horsepower Supercharged Hellcat V8-Swapped “Hellkitty” Miata Absolutely Shred

Doesn’t look pretty. Doesn’t care. Goes fast.

byStef Schrader| PUBLISHED May 31, 2019 2:20 PM
Watch This 707-Horsepower Supercharged Hellcat V8-Swapped “Hellkitty” Miata Absolutely Shred

Sometimes I can just look at a car and know that the owner's priorities are right. Between the "Hellkitty" spray-painted down the rear fender and the massive 6.2-liter supercharged Hellcat V8 sticking out of the open engine bay, this Miata's owners are here to party. Priorities, tire destruction. 

YouTuber Karr's awesome Hellcat-swapped Miata is finally running, so That Racing Channel took it for a spin. This is what stuffing five-times the stock horsepower into a little car does: it thoroughly rips. 

The engine came out of a wrecked 2017 Dodge Challenger Hellcat and only really sort of fits in the Miata's diminutive engine bay. The entire transmission tunnel and part of the firewall had to be removed and took two tries to install the engine just where they wanted it to fit. And even then it still stuck up way above where the stock Miata engine would go. That doesn't really matter, though, because who needs a hood, really? 

"It's like with Cleetus [McFarland], you know, he's got those big turbos and stuff," says Karr. "But he's tall enough to see over 'em!" he continued. 

Yet the burnout pad footage proves that seeing really doesn't matter when you're going to smoke out your view with horsepower anyway. 

Karr explains that the entire build took about two and a half months, and breaks down the whole build for us here. There's a Tremec TR-6060 6-speed manual transmission, a differential from a Cobra, Driveshaft Shop axles, a Mopar powertrain control module (PCM) they can use with HPTuners' tuning and data systems, custom headers built by Sideways Fab, and a new intake. It all rides on suspension components from V8 Roadsters and Wilwood brakes allow it to stay in one place for massive burnouts. HPLogic also helped them tune the car, along with a host of other shops and friends who poured their sweat into this thing. 

Right now, it's on Hoosier track tires, which they're quickly turning into smoke. 

They tried to dyno this creation to see how much of that 707 horsepower was really going to the wheels, but the wheels spun every time they tried it—even in sixth gear on their initial run. They were only able to get a 565 wheel horsepower rating on a Mustang dyno with bags of concrete in the trunk—and that was still with some wheelspin getting in the way of an accurate result. They estimated that they could get 650 horsepower to the wheels on a different dyno without the wheelspin. 

It's over 2,000 pounds lighter than the Challenger or Charger that would usually have this engine. They don't list off an exact weight, but if I had to estimate what the power-to-weight ratio is on this now, it would be somewhere between "yee" and "haw."

The car itself was built for fun—both to entertain people on YouTube as well as the owners, who'd like to take it to the track and do other shenanigans. That's why cars really exist, right?