Swapping a monstrous engine into a smaller car is nothing new. Swapping a 6.2-liter supercharged V-8 known to most as the Hellcat into a Mazda MX-5 Miata, however, is.
That was YouTube channel KARR’s most recent project, which Motor1 first reported on last week, a project that went rather swimmingly despite all of the work required. The channel documented the entire process in a four-part video series and the amount of effort required to make the Miata Hellcat come to life is rather intense. Yet, it’s oh so satisfying to see the engine stuffed under the hood.
The MX-5 Miata used is an NB-generation car, which means it came from the factory with a 1.8-liter inline-4 engine that made 140 horsepower. Now, the car features 707 horsepower at its disposal, and that’s before the crew starts to tinker with the engine. The powertrain comes from a wrecked Dodge Challenger SRT Hellcat the crew brought to the shop to begin the Frankenstein-like project. Also new to the Miata is the rear end (a Ford 8.8-inch), coilover suspension, and stronger internals to ensure the tiny roadster can handle the gobs of supercharged power and extra weight.
KARR then tapped V8 Roadsters for a new crossmember to hold the big engine in place before the crew removed the interior to widen the transmission tunnel. As it stands, the engine and transmission didn’t fit the Miata’s rather dainty transmission tunnel, which led to some serious fabrication work. When all is said and done, the team lowers the Miata down onto its new heart and it fits rather well. It’s not a perfect fit, which no one expected, so it will be very clear this isn’t your typical Miata. The crew is now working to make everything operate in concert for one lightweight all-powerful roadster.