The power: Yep, Tantrum has 1,650 horsepower. That's more than two Hellcats worth of power under the hood. It's a twin-turbo 9.0-liter Mercury Racing engine with a quad-cam four-valve setup. Basically, it's a V8 boat motor developed for cars. Mercury Marine is the crew that developed the V8 for the 1990s Chevy Corvette ZR-1. That all-aluminum LT-5 under the hood cranked out 405 hp – an astronomical figure for the time – and helped make the ZR-1 an icon.
Take a listen to Tantrum's 9.0-liter Mercury mill below.
Who's behind all of this? SpeedKore, a Wisconsin-based performance shop that does one-off pro touring builds. It specializes in remaking Detroit muscle with modern features like carbon fiber, bespoke interiors, and powerful engines. SpeedKore is pretty good at it. Before it threw a Tantrum, it did the "Cudinator" used in some of the Fast and the Furious movies.
You might not know: Tantrum won the Best Domestic category of the GT Awards at SEMA – chosen by your author. The sinister looks were the hook, and the crazy engine solidified its performance cred.