Zach Bowman of Exhaust Note, Hooniverse, and others, found this video of the crazy-ass Hyper PRO Racer, a go-cart with a Yamaha 450R ATV engine in it. It’s fast. Real fast.
The thing has an egg-shaped full tube steel frame, inboard suspension, and disk brakes. It weighs 350 pounds dry. And it’s, like, a millimeter off the ground. It’s for sale in Australia for $29,500 AU, which is currently about $26,350 US. That’s a lot of scratch, but it’s also a lot of track-day fun.
Sources: Exhaustnote, Hyperracer.com