Top 10 Coolest Backyard Inventions of 2008: DIY Rally

16Dec/090

Top 10 Coolest Backyard Inventions of 2008: DIY Rally

Jet-Powered Go-Kart /// Bryan Midgley /// Naperville, Ill.

What It Is: A go-kart that can lap a suburban block in seconds (and effectively drown out the neighbor's dogs)
Time: 300 hours over about 10 months
Cost: $1,000

A jet engine might seem like an excessive source of power for a go-kart. And it is. "It's scary—better put, terrifying," says Bryan Midgley, 37, of driving his one-person vehicle. "You're being propelled by an engine that's screaming 10 or so inches from your head." An assistant manager at a Mitsubishi dealership—and self-described junk hoarder—Midgley hand-built the go-kart's body and much of the engine from scrap. he turned an old fire extinguisher into the casing of the combustion chamber, for example, and the outer casing of a Mitsubishi Galant catalytic converter into the flame tube inside the chamber. he found the power turbine on eBay. its planetary gears, set at an 18.3:1 ratio, reduced the output from 62,000 rpm to a more sane 3250. even so, the first test run, in Midgley's Naperville, Ill., neighborhood, revealed a dangerous glitch: The 100-hp engine's massive torque (300 lb.-ft.) overwhelmed the brakes. Midgley harnessed the power with a custom clutch system. Still, the nearly 500-pound go-kart accelerates briskly, zooming from 0 to 60 in about 8 seconds. "I set the gear ratio so speed tops out at around 72 to 74 mph," Midgley says. "I got it to 67 mph and then ran out of courage, not speed." Translation: Don't try this at home.

Top 10 Coolest Backyard Inventions of 2008: DIY Rally