Story cour­tesy John “Doo­gie” How­ell of Quad
http://quad.transworld.net/2009/07/02/project-whirl-is-finished/

Pop­Sci staff photographer/madman John Car­nett has real­ized an unholy dream long in the mak­ing: an ATV pow­ered entirely by a jet tur­bine. And then he took it to the woods and pushed it to the limit; to the edge of logic, con­trol and sanity.

As if intent to cement his inter­nal rep­u­ta­tion as the res­i­dent DIY crazy man, Car­nett told me last year that his next project was going to involve a jet tur­bine and some­thing he could drive. Unsur­pris­ingly, Car­nett didn’t feel the least bit ham­pered by the fact that he lacked a tur­bine, a vehi­cle, and any real knowl­edge about how to put a tur­bine on a vehi­cle. But after ten months, untold thou­sands of dol­lars, a big hand from our bud­dies at QUAD mag­a­zine and the equiv­a­lent of a col­lege degree in jet-power gleened from dozens of grizzeld old shop guys around the coun­try, Carnett’s turbine-powered ATV, dubbed the Whirl, ripped up some ground in upstate New York last week, reach­ing speeds of 60 mph and torque that would launch it over an obsta­cle like the Duke boys escap­ing Boss Hog.

The vehi­cle is built around a donated Polaris RZR, a two-person quad that’s been stripped of its engine, roll cage, sus­pen­sion, shocks, bat­tery, drive axels, wheels, tires and elec­tri­cal sys­tem. When Car­nett tried to buy a new tur­bine and explained why, man­u­fac­tur­ers hung up on him, but he soon dis­cov­ered the gray mar­ket of jet-power enthu­si­asts. His tur­bine, a for­mer mil­i­tary pow­er­plant man­u­fac­tured in the 1960s, came from a guy who’d been using it in his Honda CRX and was trad­ing up. The rest of the parts were either fab­ri­cated in John’s Philadel­phia shop, cus­tom made by some­one sym­pa­thetic to the project (like the shocks Elka whipped up just for him) or acquired from the far-flung reaches of the Inter­net (parts for a 40-year-old tur­bine being typ­i­cally out of stock at Lowe’s).

Beside the obvi­ous logis­ti­cal chal­lenges of cram­ming a jet tur­bine spew­ing 1300°F exhaust on a small plat­form inches behind the driver’s head—throwing off the weight and bal­ance of the entire vehicle—and account­ing for an entirely new set of mechan­i­cal and elec­tri­cal sys­tems, is the fact that small sin­gle stage tur­bines like to run at 102 per­cent of power 100 per­cent of the time, but it’s a lit­tle hard to steer a four-wheeler going balls out through the woods (well, for very long any­way). Carnett’s solu­tion (and a good por­tion of the ten-months spent build­ing it): install a hydraulic drive sys­tem in between the tur­bine and the built-in gear box. A sin­gle axis joy­stick style con­troller, like those that con­trol mas­sive min­ing equip­ment, acts as an accel­er­a­tor, adjust­ing the cur­rent flow­ing to the hydraulic pump, which reg­u­lates how much of the turbine’s power makes it to the drive shaft.

After an ini­tial cop-taunting run around the streets of Philly, Car­nett took the beast to the woods for its ini­tial off-road run last week, and sent back this note, which pretty well sums it up: “This past Sat­ur­day I took the WHIRL to a 14-acre area for R&D. The machine exceeded my dreams, scared a few peo­ple and made me smile so hard that it hurt. It’s rather like stand­ing next to a 114db hot dog cooker that could explode at any time: tens of thou­sands of RPMs by your head, 8,000 RPM by your ass. The dan­ger seems to defy the logic of the device. You get into an adren­a­line rush that is unlike any­thing you could imagine—faster thru the woods, mud fly­ing– at the very edge of con­trol; then still faster; you get to the point of almost crash­ing prior to slow­ing down. Lim­its appear; the blurr stops; the tur­bine whine slows; you get out then fall to the ground with a body bruised yet feel no pain…