By Archie Bosman, October 24, 2014

Salt Flats

On the occasion of its piston-engine wheel-driven record breaking run, during Bonneville Speed Week 2013, the Speed Demon averaged 437mph over the measured mile in a time of 7.8sec. Achieving entry and exit speeds of 452mph and 462mph respectively, over the longer FIA distance the Speed Demon’s exit speed is expected to be 482mph, subject to traction.

Bonneville, UT: On September 12, 2014 while hurtling along the Bonneville Salt Flats about three miles from the starting point, the intrepid George Poteet lost control of the Speed Demon, which flew 550ft distance before crash-landing on its side. Though bruised, the Land speed record holder Poteet was unhurt.

At the time of the incident the vehicle’s wheel speed indicator revealed a velocity of 370mph.

Given that the twin-supercharged V8 Speed Demon spins its wheels under acceleration up to and beyond 400mph, tail-wagging is the constant plight. The trick is to introduce the motive power to the salt surface as gently as possible. Of the three engines available to power the car on this occasion, it was running the one generating the most torque.

In common with this year’s Bonneville Speed Week, which was cancelled a month earlier due to extensive rainfall, the September FIA meeting didn’t materialize either and instead was reduced to a test-and-tune session. Though conditions had improved the Speed Demon needs 12 miles of satisfactory surface on which to operate.  

So the plan was to run the car up to around 450mph over 5.5 miles. Then deploy both parachutes, using the remaining two miles to bring it to a stop, and monitor the data acquired. In the event, no engine or drive train damage was sustained, although the bodywork and chassis didn’t fare so well.

KennyDuttweilerSignificantly, discussions regarding upgrading the car had been on-going for a year. Now as a result of the accident, the decision about how to proceed will be taken in about a month’s time. In all likelihood the chassis, which is around 230in long, will be replaced with a new revised model. To improve weight distribution and handling, plans are being considered to move the motor forward by around 12 to 14in. Fluids will be lowered.

Over the past five years the car has gained around 500 to 600lbs; it now carries 20 gallons of fuel, 20 gallons of coolant, and 20 gallons of intercooler water. In addition the fiberglass body will most likely be replaced by carbon fiber.

Engine power has been provided by Ken Duttweiler Performance located in California. Duttweiler, a supremely skilled operator, has been increasing engine output since the beginning of the Speed Demon program while toiling for softer torque delivery. His approach has long been reminiscent of that of Jim Hall of Chaparral Cars: “When nothing breaks I have nothing more to learn.”

Fox News reported the story with a video of the Speed Demon’s accident which can be viewed here.