There could be a new speed record established for alternative fuelled cars at Shakespeare County Raceway’s opening meet of the season following successful tethered tests of a unique rocket powered dragster; ‘Laffin Gas’ at a remote farm in Northamptonshire.
Powered by a mixture of liquid nitrous oxide and vegetable oil the Laffin-Gas rocket dragster is the brainchild of David Knight and Carolynne Campbell, who are confident that the technology could equally be applied to rocket-assisted take-off of aircraft and UAVs.
At the recent Southern Manufacturing and Electronics Exhibition, Chief Engineer Knight (who comes from a race engineering background) explained that the four rocket tubes are lined with thick cardboard, soaked in oil. “That’s biofuel,” he points out. “Our dragster is capable of producing 4000 to 8000 lbs of thrust, and has a power to weight ratio that is four to five times that of a Formula 1 racing car, yet it’s designed to be reliable and re-used over and over again.”
The nitrous oxide is held in four high-pressure cylinders, one for each throttle valve and motor. The valves are solenoid operated and open against the flow of the liquid. Any interruption of electrical power causes them to shutdown instantly. The nitrous oxide is pumped into the rocket motors by weight, so as to equalise the running time and pressure profile of each tube. The pyrotechnic charges that start ignition are set off by glow plugs.
Carolynne, who is the driver adds: “We want to be able to do it regularly and as a reliable performance. We got the idea about four years ago, when we saw a tiny rocket car at a track. It made lots of noise, but it wasn’t very quick. We built our dragster ourselves and it works,” she said.
“This weekend we are hoping to set an early benchmark for the top speed of over 200 mph for a bio-fuel powered car,” Carolynne added. “This will also be our first chance to test the new pilot ignition set-up which performed so well in recent tethered testing.”
The two day event at Shakespeare County Raceway, Long Marston Airfield also holds the first anniversary for the Worcester based JapMids.com car club where they will be finding the quickest Japanese car of the weekend as well as contesting a number of prizes in a ‘Show & Shine’ competition.