JCB begins final shakedown tests for record bid

By Greg Fountain

Motor Industry

21 August 2006 10:37

The 1500bhp JCB Dieselmax streamliner will undergo final shakedown tests today, ahead of tomorrow's diesel land speed record attempt.

CAR Online will bring you the news as it happens. Our reporter, Greg Fountain, is imbedded with the JCB team in Utah, ready to provide eyewitness accounts. Keep checking back for updates. The record run is scheduled for 6.30am local time Tuesday, around 1.30pm in the UK. The signs are good: the Dieselmax has already broken the Bonneville Salt Flats course record, with an average run measured at 317mph. On Thursday, the Dieselmax posted a 308mph run; a day later it hit 325mph. The average speed of the two runs was 317mph, establishing the JCB racer as the fastest ever diesel on the course. The official run is timed by the FIA. The streamliner must complete two runs within the space of an hour to post a record time.

It's been a fraught weekend for JCB's would-be record breakers as they hurry to ready the Dieselmax for its official tilt at the speed record. The plan to have the vehicle in fully locked-down fighting trim by the end of last week's Bonneville speed week hit the buffers, because they were unable to get both of the turbodiesels working at the same time. For a while it looked as though the dream could be facing a premature end. 'We just couldn't get both engines on boost and every run was compromised,' said Dr Tim Leverton, JCB’s project director. 'We tried reducing power in the front engine but it merely reversed the problem, and on Thursday morning we had our slowest run. The rear engine was off boost and although [pilot] Andy Green tried every switch on the dashboard, it wasn't working. That was our lowest point. We all sat in the trailer feeling absolutely numb. We just couldn't understand how it worked in testing on the airfield, but not on the salt.'

Engine gurus from Ricardo, who have successfully extracted 750bhp from each of the two engines (which normally produce 140bhp), came up with the solution on Friday, but it didn't come easy. They've had to run a balance pipe from one boost system to the other to transfer energy from whichever engine gets on boost first. This necessitates a whole new starting procedure in which pilot Green has to hold the vehicle at 2000rpm for as long as it takes to get heat into the engines. It's not the most edifying start to the Dieselmax record attempt, especially as Green also has to drag the brakes to prevent premature acceleration. But it seems to work, and with the additional diagnosis of an electronic engine management gremlin all looks set fair for an official attempt.

'It’s a bit trickier making these kinds of adjustments in the field,' said RAF wing commander Green, already the world's fastest man having piloted ThrustSSC in 1997. 'It's an Apollo 13 situation – you have to make use of what you've got, not what you wish you had.' The team will shakedown this afternoon (Monday) and then pack up and move to the slat flats at 6.30am local time tomorrow. Once there, Green will be grappling with another unexpected problem. 'I don’t have a read-out of how fast I'm going because the GPS system they gave us is designed for a car and it cuts out at 223mph,' he said. 'Luckily my fighter pilot experience helps me to calculate the speed in my head.' The team are also awaiting redesigned parachutes after the originals, which were too large, failed in testing.

By Greg Fountain