JCB Dieselmax
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The JCB Dieselmax is a diesel-engined 'Streamliner' car designed for the purpose of breaking the land speed record for a diesel-engined vehicle. The chassis was designed and built by Coventry-based engineering company Visioneering, with engine development by Sussex-based Ricardo UK Ltd. During the 2006 Bonneville Speed Week and subsequent FIA record runs, the car was driven by Wing Commander Andy Green, a serving RAF Officer who previously broke, and still holds, the absolute land speed record in the ThrustSSC.
The car itself is powered by specially-tuned versions of the production JCB444[1] powerplant, developing up to 750 bhp each (over 5 times the power output of the production version) and featuring 4 cylinders and 5 litres of displacement, accompanied by two stage turbochargers, intercooler and aftercooler. One of the dual engines drives the front wheels while the other drives the rear[1]. Each engine is rev-limited to 3800 rpm. As the size of the car prohibited meaningful wind tunnel testing, the streamlined shape of the car was refined entirely though the use of computational fluid dynamics by MIRA Ltd, which has enabled the car to obtain a very low coefficient of drag of only 0.147 and a CdA value (drag coefficient × frontal area) of only 0.129 m². The fuel tank, which holds only 9 liters (2.38 gallons), is located directly behind the carbon fiber cockpit[1]. The fully-laden weight of the vehicle, including fuel, oil, ice, water coolant and the driver, is only slightly less than 2,700 kg.
The car began shakedown testing on July 20th 2006 on the runway at RAF Wittering with the lower-power 600bhp version of the JCB444 engine, the team slowly ramping up the speed to prove the chassis and engines. They eventually achieved a speed of over 200 mph on July 30th. Two days later, the car was disassembled ready to be flown to Wendover Airport, Utah, former home of the B-29 'Enola Gay' on August 8th. On August 13th, after several days spent re-assembling and re-testing the car, the Dieselmax made its first official run on the Bonneville Salt Flats as part of Speed Week, eventually attaining an average speed of 317 mph to take the SCTA-BNI event record for an 'AA/DS' Diesel Streamliner.
On 22nd August 2006, after being re-fitted with 750bhp 'LSR' versions of the JCB444 engines[1], the JCB Dieselmax car broke the official FIA diesel engine land speed record, attaining a speed of 328.767 mph (529 km/h). 24 hours later the JCB Dieselmax car broke its own record, achieving a speed of 350.092 mph (563.418 km/h) over a distance of 1 mile[1] on 23rd August 2006[2]. Before attaining these speeds, the Dieselmax was pushed from behind, by a JCB Fastrac, until it hit 30mph where it engaged first gear[1]. Before the JCB Dieselmax records, the diesel land speed record was 236 mph (380 km/h), set in August 1973.
In a live interview from Utah on BBC News 24, Andy Green said that the car was not running at its full potential, due to problems finding suitable tyres and that this speed was achieved while the car was still in fifth gear (the car has six). He also reported that the vehicle traveled 11 miles (18km) on about a gallon (3.8L) of fuel. The fuel tank holds just nine liters while the ice tank, used for cooling, holds 180 liters.
Although JCB have not made any official statements on the subject of a return to Bonneville, JCB Group Engineering Director Tim Leverton has hinted that they are currently studying the development of tyres that would allow them to overcome the nominal 350mph 'safety limit' they had placed upon their current Goodyear units.
[edit] See also
[edit] References
- ^ a b c d e f Masamitsu, Emily (2006), "Diesel Refined", Popular Mechanics 183 (12): 23, ISSN 0032-4558
- ^ BBC News, JCB car breaks own speed record
