In initial tests, Eakin’s
gearbox suffered from a number of gremlins related to communications and heat rejection, so a dedicated cooling system is in the works for Le Mans. ‘None of the parts in the gearbox are going to be revised,’ Bowlby confirmed. ‘The shift strategy was just mangling everything. We were trying to make a Cosworth steering wheel talk to a MoTeC data logger and a Live Racing ECU. There were some language barriers.’ Intelligent torque vectoring,
as Bowlby calls it, could also be fully enabled in time for the 24-hour race but, in testing, the team and its drivers were quite pleased with the open differential currently being used. Even the DeltaWing’s engine
is an interesting solution, as it makes use of one of the very few Global Racing Engine designs that have been manufactured.
FIRST CHOICE
‘The engine is supplied by Ray Mallock Ltd (RML) to Nissan,’ explained Bowlby. ‘RML and Nissan have been partners for a long time and RML has developed a four-cylinder, 1.6-litre engine. Best of all for us, they could make it weigh 70kg (154lb) and it would have all the performance and efficiency we were looking for. It’s direct injection, petrol- fuelled and turbocharged. It’s our first choice for what we wanted.’ Named the Nissan DIG-T,
Bowlby is clearly enamoured with the performance and fitment: ‘It makes 2bar boost, has 312Nm of torque in a straight, flat line
and the power rises to 300bhp at 7500rpm. So far in testing it’s achieved 225g/kw hour fuel consumption, which is bloody impressive – that’s like a Prius! It runs on Shell E10 standard Le Mans pump fuel. ‘It uses a two-plate Tilton carbon clutch, separate
has remained untouched: ‘In terms of fuel economy, we’ve taken that aspect of engine development out of the equation. It’s a much lighter car, and we’ve already seen incredible fuel economy as a result. But going forward, that’s an area we want to understand more, and now
“The DeltaWing does not need enormous torsional
stiffness to make it a viable deal for handling characteristics”
alternator, and sits in isolation on rubber mounts so it doesn’t vibrate the rest of the car and gives us a nice, harmonious driving experience. It just does everything you could ask of it.’ With specific involvement
from Jerry Hardcastle, VP vehicle design and development at Nissan Technical Center Europe, RML was able to tailor the DIG-T to the DeltaWing’s unique weight and chassis balance requirements. ‘RML have taken weight out of the engine wherever they can. It comes from modifying cylinder blocks, cylinder head castings, cam covers. Also, they’re trying to drill out the crankshaft so it can be lightened as well. And, in the final modifications, the plenum layout has been changed because of the installation immediately behind the driver within the bulkhead.’ With the emphasis placed
on lightness and reliability, Hardcastle says the DIG-T’s proven direct injection system
that we’ve actually got the car that is an area we can spend more time on.’
COMING OF AGE After two years of intense pressure to bring the DeltaWing to fruition, Bowlby says he took pride in seeing his creation turn, brake and accelerate with the best the factory LMP1 cars have to offer, and was also relieved to have his adventurous virtual concepts deliver as expected on track. ‘It’s been a pleasure, but a great surprise,’ he said. ‘It appears that in this day and age you can predict mathematically the performance of the car, the tyre, the aero and the vehicle handling characteristics. I just don’t think you could’ve done that 10 years ago, maybe even five years ago. ‘I think it’s an incredible
coming of age for the digital computer modelling world. Despite so many people saying it was impossible to achieve, you can still dream in this day and age. We’ve proven it.’ So will a production version
of the vehicle be offered? Project partner, Don Panoz, has said he intends to use his Elan Technologies firm to manufacture the DeltaWing, but what will it cost buyers? Bowlby: ‘If I had to say a
Darrick Dong of DeltaWing brake supplier, Performance Friction
number, it would plus or minus a quarter of a million dollars,’ he said with a laugh. ‘Right now, though, it’s a one off. We’re paying a massive premium on the Aston Martin chassis, so the cost of the prototype isn’t realistic, but it needn’t be an expensive car – the part count is low, there’s not actually a lot of
material in them, there isn’t a lot of tooling. In fact, it’s a very simple car. With a tub of our own, I think the DeltaWing becomes an affordable solution for those who want LMP1 performance with the simplicity of a Formula Ford. That’s our long-term wish.’
TECH SPEC
Engine: Four cylinder, 1.6-litre Nissan DIG-T (Direct Injection Gasoline-Turbo) Maximum power: 300bhp Maximum torque: 312Nm
Dampers: coilover hydraulic
Anti-roll bars: torsion bar rear; no front anti-roll bar
Transmission Gearbox: five-speed sequential Clutch: 4.5in two-plate carbon Shift system: electrically-actuated direct barrel rotation paddle shift Crown wheel and pinion: planetary final driver potentially featuring efficient torque vectoring differential technology
Driveshafts: equal length, tripod- jointed halfshafts
Brakes: carbon / carbon Brake bias: 40 per cent torque bias front Cooling: ventilated uprights, air cooled
Wheels Type: one-piece forged magnesium Size: 15in front; 15in rear
Tyres Front: 10/31 – 15 Michelin Rear: 310/620 – 15 Michelin
Chassis: Target homologated weight: 575kg Type: FIA-homologated carbon fibre monocoque Jacking: air jack
Fuel and exhaust Fuel system: 40-litre, FIA-spec petrol fuel cell Exhaust system: Inconel four-into- one; solenoid-controlled wastegate actuation
Bodywork Tub and body panels: carbon composite
Aerodynamics Twin vortex underbody downforce system, with BLAT (Boundary Layer Adhesion Technology) Centre of pressure: 25% front Coefficient of drag: 0.313
May 2012 •
www.racecar-engineering.com 15
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