DELTA WING
more downforce at high ride height than it does when it’s on the deck. And the whole structure attenuates when it gets close to the road, which is a very favourable characteristic we worked very hard to get. At Le Mans you have five straights separated by relatively slow corners. You have to have the car come up into a high downforce position if you can and be low drag on the straights.’ The DeltaWing concept
vehicle was shown with its vertical fin extending past the rear bodywork, but this was trimmed for the Le Mans version. ‘The ACO gave us a very open
brief, but they wanted us to have no bodywork overhang on the back. I said, “okay, we’ll chop everything off.” We have so much stability in hand with the car that it was the safe thing to do. It all ended up working out pretty well, I think. The stabiliser is a yaw device but, more importantly, it creates high pressure on its leading edge, the leading side when the car is in yaw. That’s a really big deal.’
Bowlby took a page out of
Sprint Cup technology by aiding the DeltaWing’s spin-yaw-lift reaction by designing the equivalent of roof flaps for the trailing edge of the car’s under- wing tunnels which means the car could stay on the ground at 200mph and not lift-off. One interesting aspect of the DeltaWing’s aerodynamics involves a piece of technology from 1981 that caught Bowlby’s eye at a time when he was
planning for the car to be used in open-wheel racing. It comes from Dan Gurney’s 30-year old Pepsi Challenge Indy car and its so-called Battery Layer Adhesion Theory (BLAT). ‘After I had a basic package working, and once I’d run a full-scale Windshear to validate the CFD result, I sent a load of work to TotalSim, which included the BLAT design. On the first run they pulled more downforce on the high ride height than the previous sets… it obviously had
a better characteristic because it didn’t have as much downforce at low ride height... They’re not actually skirts, they’re way off the ground. They are vortex leading edges, if you like, delta plan form leading edges. So we developed and optimised that. It was so stable, the flow structure was so robust and it gave the car a characteristic where even in very nose-up angles – if it gets launched off the tarmac or something on the Mulsanne – the car was going to come straight back down. Very satisfying.’
Front suspension has been kept remarkably simple and elegant, with no anti-roll bar, no camber and only 1mm of toe out on each wheel
MOBILE EFFICIENCY The drivetrain for the DeltaWing centred on compactness and lightness to fit the overall concept of mobile efficiency. ‘Zack pretty much single- handedly did the entire gearbox,’ reported Bowlby. ‘He went through a number of iterations to find what we all considered the optimal layout. The design is one that was proposed by Jim Hamilton. It’s a US patent held by Kenny Hill. It’s a unique design and a very clever piece.’
ROAD CAR RELEVANCE – DARREN COX, NISSAN EUROPE CHIEF MARKETING MANAGER, CROSSOVER AND SPORT
‘With our range going forward, a number of the engine applications are becoming smaller in terms of petrol and either turbo or supercharged. Even the Micra will have a three- cylinder supercharged engine. If you look at the Nissan Juke, it has a 1.6 turbo, and everything we learn from this DeltaWing project will be put into that. ‘We are looking at the Juke NISMO, which will be launched at the end of the year, and we will need to know more about making 1.6 turbo engines faster. You could imagine that, as we are in a group, maybe Renault Sport will have the same engines that we are using. We need to be on top of small capacity turbo engines and this is a rapid prototype of that. Yes, it is a race engine, but we are getting our production engineers involved. ‘Don Panoz is not going to
be happy just building one or two cars to do demonstrations. He is talking to us about using the road car engine with more
www.racecar-engineering.com • Le Mans
horsepower as an LMPC engine, for example. Who is to say that the LMPC engine isn’t the same as the Juke engine? Yes, this is a race engine built by RML, but it opens the door to do a lot more. ‘Outside the marketing
benefit, which is just stickers on the side of the car, one of the key things we are using in the company is confidence. We have fantastic products now
Mans, and get beaten up for it, but we have to show our teams that we can take risks, and do some crazy stuff. ‘The product planners that put Qashqai together took a risk. We went head to head with Golf. Everyone said it was a niche marketplace, and we are now, in some markets, outselling the Golf. Sometimes you need to be extreme to prove the rule, and
“Sometimes you need to be extreme to prove the rule”
in Europe. We are selling three times as much as we were four years ago and making more money because our cars are desired by the customers, but we are still not as confident as our market share and our products should be internally. Products like this allow us to bring people on board, not just engineers, but sales and marketing and see that we can be confident. We may only make it an hour into Le
this is what this project does. ‘In terms of transferable technologies, what is road car development going to be about? Downsizing engines is a core part of it and, while we are not going to produce a road car like this, we need to learn about aerodynamics and weight reduction. We have got to get to Le Mans, make the DeltaWing reliable, and keep in line with the philosophy of the
car, which is light weight. We can make it reliable by bulking everything up, make it 20 per cent heavier or whatever, but then you don’t have the car how it was conceived. You have a balance. Downsizing engines, aerodynamics and weight loss are how we are going to have to go, and it is not going to look anything like this, but we will learn a lot of lessons. ‘The original concept was
that we were going to be engine suppliers. We put Ricardo Devila in the project, and he is very influential in NISMO, and knows Le Mans back to front. As he started to feed back to me, we put in more and more resource because we could see that it needed an OEM involved to take it to the next level, and there was advantage to us doing that. It wasn’t the plan originally to be the Nissan DeltaWing… we just saw what a great project it was. If you look at the deal we have done, we are effectively helping them to get to Le Mans.’
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