The delta wing concept: revolution or wrong track?

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D he greatest enemy of innovation is sometimes simply tradition . When a new racing car in the form of a four-wheeled tricycle appears in top motorsport, ridicule and malice are probably programmed.

Today, the critics of the Delta Wing concept are reluctant to contact theirs verbal bloodsticks from the spring of the 2012 season when this vehicle stepped onto the sports car stage like a UFO. Because the quirky little car by British designer Ben Bowlby has obviously proven its functionality in racing.

At the 24h race in Le Mans, the American team Highcroft Racing qualified in terms of time in the LMP2 front field. But the big hour of the Delta Wing car struck at the season finale of the American Le Mans Series (ALMS) in Road Atlanta in October 2012: with just five stops and 370 liters of petrol, the 550-kilo projectile covered the 1,000-mile distance - and took fifth place in the overall ranking.

Batmobil has collected design and technology prizes

Since then the Batmobile literally showered with design and technology prizes - even from those who had previously criticized it. Everything according to the motto: What do we care about our chatter from yesterday? The target requirements against which the Delta Wing program should be measured had Designer Ben Bowlby in March 2012 on sport auto already clearly defined: Compared to the conventional prototypes, air resistance, weight, tire wear and fuel consumption should be in the Cut by 50 percent.

How did this revolution even come about? The Delta Wing car was smuggled into the field by the Le Mans organizer ACO with a special permit and only had to meet the safety requirements and the basic dimensions of the current prototype regulations. Otherwise, Ben Bowlby was allowed to let off steam while transforming his original Indy Car project car into a Le Mans prototype.

50 percent more powerful than LMP vehicles

Instead of conventionally generating downforce via wings standing freely in the wind, the downforce on the Delta Wing only comes from the undercurrentVehicle floor - and that has a very low impact on air resistance, which has thus been radically reduced. The reduced air resistance and the improved ratio of lift to drag coefficient means that much less engine power is required to accelerate the vehicle. As a result, Nissan's tiny 1.6-liter engine uses much less gasoline than comparable prototype engines. The radical lightweight construction, in turn, energetically reduces tire wear. All in all, the Delta Wing is in fact a good 50 percent more powerful than comparable LMP1 and LMP2 vehicles.

The eye-catcher of the Delta Wing has always been its triangular base with the bizarre track width of only 60 centimeters on the front axle and the Siamese twin tires, the width of which is just about the same as a stroller: 10 centimeters per wheel. The reason for this arrangement is simple: Because a good 75 percent of the downforce and the vehicle's weight occur in the rear area, the Delta Wing only needs relatively little tire contact area on the front axle. And, logically, the narrow lane drastically reduces the drag in the area of ​​the front end.

These revolutionary framework conditions prompted the Le Mans organizer ACO to place 56th on the grid for innovative vehicles in the 24h race especially for the Delta Wing to shovel free to give Bowlby the opportunity to prove the coherence of its concept on the racetrack. Today it can be said that the full-bodied promises were largely fulfilled. The big question is: what now, what happens next?

Le Mans start was a one-stop-off


It is still completely unclear how things will continue from 2014, but the improvement in the Delta Wing concept for customer sport use is already running at full speed. “There's a much better Delta Wing in the current Delta Wing,” said Ben Bowlby at the ALMS final in Road Atlanta. The cheeky Briton has already completed his to-do list - and much of it should be implemented for 2013.

The monocoque offers by far the greatest potential for improvement: the ambitious schedule for a Le Mans start To be able to meet at all in 2012, Ben Bowlby resorted to an Aston Martin LMP1 chassis from 2011. This saved the costly crash tests and a lot of time, but it was boughtThere is also a disadvantage in terms of weight distribution: 'By using the AMR-One monocoque, we also lost around 20 to 30 percent downforce,' says Bowlby. “In general, the monocoque is too wide for our needs. And some details on the underbody prevented us from fully implementing the concept of generating a lot of downforce from the undercurrent. '

A further development of the front suspension was already tried out in Atlanta: but unfortunately the steering became so hard and numb that we had to reduce the values ​​again ”, regretted Bowlby. All of these problems could basically only be solved with a different monocoque. The Drag Reduction System (DRS) derived from Formula 1, which played a major role in increasing top speeds on the ultra-long straights at Le Mans, could also be extremely improved.

Limits of the Delta Wing Concept

The spectacular rollover of Delta Wing pilot Gunnar Jeanette during free practice in Road Atlanta also showed the limits of the concept : The contact with a careless Porsche pilot pushed the Delta Wing into a sideways roll without a trace. 'The accident was something like the perfect storm for us,' regretted Ben Bowlby. “Because the contact was made with 4.5 g and in the most unfortunate angle. Because the Delta Wing on the front axle is de facto lacking support from the opposite wheel due to the narrow track, it is more susceptible to tilting. So the rollover was not completely unexpected. ”

The engine is also a problem with the further development, because Nissan stepped into the breach as an engine supplier at short notice - but the deal was only valid for 2012. So it is likely that Nissan will end its not inconsiderable technical support The financial contribution from Nissan - rumored to be two million euros - will also disappear in 2013.

The Japanese had Chevrolet's Global Race Engine for the Delta Wing program, which is used in the TW World Championship , refined and optimized together with RML and with our own components. Progress has been made especially in the area of ​​lightweight construction: The weight of the crankshaft has been reduced to 7.8 kilograms, for example.

'At 2 bar boost pressure, the engine develops 320 hp at 7,500 revolutions,' says Bowlby. The implementation of the power to the wheels was, by the way, quite a flop despite all the obvious successes, because the torque vectoring differential, which among other things was supposed to cure the driving dynamics compromises of the different track widths between the front and rear axles, never worked, contrary to all official statements. Even worse - it was never used in racing. To this day, the Briton is most of the efficiency of theFour-cylinder turbo engine impresses: 'During test drives in the summer of 2012 in Road Atlanta we achieved a specific consumption of 225 g /kWh, and that with extremely competitive lap times!'

All the more regrettable that the Delta Wing makers now have to look around for a new PS supplier for the 2013 customer sports program. And in view of the multitude of possibilities for improvement, the question must be allowed as to whether the largely privately financed project can still play an essential role in motorsport: Where should the money come from? The project is also about to end in the medium term because the ALMS merged with Grandam in 2014 - and then the last playground for the Delta Wing could finally be eliminated. And all this despite the fact that the Delta Wing has achieved its core goals in terms of weight, aerodynamic drag, downforce, power and consumption as well as tire wear.

The Delta Wing is a disruptive technology

The overall assessment of the Delta Wing chapter is almost philosophical. Former FIA consultant and ex-F1 engineer Peter Wright considers the Delta Wing to be an example from the “disruptive technology” category: “In contrast to sustainable technology, disruptive technology is mostly designed by small companies or design groups. It very often results in radical and innovative new approaches, sometimes even real revolutions. But because such solutions often have no practical justification in the corresponding environment, these innovations often disappear as quickly as they came. ”

Wright's interpretation unfortunately sums up the short history of the Delta Wing concept very succinctly together. The best evidence for his thesis is the fact that the technically revolutionary concept of the Delta Wing will not leave any lasting traces in prototype sport. Because the biggest defeat of Bowlby & Konsorten is that nothing, absolutely nothing of the innovative approaches has flowed into the new prototype regulations for the 2014 season.

In fact, the opposite is true: The lightweight Delta Wing has proven how much energy can be saved through lightweight construction. In the new regulations for 2014, however, a tentative weight reduction is anchored at best, which has just been partially thwarted by an increase in the base weight for LMP1 vehicles to 870 kilos.

The major manufacturers that are factory involved in the LMP1 class have repeatedly pointed out at the ACO that a car like the Delta Wing, which is completely outside of the current technical regulations, cannot be compared with their vehicles. The lobbying work was successful, and from their point of view the Delta Wing was probably nothing more than a “disruptive technology”. Sometimes the greatest enemy of innovation is simply the persistence of tradition.

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