Tuesday, July 7, 2015

The Farce And Failure Of The DeltaWing

I’ve had a couple of guest posts on this blog and here is another. The background here begins with a years long discussion of the Deltawing Racing Program on a motorsports related message board that I frequent. The members of this board are a pretty tech-savvy lot and have highly tuned BS detection faculties. Over the years we’ve watched this program and marveled, not at it’s achievements but that it continues to exist despite an utter lack of them. Matt Miller explains further herein……

The Farce and Failure of the DeltaWing

A Guest Post By Matt Miller

The 2015 24 Hours of Le Mans included some amazing technology and competition among very different LMP1 prototypes.  It also included the first racing of the Nissan GTR-LM, a car designed by Ben Bowlby that is waaaay outside the box.  Against this backdrop, it’s a good time to re-examine another Bowlby design that also diverged severely from general practice: the DeltaWing.  To eliminate all suspense, I will say at the outset that this car is both a miserable failure and a farce.  Now, let’s see why.

IndyCar Roots

To understand the DeltaWing (DW), you have to understand the original intention of the car in 2010: it was supposed to be the next IndyCar.  It was intended to attract attention to that form of racing, which had been losing its fan base and which become a spec-racing series with an old-tech, open-wheel Dallara that was pretty boring.  Bowlby proposed a dramatic new car with only 300hp and which weighed far less than the Dallaras.  It was dramatic because of the shape: with a front track of only 24 inches, the car resembled a slimmed-down Space Shuttle in planform.

The DW functioned as a three-wheeled car, because the front suspension had no roll stiffness, and the front wheels and tires were very narrow compared to conventional cars.  Bowlby claimed that it would lap Indy at comparable speeds to the old Dallara while using half the power and half the fuel.  That mantra continues to be repeated to this day, and it has never been true.  At the time the DW was being announced (2010), IndyCars were restricted to a minimum of 1565lbs for ovals and 1630lbs for road courses. The DW would have had to weigh 800lbs (363kg) to achieve the claimed weight.  In fact, the proposal called for the DW to weigh 1050lbs, which was a lot more than half the weight.  That was the first of many outright lies about the achievements of this car.  We’ll revisit the mantra again later.

Another lie that has been constantly repeated is that the DW looks the way it does because that form provides the best function for a race car.  Yet, in an article by Gordon Kirby (http://www.gordonkirby.com/categories/columns/theway/2010/the_way_it_is_no222.html), Bowlby talks about wanting the appearance of drivers “working in the corners” whereas conventional Dallaras looked like slot cars in action (i.e., they actually have a lot more grip); and how he wanted the jet fighter or the single-seater man and machine entity, [and therefore] developed a single-seater that's very different from what we have today and would in fact be a unique identity.”  In other words, everything was about form, NOT function!  That is the sole reason the DW was developed: difference for difference’s sake.

Supposedly, the DW could match the 225mph lap speeds of conventional Dallaras at Indy because it would have so much less drag, due to its shape and size.  In the Kirby article, Chip Ganassi said, Ben [Bowlby] pointed out to me that an Indy car has more drag than a stock car right now!...That's not the way it should be. But that's how we, as rulesmakers, have allowed it to be.”  This is misleading.  IndyCars certainly have a higher drag coefficient than stock cars, but probably not a higher amount of drag – they have much smaller frontal areas.  Furthermore, while IndyCars are inherently draggy due to their open-wheel and open-cockpit designs (parasitic drag), they also create a lot of induced drag because they make a lot of downforce.  That IndyCars are easily more efficient than stock cars is proved by the lap time comparisons: the IndyCar pole at Fontana in 2012 was 216mph, whereas the Sprint Cup pole was only 186mph despite having more power than the IndyCars (the Cup cars do not run restrictor plates at Fontana).  In other words, the IndyCars of the day were not nearly as inefficient as Bowlby was making them out to be, and they were blazing fast around an oval.  While the DW’s shape intuitively seems to be very low-drag, and reminds people my age of 60s-era fighter planes, Bowlby forgot to mention that it would also have to make downforce to turn fast laps on any track, like any other race car.  That would mean that it, too, would have a lot of induced drag.  To approach 225mph in a straight line in this car with only 300hp would be a huge challenge.  To average 225mph at Indy with only 300hp is simply not possible.

Le Mans 2012

Thankfully, IndyCar did not adopt the hair-brained DW to replace the old Dallara, opting instead for a newer and safer Dallara with factory-option aero packages to make visually impactful cars that are pushing lap records at various venues.  Faced with the rejection of his design, Bowlby decided to peddle it to the ACO to gain entry to the 2012 24 Hours of Le Mans (24LM) as a special “Garage 56” prototype entry.  Key to this entry was that, as a “Garage 56” entry, the DW did not have to conform to the rules of any class (other than safety).  It had no limits, and it had no scrutineering other than safety.  Still, Bowlby and his DW group targeted the LMP1 prototypes much as they had the 2010 IndyCars: by claiming that they are heavy, over-powered, inefficient anachronisms that produce boring racing and don’t push technology that’s useful to consumers.

LMP1 prototypes, the top class of WEC and Le Mans, were factory-backed efforts from Audi and Toyota, with around 520hp and weighing 900kg.  Their power plants and minimum weights were both severely limited by the rules.  The DW was supposed to compete with 300hp and weigh 475kg.  The claim was repeated that the DW would race at half the weight and half the power of the prototypes, and yet go equally fast and use half the fuel.  Without even studying the claims, you can already see that 300hp is substantially more than half of 520hp, and 475kg is more than half of 900kg.  More importantly (you’ll see why soon), 300hp is a whole lot more than half of the 450hp that LMP2 cars were making at the time (LMP2 cars also had to weigh 900kg).  So the lie was cast (see what I did there?) early and often.  As the 24LM approached, the quoted power figures became more fuzzy, with qualifiers like “around” being added into the verbiage, and then 350hp being openly discussed.  In truth, many believe the car’s Nissan engine was pushing closer to 400hp, and there would be no way to verify this because it conformed to no class rules.  The bottom line is that the DW very likely competed at the 2012 with close to the same power as the LMP2 prototypes, but was allowed to race at just over half the weight.  It should have dominated them and even beaten the LMP1s in lap times while still burning less fuel.

So what really happened at the 2012 24LM?  As it turned out, the DW qualified at 3:42.  The LMP1 pole was 3:23, or 19 seconds faster (an eternity).  LMP2’s top qualifying time was 3:38, or five seconds faster.  The DW’s qualifying time would have placed it 16th out of 20 entries LMP2.  In other words, it was an also-ran in a field of prototypes that probably had only a very small power advantage and a huge weight disadvantage.  The fastest GTE car (a production-based car, not a prototype) qualified at 3:55.  The DW was a lot closer to the GTE times than to the LMP 1 times.  To say it was slow would be an understatement.

Did it meet its fuel goals?  No, and again it wasn’t even close.  For reference, the vastly faster Audi e-Tron went 12 laps on only 58L, or about 4.83L/lap. The Deltawing holds 40L of gasoline, and also ran 12 laps/tank too, or about 3.33L per lap: about 69% of the fuel used by the Audi while going much slower.  Supporting this data, it was reported on Mulsanne's FB page that the DW experienced 9mpg and the Audi diesels were at 6.6mpg, or 73% as much as the Audi.  So the DW used 30% less fuel or thereabouts than the Audis. Their stated goal was "half the fuel" and they did not get close to that.  Of course, DW also couldn't do that work in anything close to a competitive lap time. The 2012 Audis could probably have dialed back to 3:42 lap targets and gotten the same mileage, even though they were mandated to weight almost twice as much as the DW.

Since 2012

In the 2015 24LM, the newest Audi R18 lapped at 3:17 during the race, so it has gotten 6 seconds faster and it is using less fuel than in 2012.  The Porsche 919 that won, and uses a 2.0L turbocharged 4-cylinder gasoline engine like the DW, was within a second of the Audi’s best lap and used roughly 5.6L of gasoline per lap to do it, which is still less than twice what the dog-slow DW used.  These cars all use hybrid systems that make a Prius look like a Model T.  They really are advancing technology, unlike the DW, and that technology will apply to production cars in the future.  They look incredible, and they are incredible.  And then there is Bolwby’s newest attention-getter, the Nissan GT-R LM Nismo....more about that later.

The DW has since raced in American Le Mans, which became the Tudor United Sports Car Championship.  You can visit the team’s site here: http://www.deltawingracing.com/.  It now has a coupe roof.  It has become hideous looking.  Nissan bailed on the project a long time ago.  It now uses an engine called an Elan, another 2.0L turbo four-cylinder, with a Mazda DI cylinder head.  It supposedly makes 350hp per their specs, but there has been much talk of it making more like 390hp.  Same old BS.

The DW competes against P2 cars which are essentially LMP2 cars (425hp, 900kg prototypes) that are forced to run Continental tires which impair their performance compared to LMP2s in the WEC.  The DW now weighs 544kg, but probably comes pretty close to the P2 power levels.  It has zero wins, zero podiums, and I’m not even sure it’s ever officially finished a race.  It keeps breaking transmissions, among other parts.  It turns out that building uber-light cars isn’t easy on a shoestring budget.  The tranny failures also probably hint that the team is turning the boost up to try to keep up.  Over time another aspect of the three-wheeler planform has come to light: when involved in collisions with other race cars, it has a pronounced tendency to roll over (see https://www.youtube.com/watch?v=uW7qaG9K2_c&feature=player_embedded).

Myth-busting the Delta Wing

MYTH: Half the weight and power is a novel idea, and other race car designers just haven’t thought of making their cars lighter.

FACT: Every engineer has always known that lighter cars are faster and require less power and fuel.  Every major racing series enforces minimum weights to make sure cars are safe and to keep costs for materials and engineering within reason(ish).  Otherwise, every car would be as light as could be afforded.

MYTH: The DW pushed new technology in materials and construction in order to be light.

FACT: The DW was built on a spare tub from an older, conventional prototype.  It used a nearly off-the-shelf Nissan engine.  It didn’t use any more advanced materials than any other top-tier race car.  And in fact, it keeps breaking transmissions because the uber-light one they’ve been trying to use isn’t strong enough.

MYTH: The active differential is a novel way to make a three-wheeled car handle well.

FACT: Active diffs have been part of racing for many decades now, and their advantages are known.  You won’t find them in IndyCar, F1, or Prototype racing because they are banned by the rules.  If they were allowed, every team would have been using them all along.

MYTH: The Delta Wing has a highly efficient shape that is highly advanced compared to normal prototypes.

FACT: Drag coefficients are nearly meaningless in high-downforce cars, since their aero configurations change so much for tracks and conditions.  Lift:drag ratios are the important metric, and the only number I’ve ever seen quoted for the DW came from the team’s website in 2012, and it was 5:1.  That is, for every 5lbs of downforce, the car induced 1lb of drag.  That’s no better than the best GTP prototypes from 25 years ago!  The only reason current prototypes have lower L:D ratios (typically quoted around 3.5:1, but probably better than that right now) is because rule-makers intentionally hobble aerodynamics to keep speeds in check.  The DW had none of the rules applied to it, and still couldn’t advance aerodynamic technology past the achievements from a quarter-century ago.

MYTH:  The DW can do things no conventional car can.

FACT:  Give any engineer unlimited aero, active differential, 395hp with no other power plant constraints, a weight of 475kg, and similar limitations for track and wheelbase, and he would design a more conventional 4-wheeled prototype that would run circles around the DW and still use less fuel than the DW.  Without going into lots of vehicle dynamics theory, there are sound reasons that nobody designs race cars like the DW.  Remember, the DW was really designed to attract attention with its bizarre looks – going fast had nothing to do with Bowlby’s original intentions.

MYTH:  The DW goes just as fast as other prototypes but uses half the weight, half the power, and half the fuel.

FACT:  No, it does not.  Not even close.  Ever.  Not even once in its four seasons of competition has it even threatened to do this.  The DW has never met a single one of its performance goals…ever.

Why Is the Delta Wing Offensive?

There is no virtue in coming up with a design that is silly and unfounded from the get-go. That's not science or engineering - it's a marketing ploy.  It does actual harm by obscuring good science and people's understandings about vehicle dynamics and physics in general.  Look at how much ink has been spilled giving blatantly false information to the public.  And the half-the-weight-half-the-power-half-the-fuel mantra continues to be stated today!  The DeltaWing group (in all its iterations) is flatly lying about all this.

It would be nice if all the time, money, and attention being poured into this sham could have been diverted into technology that actually had a basis in fact. It would have been a lot better for racing and the advancement of technology.  The DW is a cynical effort and is shaped the way it is for marketing rather than engineering purposes. In 2012, Bowlby took the only Garage 56 entry available, thereby preventing any genuine effort from actually getting a more deserved seat.  The real story on technical advances and efficiency at Le Mans in 2012 should have been the Audis and Toyotas remarkable achievements. But thanks to the DeltaWing, we didn’t hear nearly as much about those real advances as we should have.

The 2015 Nissan GT-R LM NISMO

So this year, Bowlby spearheaded a new prototype to compete in WEC’s LMP1 class: the Nissan GT-R LM NISMO.  This is an interesting effort: extreme, but almost a polar opposite to the DW that he also designed.  The first huge difference is that it will conform to an established ruleset, alongside all the heavy hitters that the DW avoided.  Also, instead of being small, it is as big as the rules allow.  Instead of being light, it has to meet the same 900kg minimum as other LMP1 cars, and in fact has not been able to make that low weight.  Instead of being low-powered and conserving fuel, it was originally intended to push 2000hp (no, that’s not a typo!) using front-biased AWD and serious hybrid technology (the team had major issues with both).  And instead of silly aerodynamics, it goes to extremes in pursuit of something that makes sense on its face: a front-engine layout with the majority of power sent to the front tires in order to make room for exceptionally clean tunnels above the floor and undisturbed airflow under the floor.  The GT-R LM is a head-turner in appearance, but unlike the DW, its appearance does not seem to be a gimmick.

In 2015 the GT-R LM competed at Le Mans without AWD, and it didn’t race with any hybrid power.  So it was hopelessly slow.  But it wasn’t racing as Bowlby intended with all the systems it was supposed to have.  Hopefully next year that will change.  I predict that the severe compromises entailed by this design will outweigh its theoretical aerodynamic advantages.  And I’m not sure that this team can make reliable all the ideas Bowlby has committed to.  But at least it is honest and interesting, and I will be interested to see how it fairs against the competition.


  1. It would be nice if all the time, money, and attention being poured into this sham could have been diverted into technology that actually had a basis in fact.

    This sounds like you are discussing global warming.

    Great post on C & B.


  2. I think its a bit harsh to say that by running this in the 56 garage stopped something of merit being run as the following year the garage was left empty due to a late drop out, at least they came to race and gave us all something else to talk about.
    But I completely agree with everything else you say.