Delta Wing Discussion ONLY

[Maelochs]

You should buy him a DeltaWing.

[Machin]

Originally Posted by HJJ

The cars at Conti's Monday test after Petit are documented elsewhere. I'm not going to give out times because trusts would be broken. As I said they were in the mix with the P2's times.

According to this article about the Daytona Prototype Evo:- http://sportscar365.com/features/pho...prototype-evo/

"The DeltaWing, running on Continental tires for the first time, as well as an undisclosed GT Daytona car, which turned its first laps in America, were also on hand at the test Monday."

This suggests that there were no P1's or P2's running in the test? Can you confirm that?

[Machin]

Originally Posted by miatanut

The idea was never to beat the power:mass of other cars. It was to get a driver around the course at a speed between P1 & P2 using half the fuel.

Since Power is kilowatts and that is Kilojoules/second, and fuel is Kilojoules/kilogram, we can roughly approximate a car's power (multiplied by the % of time spent at full throttle) to it's fuel consumption. I.e. a car with 500bhp and spending 80% of a lap at full throttle will roughly approximate to twice the fuel consumption of a car which has 250bhp and also spends 80% of its time at full throttle, assuming both achieve the same lap time.

An LMP2 has ~450bhp, and the Deltawing has 350bhp, and it can't achieve the same lap time. So you have to guess it is using about 77% of the fuel of an LMP2 to not achieve the same time. Even at Le Mans, where the long straights help it, it still had 300bhp (66% of the LMP2 power).

The next question we have to ask ourselves is "Is it reasonable to expect a car which (they claim) has half the mass and half the drag, to achieve an equal lap time on half the power"?

Yes we should: Newton's second law states that F=mA, or rearranged to A=F/m. In words that is: "If the ratio of resultant forces acting on a mass is the same as the resultant forces acting on a different mass, both masses will accelerate at the same rate", in the context of a racing vehicle Newton's second law says that a car with half the mass, half the drag and half the power will have the same acceleration (and hence lap time) as one with twice the mass, twice the drag and twice the power.

The difficulty of course is designing a car that will transport one person, whilst meeting the safety requirements, and still achieve the half-half-half challenge. To be honest, I don't care about the half-half-half thing. If they'd managed to achieved 75%-75%-75% with the same performance I would call that a "win" (at the very least they would have proved Newton's second law, if proof were needed!), but actually they've not even managed to achieve the same performance with the mass-drag-power ratio somewhere nearer 60-60-77. That in my mind is clearly a fail.

Especially when you consider that the other cars are built to strict rules, and this is built with complete disregard to those rules (except the safety ones).

If for example we suddenly allowed LMP1's to use ground effects tunnels (like this has), we would expect it's performance to be way above the current performance curve, would we not? The delta layout is way below the curve.

[Maelochs]

Yes, Machin, and as I an others have been saying, maybe if the DWing got even a fraction of the development time and budget of say, the P2 cars it beat at PLM in 2012, we might see that the general idea of a smaller, lighter, wingless car using less fuel can achieve the same performance as a heavier, more powerful conventional car, but since it has always been run on a shoestring, we cannot know.

The most talented amateur, using lousy equipment and with no coaching, will always look weak compared to a well-trained, well-coached athlete using the best equipment and with much experience in any sport. It doesnt mean the amateur has no potential. If it did, we wouldn't have sports because there would be no development of new talent.

The DWing has done okay a couple times, but I don't think any honest person would say it has reached its full potential, yet we are comparing it to cars with years of development which have reached full potential.

Basically, if you like the DWing you want to see it develop, and if you don't like the DWing, you don't.

You don't like the car, but all your numbers don't prove anything except that you will spend a lot of time telling people you don't like the car.

That's fine; chacon a son gout. But you cannot prove that your dislike is more rational than my affection for the car, no matter how many equations you post.

[HJJ]

Originally Posted by Canada ALMS fan

How many will actually race next year? I assume Dr. Panoz will run the current one with Dave Price. Will anyone else? We haven't heard of any potential sales.

Yes, there are people interested in purchasing the Deltawing. Because of Monday's Continental tire test after Petit, a test session with perspective owners and drivers had to be postponed. The team is just getting back to work after a well deserved week off and this should happen in the near future.

[HJJ]

Originally Posted by Machin

This suggests that there were no P1's or P2's running in the test? Can you confirm that?

Yes everything in John's article is correct.

[deltawing]

Originally Posted by Machin

That's an interesting comment... bearing in mind that all the deltawing numbers I have quoted come directly from the two teams that designed and ran the car, so are you suggesting that they have lied about the specification/aerodynamic performance of the car and they are in fact not achieving the figures they are claiming, be that the mass, power or aerodynamic numbers? This would be very disappointing since most of the excitement surrounding this car was based on the numbers that the designer/team were claiming they were going to achieve.

(My personal view is that the mass/power/aero numbers are right and the car is underperforming due to the "innovative" wheel layout.)

I am not suggesting they lied. I am suggesting that no one actually knows exactly what we are dealing with.

Numbers are interesting way of comparing things in life, but in this case I think just numbers can not cut it. One source said a number and it is say 1.000, then another source for another similar car said another number, say 900. Truth is, we can't just pick the two numbers, even if they are absolutely accurate for a very specific scenario, and compare the cars' performance.

As you probably well know, a race car makes very different aero numbers at each specific setup. Most times a car can achieve a fantastic peak number of DF in a specific ride height configuration, but in reality such setup is very difficult to drive because it is very inconsistent and unpredictable when it comes to dynamic setup change (i.e. the car dives, rolls, pitches, etc). So teams/drivers chose to set the car in ways that perhaps there is a smaller peak DF number, but the delta of that number varies very little and in a very predictable way when going around a track. So, you can have a car that has claimed 900 number (the hypothetical number from above) but that in reality has much better drivign characteristics (aero-wise) than the same car with claimed peak number of 1.000.

The thing is, in my view, that no one actually knows really what is going on with the DW in terms of aero performance. Yes, everybody thinks and says how this is "old news" and how nothing new was really invented because many years ago someone else did something similar and so on, but what I am saying is that no one knows exactly how to add 500 lb. of DF on that car. And it is because this is not an actual ground effect like for someone reason most believe. If you look at the footage or photos, the side tunnels are actually quite far from the ground! And I think this is partially why this car does not perform too well lately - because the way it works could be altered dramatically with just small changes, even things like altering the ride height in the wrong place by incredibly small amount.

We are also focusing a lot on saying how the coupe has 8-9% drag improvement, but also loses 8-9% of DF (reported somewhere numbers I read). But I bet there is A LOT more than just that when you close a cockpit. They must be shifting the pressure points a lot. They must be getting a very different yaw characteristics and I am pretty sure the DF distribution is altered as well. If the car responds very well to having Gurney flaps (I see that is permanent feature on all models, therefore it must be working well) this means the "over the car" vs. "under the car" flow will be altered quite a lot if you change the car in such dramatic way as closing the cockpit. We don't know if such change then brings another cascade of changes, but just for kicks let's assume the new 2.0L engine and its twin turbo setup is heavier than the old engine. Then let's assume the coupe is actually lighter than the cabrio (which I am convinced is true) - now we have a severe change in weight distribution on a car that would be very sensitive to weight distribution. Throw on top of that the new closed cockpit, which means altered pressure distribution, and you have a car that: it is lighter, it makes better numbers in each category (power, drag, etc) and yet it would be worse around a track because it has been dis-balanced from the original concept.

Don't you find it very interesting how every time it is wet, the DW (whether a coupe or cabrio) suddenly turns great lap times in comparison with the rest of the cars? ....

[miatanut]

Originally Posted by Machin

Since Power is kilowatts and that is Kilojoules/second, and fuel is Kilojoules/kilogram, we can roughly approximate a car's power (multiplied by the % of time spent at full throttle) to it's fuel consumption. I.e. a car with 500bhp and spending 80% of a lap at full throttle will roughly approximate to twice the fuel consumption of a car which has 250bhp and also spends 80% of its time at full throttle, assuming both achieve the same lap time.

An LMP2 has ~450bhp, and the Deltawing has 350bhp, and it can't achieve the same lap time. So you have to guess it is using about 77% of the fuel of an LMP2 to not achieve the same time. Even at Le Mans, where the long straights help it, it still had 300bhp (66% of the LMP2 power).

At Le Mans, the Nissan flavor of the DW was doing P2 times with 66% of the power.

Also, if you will recall, the car was making significant improvements from session to session, and made a far greater leap from the testing day to race week than any other car.

It was a new and unfamiliar beast, but they had the mind that came up with it guiding the team on what the car wants from a setup. The Panoz effort has a bunch of people who have been working with rectangular race cars all their lives without the guy who came up with the concept leading them, and I think that is part of the struggle.

Mostly, it just needs a lot more development.

[Machin]

I'm sorry if I dwell on the numbers, but I'm an Engineer and numbers mean EVERYTHING, but you are right; they have to be the right numbers and they have to be relevant to the scenario we are talking about.

But as I've said before; the numbers are interesting in this case because they are directly quoted from the team. So we have the original performance claims from when this was just a paper exercise, We have the weight and aero figures claimed by the designer/teams, and then we have the actual performance they have achieved., and they don't add up.

Yes, its undeveloped, but it was built without the restrictive rules the other cars play to. The designer said they WOULD build a car that would have the same performance for half the fuel consumption. He didn't say they'd design a car that had 75% of the fuel consumption and less performance, and neither did he say they would achieve their claim after 5 years of development.

The thing is the Deltawing is fascinating to me, because it demonstrates exactly why a car designed for corners has the tyres widely spaced and the mass equally spaced between those wheels; something that can easily be explained using numbers and some basic engineering. Some more basic engineering and numbers explain why a car with a very rearward weight distribution would be quicker in the wet (better traction), why a car which is allowed to use ground effects tunnels will have more downforce for the same drag (or the same downforce for less drag), and why a car with half the power should be able to compete with a car with twice the power if it has half the mass.

The Deltawing has done one thing very well, marketing; I have never watched the ALMS before, and it is only because of this one car that I have watched it this year.

It has been suggested that Nissan wouldn't have chosen the Delta layout for their ZEOD if they didn't see potential in it, but remember, they're not going to Le Mans next year to compete on equal grounds with anyone; they are there to demonstrate their hybrid technology. So why did Nissan choose the delta layout? I'll end on a quote from Nissan Boss;

Originally Posted by Andy Palmer,Nissan Boss

What is absolutely clear is that that...... we have to have a car that is as visually arresting as the DeltaWing.

I.e. they wanted a car that was visually different as it helps their marketing department.

[Maelochs]

"The designer said they WOULD build a car that would have the same performance for half the fuel consumption. He didn't say they'd design a car that had 75% of the fuel consumption and less performance, and neither did he say they would achieve their claim after 5 years of development."

So do All engineers regularly take advertising as fact?

I am no engineer, but to me the relevant facts are provided on the track. The car did well at Le Mans and was getting better before being punted. It did well in its next outing at Petit.

How many race cars can you name which finished fifth overall after only two races? (Ecept for F1 obviously as they have new cars each year.) How many can you name which needed No development?

It seems you are so bent on "proving" the DWing is wrong, you use a mixture of hype and supposition and then claim "Numbers are everything."

I'd bet you wouldn't have gotten an engineering degree using data which was half ad copy and half imaginary, eh?

And waht part of the car needing development is based on numbers? Because you pretty clearly state that because the car needs development it's a failure, and that equation really doesn't add up in the real world at all.

I am not saying the DWing is "The Future of Motorsports." In fact, I have made a lot better arguments against the car than you have here. What I am saying it is an interesting new concept which started to prove itself and then got handed off to a team which hasn't been able to make it work.

The ZEOD is where we will have to look for developments of the concept, because that is where Ben Bowlby is. I don't think the Elan crew is going to improve on the original. So let's see what the ZEOD can do.

And lets stop trying to "prove" something using imaginary numbers. Unless you are in touch with the team and have verieifeied hard figures, you are using promotional material, which is great if it helps you make a case, but that case is false if those numbers aren't current and accurate, and since you have no way of knowing ....

The horse jelly is approaching.

[Machin]

I think you missed my point about the significance of the origin of the numbers:-

I am not saying the numbers are right or wrong (I don't know), I'm saying that the numbers originated from the team/designer.

My point was that the numbers the team are telling us either contradict the performance we're seeing or they contradict the designer's insistence that the Delta-wheel layout wouldn't affect cornering performance. Either way the team/designer appears to have claimed something that they, as yet, haven't been able to back up with the performance on track.

Yeah, the car has done OK for itself (i.e. it managed an OK performance with less power/fuel consumption) but this is nothing less than we should expect it to do in accordance with Newton's second law (see posts above) considering that it has been built without adherence to the minimum weight rules, and in accordance with the fact that it has been designed without adherence to the underfloor aerodynamic rules that the normal cars are built to.

Look at it another way: you've been given the opportunity to build a one-off car and you can ignore all the strict rules the current cars are hindered by. You'd hope that a fairly competent engineer would be able to incorporate ground effects tunnels onto the car without doing anything detrimental to the performance right? So if you took a current LMP2 and put underfloor tunnels on it you'd expect it to be faster than the LMP2 you started with, right? That would place it above the curve in those charts I've posted above. You'd then build the car in a way so as to achieve the lightest weight possible: we know an LMP2 can be built to 675kg without too much difficulty because that's how they used to be made. That's 75% of the weight of the current car. We'd then give it the same 350bhp the current Deltawing has (that's about 77% of an LMP2's current power), so that the fuel consumption is comparable. We've now increased the power: weight (very slightly) so we'd expect the car's performance to be (very slightly), higher up the chart.

So that's why I'm disappointed: given free-reign to ignore the strict rules, you'd expect any new car to be faster (it is, afterall a technology demonstrator) than the car's that are built in accordance with those rules. The Deltawing, despite the free-reign, has failed to achieve that.

In the category of racing I am involved with (Speed Hillclimbing in the UK), there are very few rules. When a new car comes out it is quite normal for it to be one of the fastest cars because it will incorporate all the best features of the current cars plus the latest innovative features; and that is when competing against other cars that are also built with very loose rules, not against cars that have very strict rules (as in the case of the Deltawing's opponents).

So that's why I'm disappointed in what we've seen so far..... it seems like a bit of a wasted opportunity to really prove what is possible if you ignore the rules....

...But like you say, we'll now just have to wait until the ZEOD starts running before we can move the discussion on further.....

[deltawing]

Originally Posted by Machin

.... You'd hope that a fairly competent engineer would be able to incorporate ground effects tunnels onto the car without doing anything detrimental to the performance right? .....

The DW does not have ground effect tunnels. The car does not work by using ground effect. On a real ground effect car, you get the max performance by sealing the side skirts with the floor. If you do this on the DW, the car will lose its DF completely. If you look at the pictures, the "side skirt" on the DW is actually designed in a way that increases the gap to the floor as it propagates rearwards.

[optica]

Originally Posted by Machin

It has been suggested that Nissan wouldn't have chosen the Delta layout for their ZEOD if they didn't see potential in it, but remember, they're not going to Le Mans next year to compete on equal grounds with anyone; they are there to demonstrate their hybrid technology. So why did Nissan choose the delta layout? I'll end on a quote from Nissan Boss;



I.e. they wanted a car that was visually different as it helps their marketing department.

Though they might not be competing directly for any class honours they still have to produce a vehicle that will achieve the performance & lap times they are claiming is possible. If they don't get the results they are after it will be a PR disaster so they need to be pretty sure they know what they are doing. Why would they take a chance just for the sake of having a vehicle that is "visually different"?
There was plenty of evidence last year that the DW was beginning to reveal the true potential that was inherent in the design. The fact that the Panoz effort has lost its way is a shame. Just as they appeared to get the open car somewhere near the performance it was managing at last year's Petit Le Mans they go back to square one with the coupe....and now its the coupe with yet another tyre supplier. Michelin already know where they are to a great extent with the Zeod.

[Machin]

Originally Posted by deltawing

The DW does not have ground effect tunnels. The car does not work by using ground effect. On a real ground effect car, you get the max performance by sealing the side skirts with the floor. If you do this on the DW, the car will lose its DF completely. If you look at the pictures, the "side skirt" on the DW is actually designed in a way that increases the gap to the floor as it propagates rearwards.

Whether it be "Ground-Effect" or the so-called "Boundary Layer Adhesion Technology (BLAT)", the fact remains that the car does not adhere to the strict underbody rules of the rest of the grid. Less restriction = more performance, surely?

Anyway, with the Deltawing's racing career over for the year we cannot come to any further conclusions as to why it performs as it does, so we're just covering old ground.

[TME45]

Nissan has lunch Street version of DW/ Zeod RC concept car @_@

http://photos.nissan-global.com/EN/1...x.html#content

[bjohnsonsmith]

Originally Posted by Machin

Whether it be "Ground-Effect" or the so-called "Boundary Layer Adhesion Technology (BLAT)", the fact remains that the car does not adhere to the strict underbody rules of the rest of the grid. Less restriction = more performance, surely?

Anyway, with the Deltawing's racing career over for the year we cannot come to any further conclusions as to why it performs as it does, so we're just covering old ground.

The DW was never meant to adhere to the strict underbody rules of the rest of the grid, hence Garage 56. Remember the the DW was originally conceived as a replacement to the ageing Dallara IR5 IndyCar.

[TME45]

Originally Posted by bjohnsonsmith

The DW was never meant to adhere to the strict underbody rules of the rest of the grid, hence Garage 56. Remember the the DW was originally conceived as a replacement to the ageing Dallara IR5 IndyCar.

DW get Diffuser but dosen't mean it is ground effect car
it just same size as normal LMP1

[HJJ]

Will be at the Sebring and Daytona test.

[MulsanneMike]

Originally Posted by TME45

DW get Diffuser but dosen't mean it is ground effect car
it just same size as normal LMP1

Whhhaaaaat? The DW has tunnels and they work in conjunction with the air flowing under the car and through those tunnels, i.e., what is commonly known as ground effect. Any race car that has an underfloor (whether flat-bottmed, tunneled, spec, or whatever) that is designed to interact with the flow underneath the car in order to enhance downforce is considered a "Ground Effects" car.

And what's a "real" ground effects car anyway? What deltawing is talking about hasn't existed in 30 years (sliding skirts). Sliding skirts were banned years ago and the motorsports community moved on without them, successfully developing the ground effects concept further (US open wheel cars, IMSA GTP, Group C).

BTW DW has large vortex generator ahead of the leading edge of the tunnels (yes, those are tunnels in that the leading edge height is lower than the trailing edge height):





In concept these aren't very much different from what we ran in CART or IRL, except justify the whole setup rearwards.





BTW, "BLAT" is a ****-take on the term "ground effects" :

If you’ve (got a) racing car you want it to be pulled down on the ground to give the tires more traction. So, we came up with a term called the ‘BLAT’ effect. You see, we’re not using ‘ground effects,’ we’re using ‘BLAT.’” “Well wait a minute, what do you mean ‘BLAT?’” “Boundary Layer Adhesion Technology.” “It was supposed to be funny (at that the audience laughed loudly).” “Anyway, all these other old-fashioned guys were working with ‘ground effects’ and, of course, we had ‘BLAT.’”

Source: http://www.automatters.net/2004%20Columns/0114.htm

[TME45]

Originally Posted by MulsanneMike

Whhhaaaaat? The DW has tunnels and they work in conjunction with the air flowing under the car and through those tunnels, i.e., what is commonly known as ground effect. Any race car that has an underfloor (whether flat-bottmed, tunneled, spec, or whatever) that is designed to interact with the flow underneath the car in order to enhance downforce is considered a "Ground Effects" car.

And what's a "real" ground effects car anyway? What deltawing is talking about hasn't existed in 30 years (sliding skirts). Sliding skirts were banned years ago and the motorsports community moved on without them, successfully developing the ground effects concept further (US open wheel cars, IMSA GTP, Group C).

BTW DW has large vortex generator ahead of the leading edge of the tunnels (yes, those are tunnels in that the leading edge height is lower than the trailing edge height):





In concept these aren't very much different from what we ran in CART or IRL, except justify the whole setup rearwards.





BTW, "BLAT" is a ****-take on the term "ground effects" :

If you’ve (got a) racing car you want it to be pulled down on the ground to give the tires more traction. So, we came up with a term called the ‘BLAT’ effect. You see, we’re not using ‘ground effects,’ we’re using ‘BLAT.’” “Well wait a minute, what do you mean ‘BLAT?’” “Boundary Layer Adhesion Technology.” “It was supposed to be funny (at that the audience laughed loudly).” “Anyway, all these other old-fashioned guys were working with ‘ground effects’ and, of course, we had ‘BLAT.’”

Source: http://www.automatters.net/2004%20Columns/0114.htm

sorry for my bad explain
what I want to ask is some ppl said DW get huge advantage under floor, if he can make a car same as it with tradition shape, it can faster then DW. But the true is DW's under body advantage is just same as normal LMP

[MulsanneMike]

Originally Posted by TME45

sorry for my bad explain
what I want to ask is some ppl said DW get huge advantage under floor, if he can make a car same as it with tradition shape, it can faster then DW. But the true is DW's under body advantage is just same as normal LMP

I disagree. DW's primary aero advantage comes from the very efficient production of downforce via the non-regulated underfloor design.

[TME45]

Originally Posted by MulsanneMike

I disagree. DW's primary aero advantage comes from the very efficient production of downforce via the non-regulated underfloor design.

but what we see on the floor, there are no huge advantage on DW.

the most advantage of DW is the loading(included weight & downforce)/ tire surface ratio is same as normal car, & the tires won't stress themselves during cornering

[Maelochs]

The fact that the DW gets sufficient downforce without wings leads me to believe that its underbody makes the difference. Otherwise, where is all the downforce coming from?

As for whether it is more or less underbody downforce than any other LMP1 ... I guess we'd have to take the wing off another P1 to test that.

Pretty clear that the DW underbody develops more downforce proportional top vehicle weight and proportional to lift than any other P1 car, eh? Otherwise, how does it stick without wings?

Even not knowing absolute numbers (lbs. of underbody downforce for DW and any other P1) common sense says the wingless car gets it from somewhere else, and where else would that be?

[EricS]

Does no one remember the article from Mike when the DW first came out? Or has this been disproven?

http://www.mulsannescorner.com/newsmarch12.html

The underfloor leading edge treatment is designed to shed a large vortice into the underbody, the DeltaWing guys call it, "Twin vortex underbody downforce system – BLAT (Boundary Layer Adhesion Technology)," a ****-take on the term "ground-effects" (see the link). Whatever it's called, this vortex generator is how the concept develops all of its approximately 2500 lbs. of downforce.

[CyberMotor]

Originally Posted by EricS

Does no one remember the article from Mike when the DW first came out? Or has this been disproven?

http://www.mulsannescorner.com/newsmarch12.html

Interesting statement here from Mike, "DeltaWing's greatest impact might simply be the stimulation of thinking about the future of the car, sportscar racing, and motorsports in general. But perhaps the starting point is, does motorsport have to really have to be relevant?"

While this question may have not been answered in some fans minds, I think the major manufacturers in racing have already answered this with a "Yes" in most cases. Obviously, Audi, Toyota, Porsche, Nissan and now Ford have responded with their answers and it is a 'Yes'. If the teams are attempting to justify the tremendous expenses to the Board of Directors, then attempting to explain that the expenses are just for fun and entertainment of a small crowd doesn't get you too far.