Delta Wing Discussion ONLY

[TME45]

Originally Posted by Mt. Lynx

Q:
Take an LMP2 car - say the Lola B12/80 Coupé - strip off all of its wings, and give it groundeffect instead. How much more efficient would it get in terms of fuel, drag and tyrewear?

it will fly away, and the drag is still higher, because the LMP shape is always like a wing to produced lift force.

[wnut]

Originally Posted by Pandamasque

Let me clarify my position once and for all. I don't really hate the vehicle that DW is. I generally dislike bull***, that's why it seems that way. When something becomes good only because it's beaten into your head by some good PR-people, it becomes even worse in my book. I hope I won't see it next year, but it may become the car to have in ALMS 2013.

There is every reason to think that this car is vastly inferior in every respect to a hypothetical rectangular car designed and built by the same people with the same resources, even using some of the same concepts!
Ask yourselves did you REALLY need a wacky-looking vehicle to prove you that the current LMP rules severely restrict efficiency?! This is an extreme example of thinking outside the box for the sake of thinking outside the box. And I have absolutely no problem with any kind of fun quirky nonsense, as long as it's not being 'spinned' as the breakthrough in technology that seems to have already overshadowed everything else that will happen in sportscar racing this year.

PS: @canam
I'd rather see a semi-works Nissan LMP1 effort fighting with the Lolas and HPDs.

Good post!

[joeb]

Originally Posted by Adam43

They've done that for every other class! They call this approach "the rules"!

Point taken!

[TME45]

we should rember that the engine now is "only" 300hp, even a home make Turbo AE86 could do it easily. no need to talk about it is a hi-tec 1.6T direct infection race car engine. it is no problem to get 350-400hp if they want.

[wnut]

Originally Posted by TME45

it will fly away, and the drag is still higher, because the LMP shape is always like a wing to produced lift force.

www.youtube.com/watch?v=9mQogU2ibwA

Above is a link to a presentation by Tony Southgate on the Jaguar XJR9's
rear aerodynamics. The concept would work just as well if the rear wing was incorporated in the bodywork to form a longer venturi tunnel.

The Delta just has a set of narrow front wheels which cause turbulence and ruins the downforce generating airflow under the car. It also has far shorter tunnels beneath the car and a smaller area to exploit the negative pressure generated in the ground effect which makes it monstrously less efficient than a conventionally configured car!
The only way to test the concept is to run it, as has been suggested above against conventionally configured cars built to the same set of rules. That is what racing is about! (Mercy please James )

[MulsanneMike]

Originally Posted by wnut

www.youtube.com/watch?v=9mQogU2ibwA

Above is a link to a presentation by Tony Southgate on the Jaguar XJR9's
rear aerodynamics. The concept would work just as well if the rear wing was incorporated in the bodywork to form a longer venturi tunnel.

The Delta just has a set of narrow front wheels which cause turbulence and ruins the downforce generating airflow under the car. It also has far shorter tunnels beneath the car and a smaller area to exploit the negative pressure generated in the ground effect which makes it monstrously less efficient than a conventionally configured car!
The only way to test the concept is to run it, as has been suggested above against conventionally configured cars built to the same set of rules. That is what racing is about! (Mercy please James )

For what it's worth, DW's L/D is around 5:1. That puts it ball park to Audi, Toyota, etc.

[miatanut]

Originally Posted by MulsanneMike

For what it's worth, DW's L/D is around 5:1. That puts it ball park to Audi, Toyota, etc.

Well this is interesting!

Underwings are normally more efficient, and this thing is all underwing but it's not getting much gain from it.

On the other hand, the rectangular cars are all highly refined and this idea is a relative infant.

Given it's a low-drag design, if L/D is about the same, that also means it's relatively low downforce, which given the low tire wear (indicating to me a relatively hard compound) means overall it is a pretty nice trick. I thought it had gobs of downforce to work with.

[wnut]

Originally Posted by MulsanneMike

For what it's worth, DW's L/D is around 5:1. That puts it ball park to Audi, Toyota, etc.

...and Audi and Toyota are running much more massive tyres, necessitated by their weight penalty, inefficient wings (compared to ground effect tunnels), and greatly restricted ground effects.

How can the unregulated Delta be claimed to be an efficient design if it is no better than a conventional car, that is massively compromised by restrictive rules?

[MulsanneMike]

Originally Posted by miatanut

Well this is interesting!

Underwings are normally more efficient, and this thing is all underwing but it's not getting much gain from it.

On the other hand, the rectangular cars are all highly refined and this idea is a relative infant.

Given it's a low-drag design, if L/D is about the same, that also means it's relatively low downforce, which given the low tire wear (indicating to me a relatively hard compound) means overall it is a pretty nice trick. I thought it had gobs of downforce to work with.

Well they are typically yes. But DW's underwing is particularly short and the overall plan area is much reduced compared to the standard 2.0 m wide by 4.65 m long underfloor area of the current LMPs. Yes, it's giving up about 2000 lbs DF. Figure 5:1, about 500-600 lbs drag = 2500-3000 lbs DF and the top LMPs are estimated to be around 5000 lbs+.

[MulsanneMike]

Originally Posted by wnut

...and Audi and Toyota are running much more massive tyres, necessitated by their weight penalty, inefficient wings (compared to ground effect tunnels), and greatly restricted ground effects.

How can the unregulated Delta be claimed to be an efficient design if it is no better than a conventional car, that is massively compromised by restrictive rules?

In this case efficiency is measured in low drag. With 500-600 lbs drag it has between 400-500 lbs less drag than an LMP1. And remember, it's been heavily boxed in by the ACO. So while yes, it was effectively written without any rule book, the ACO has said don't go faster than XYZ. So I'm sure they've checked them selves and it isn't as efficient as it could be. Anecdotally we know it isn't if only looking at the time plan for development. I'm sure they'd loved to have had a few more months in the tunnel. Point being: it could be much better.

[parts]

Came here on a google search..found Intelligent Life..!
Great discussion..
I think Garage 56 concept is great..and Delta Wing is a terrific way to start the concept for new ideas. Racing needs it. Diesels lapping the poor petrol cars..
Old

So..next year ..
The concept is open..


Who knows how the manufactures respond ? Or does this really open "garage" types with less funding. Still takes some $$..but I hope DW does some good times gets some distance and next year who knows what we see..

[TME45]

many people said 口 car get more area space in the tunnle under the car, so it should get more down force, however, don't forget that you also get more area on the up side of the car, it means you are making lift force. and the under side of front is so flat & big, if there are some turbulent flow go under the car, it will easy to fly away like CLR & GT1.

yes, DW's under body tunnel is smaller, it make less down force, but is also decrease lift force, relatively, the down force was increased, and the drag was decrease.

[parts]

An interesting thing in the race to me will be how the Delta reacts or allows drafting..
With the smaller frontal area and the spill off because of the triangulation will this make it less advantageous to draft..?
Because of the shape what disruption will the lack of wings cause to a car following..getting a draft..?
I don't mean in terms of safety..just in terms of overtaking..

[miatanut]

Originally Posted by parts

An interesting thing in the race to me will be how the Delta reacts or allows drafting..
With the smaller frontal area and the spill off because of the triangulation will this make it less advantageous to draft..?
Because of the shape what disruption will the lack of wings cause to a car following..getting a draft..?
I don't mean in terms of safety..just in terms of overtaking..

On Radio Le Mans, Marino said it was less effected by the car in front. Presumably it will offer less of a tow for the following car and the car behind could follow closer because of less turbulent air.

We'll see. That will be interesting.

[joeb]

Originally Posted by parts

An interesting thing in the race to me will be how the Delta reacts or allows drafting..
With the smaller frontal area and the spill off because of the triangulation will this make it less advantageous to draft..?
Because of the shape what disruption will the lack of wings cause to a car following..getting a draft..?
I don't mean in terms of safety..just in terms of overtaking..

Interesting questions regarding drafting. sounds like a good question to ask one of the drivers. Possibly a forum member who is also a journalist with access to the drivers could help us out with this?

[wolfhound]

Originally Posted by Articus

Im thoroughly impressed. I think that car is alot(significantly) quicker than we got to see at the test day...The car has a higher top speed than all of the LMP2 cars...Not to mention half the weight. Put two and two together. That car is going to be a rocket. Quite frankly the DeltWing has the potential to be on the pace of the privateer P1 cars... If they are only lapping 3:35...I think the Delta wing can do a 3:35 lap time. 300km/h top end..half the weight. It has to be faster than the P2 cars right?

Marino Franchitti thinks there is more time to come as they were running old tyres and over half a tank of fuel on the test day.

http://www.autosport.com/news/report.php/id/100163

[Machin]

By virtue of the fact that the Deltawing doesn't need to comply with the flat bottom or minimum weight rules we know this thing is going to be fast in a straight line compared to an LMP2 (all numbers from the May and June issues of Racecar Engineering, except LMP2 frontal area which I have estimated):-


That's 20% more power:weight and 47% more power:drag.

I've never believed this thing can be as quick through the corners as a conventional car but we've been constantly advised by the Deltawing camp over the months that the Delta layout is better under brakes and just as good as a conventional car around the corners... if that's true and given its much higher power:weight and power:drag it should lap way faster than an LMP2....

....watching with interest (and maybe just a touch of skepticism...)

[miatanut]

The performance has been a little disappointing based on the little we think we know about its specs, but at the same time they were running really hard tires, Don Panoz made the comment they weren't going to be aggressive, including jumping over curbs, which is how the best times are set, and this car is very different from what they are used to setting up. They are still early in the learning curve on it, and the design is no doubt nowhere near as refined as the conventional cars.

In CanAm, they used to say "The last of the old beats the first of the new." This car is the first of the new.

[R4z3rw33n]

Originally Posted by miatanut

The performance has been a little disappointing based on the little we think we know about its specs, but at the same time they were running really hard tires, Don Panoz made the comment they weren't going to be aggressive, including jumping over curbs, which is how the best times are set, and this car is very different from what they are used to setting up. They are still early in the learning curve on it, and the design is no doubt nowhere near as refined as the conventional cars.

In CanAm, they used to say "The last of the old beats the first of the new." This car is the first of the new.

Except this car is the first in a string of 'different' designs - developed solely for the sake of varying from the norm (rather than improving on it).
'New', in that context, tends to imply there has been (or, will be) a progressive leap forward as a result.

You could argue (pretty reasonably) the aims of the DW, as a concept, could likely have been achieved (to a certain extent) via more conventional means of design.
It's interesting, and I wish them well. It's just not 'the messiah' - as it's being hailed.

Edit: Is there any firm estimate as to how many laps they can run on a single set of tyres?

[Pandamasque]

Originally Posted by R4z3rw33n

Edit: Is there any firm estimate as to how many laps they can run on a single set of tyres?

I'm pretty sure we won't find out until after/during thee race. If the car outlasts the tires that is.

[optica]

It seems obvious that most detractors of the DeltaWing are mainly offended by the fact it doesn't look like a conventional sports car. Love it or loathe it I think it is a real game changer. Someone has found a way to make a land speed record vehicle go round corners very effectively and that makes it very suited to the Le Mans circuit.This is a proof of concept prototype at the very beginning of its evolution, its appearance is secondary to its function. Future vehicles using the same principles might look quite different and be amazingly quick. We soon accept things if they work well and this isn't a Sinclair C5. I'm sure designers & engineers throughout the motor racing world are following its progress with great interest as its true potential is only just being revealed.

[Machin]

I don't believe all this talk that the Deltawing is driving to a specified lap time... the whole idea of this is project is to prove the light weight/low power concept, right? If they have performance to spare, surely what they would do is down-tune the engine; tell the whole world about it and then achieve the same 3:45 lap time with even less horsepower... wouldn't they?

[Maelochs]

Funny, I haven’t heard anyone (except detractors) call the DWing “The messiah,” and I haven’t heard about any housewife in Florida seeing it in a piece of toast. I’d say that myth is debunked.

The DWing is a polarizing design, a real love-it-or-hate-it kind of car (for most folks) which makes it impossible for a lot of people to evaluate it rationally.

The car ran nearly 500 miles on one set of tires at the test day. I’d say those are some hard tires, and that if the car had sticky rubber, it might be a lot faster on a lap. As an endurance racer, maybe it would be faster overall by not stopping for tires as often, who knows?

The car was designed to prove some principles, and it has. As for how fast it might be given a full development program, nobody knows—it is all hypothesis. Nobody can rationally deny that it runs among the P2 competition with very limited testing and apparently iron tires.

As Optica points out its appearance in not the issue; its ability to prove its design concepts is the whole point. I find it amusing that so many people are hung up on its shape and not its speed. I had to get over its appearance; I understand that. But ultimately racing is about going around the track and reaching the finish line ahead of the opposition. As a race fan with a little curiosity, I want to see what the new design can do.

Do I like it? Not really. So what? It works.

Miatanut raises a point I raised back when this thing was new. We cannot imagine what other designers will come up with after Bowlby has opened so many different doors with the DWing. This is indeed “the first of the new.” Maybe some designer somewhere is right now sketching a car which incorporates some of the DWing ideas and some others, or maybe is coming up with something even newer, inspired by the intellectual explorations of Ben Bowlby.

This is not a car which was designed to look weird for Halloween. This is a car which approaches the physics problems of going fast in a car from some new angles. We have no idea what this car might spark. We might be deeply in love with some car that comes out and dominates three or five years from now, only to hear its designer say, “This whole car was inspired by the Delta Wing.”

The point of historical perspective (to me) is to avoid looking stupid in the present. The folks who adamantly insisted, “The engine belongs up front, where the horse goes in a ‘horseless carriage’” can seem comical now, but in the day they looked smart to all but the open-minded. Even Enzo Ferrari scorned advances in aerodynamics and brakes.

All the people hating on the DWing because it doesn’t look like a conventional car (which it isn’t, so … duh!) are probably going to eventually see they are on the wrong side of history here. Not to say all future cars will look like the DWing (I sincerely hope not (to me the Ferrari P4 is about the pinnacle of sports car beauty, or the Porsche 910 Carrera.)) But engineering will always lead this sport into new places, and the people who reject progress end up as rejects.

[Catingaround]

Originally Posted by R4z3rw33n

Except this car is the first in a string of 'different' designs - developed solely for the sake of varying from the norm (rather than improving on it).

iirc This design came about when IndyCar was facing a potential significant drop in power with the new engines. The idea was to design a car that could run comparable times with far less power, not just a case of being different only to be different. In a way, it was designed to improve on the norm in order to keep the speeds exciting.

It's interesting that the ACO not only limited the lap time but they also limited the top speed, seemingly to force the Deltawing to perform in the corners. (?)

[Maelochs]

I think one reasion they set a prescribed performance level was to limit the car's impact on the race. Imagine if the DWing had been significantly faster than all the P2s and challenged the faster P1s (not saying it could---please note the word "imagine.")

Suddenly folks who had invested hundreds of millions year after year would have looked foolish on international TV. Of course real race fans would have realized the DWing was an experimental car not running to the same specifications, but most viewers would only have seen that funny-looking car beating everyone else.

Very bad for business if the DWing embarrassed the big-money teams, or even the stalwart privateers. By keeping the DWing back in the pack, ACO ensured the "right" teams would get TV time---certainly the DWing will too, just because it is unusual, but ACO has to run this race year after year, while the DWing might never be seen on track again.