Quote:
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.)
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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?
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