What? Aerodynamic drag is a force, by definition. It is not a moment (aka torque) which is what your units imply.

 

I know Vjay from the BMW group. He is a fairly new pro racer, and was ok in the club ranks. when he got a REAL hot car, he started to dominate. anyway, its safe to say that the lap times of that car, are equal to any good driver running without a wing at all!! in fact, i for one can tell you that just putting a wing on a car does nothing, unless you match the front end with a splitter. sometimes you dont gain a thing, as i didnt when i put on my wing. however, it did make those fast laps a little easier, and safer to run fast through traffic and off line. I also think that putting down force on the opposite corner of the rear turn is contraproductiive to gaining grip, not to mention you reduce the downforce to 1/2 when the steering wheel turns. Then, think about the full wing angle off attack on straight braking. its nice to have 20lbs of drag trying to stop you, but quite frankly, the "wheelie effect" takes grip away from the front where you need it to take advantage of the 1000hp of braking forces!

Its cool to watch, but I would feel no fear seeing any of my competitors use this.

those lap times are just about the spread we all see going from practice to the race. .5 to 1 second a lap improvement with no changes!

mk

 

???????

am i the only one that thinks this guy doesn't know what he is talking about

"a rear wing does nothing unless you match the front end with a splitter."
so in order for a rear wing to do something, you need a front splitter?

 

omg

 

x double

 

From the way you talk of him it seems like you aren't very close to him - how credible can your evaluations of VJay possibly be? If he is an upcoming pro racer and was ok in the club ranks, that's wonderful - he is obviously improving. If you say he is dominating because of the car he is in.. i think that has alot to do with your jealously in VJay.

 

Just to answer some questions form my own research into similiar concepts:

Q: Why would you want an active system?
A: To create the least amount of drag when you you don't need the downforce (straightaways) and the maximum amount of downforce when you don't care about drag (braking and corner entry). A wing is always a trade-off between drag and downforce. A static wing forces you to pick one compromise position for the entire lap. A dynamic wing let's you change this compromise to the optimal solution for every point on the track.

Q: Why would you want more downforce on one side than the other?
A: Given the optimal amount of downforce versus drag for a given spot on the track, you would rather have most of the force on the inside of car in an attempt to balance the car. With the same amount of force, you will achieve higher total grip due to the tire's non-linear relationship between normal force and grip.

With a magical wing, this means you would always want the inside element at a higher angle of attack than the outside to produce more downforce. In reality though, wings stall and lose their ability to produce downforce after a certain AoA dependent upon the airfoil and the conditions. Therefore in practice, for an optimized system, I imagine you'd see both elements pegged right before their stall angle through most of the corner, where the need for downforce dominates any drag that might be produced. The differentiating would happen towards corner exit when the drag starts to matter more than the downforce. A larger wing would shift this point earlier in the corner, but now your in another trade off between downforce, weight, and drag even with no AoA.

Q: What good is a rear wing by itself?
A: A lot. Not nearly as much as a combined front and rear system, but there seem to be some misconceptions about "balance." More is almost always better. If you have "too much" rear downforce, and therefore too much rear grip, then you can adjust your car to a front grip (oversteer) bias. The downforce will then compensate for this at speed and you'll achieve higher overall grip. Additionally, a dynamic rear wing can be used as a speed brake. It can be adjusted straight up for the maximum amount of drag. This makes a significant difference in aero deceleration alone; even if the car was not touching the ground it would slow down quickly at high speeds. Without the coordination of a similiar effect in the front, you can still running bigger brakes (or higher bias) in the rear, leading to greater overall mechanical deceleration too.

The only possible determent is if system is creating such a great force so far behind the wheels that it acts as a lever acting on the rear axle. This can take force off of the front axle. While this force is transfered to the rear, we again consider the non-linear property of the tire and realize we are losing overall grip. If this happens, the system is poorly designed. Either the load path needs to be moved closer to the fulcrum or less downforce should be run.


I'm not trying to say that Aeromotions has implemented this 100% correctly, but that is the theory. If anyone has more questions or disagrees and would like to discuss a point further, then let's hear it!

 

That doesn't account for the fact that downforce is variable with speed. If you adjust your car for optimal balance at 80 mph, it'll be way too loose at 40 mph. If you adjust your car for optimal balance at 40 mph, it'll be way too pushy at 80 mph.

 

Sure it does. You adjust the car to rotate at low speeds (oversteer bias) so you can get the slip angle you need to navigate the tight corners. Then, as you speed up and gain rear grip, the car becomes more stable and total cornering forces increase. At some point the downforce will be so great that the rear grip will far exceed the front grip, and you won't actually be able to use it to your advantage since the car will push at the "limit."

So what? Even if you can't use all the available rear grip because you are limited by the front grip, the overall grip level is still higher than a setup with no wing and a more understeer biased chassis. A combination of downforce in the front and rear is unquestionably better, but downforce on the rear axle is better than none at all.

 

In theory that sounds reasonable, but in practice I've found that a balanced car with slightly less grip goes around a track faster than a very pushy car with slightly more grip. I don't know the physics behind this, so maybe someone else can chime in.