....How did you go about calculating the down force needed, or the amount of down force this wing can generate? It seems to me, that too much down force will add to drag, and also will/may add too much 'weight' to the tires....
As John stated the wing in that position would be the extreme and not likely to happen and you are right trying to calculate the downforce of a wing is beyond us. Not sure if you read the page or not but the wing isn't a wing in the more familiar sense of an airplane wing that is designed for lift or downforce if placed upside down.
Our wing is actually a helicopter blade, we don't know which helicopter, and .....
...is designed to be neutral as far as we know. So if it is parallel to the ground and in free air, not close to the ground or the body of the car, it should produce no lift in that situation. It produces lift or downforce by changing the angle of attack. If we used a normal wing shape, not neutral, then more knowledge would sure be needed. I'm hoping that we are also taking the old trunk lid with the spoiler that has been used attached just in case we think we need to revert back to it at SW.
You are also correct in that anytime you are creating downforce or have the wing and the vertical stabilizers in the air you are creating more drag. We hope to have more HP
. Also we feel that in order to have the traction to deal with the higher HP and speeds we would need more rear weight in the car which would also mean more nose weight to keep the Center of Pressure ahead of the Center of gravity. The car weighs 6000 now to do that or close to it. More weight would hurt acceleration that is also needed at higher speeds. The wing if it works will help a lot with the Center of Pressure and with putting more force on the drive tires. So it might offset the drag penalty, but the key is we still need more HP than we have had to go faster than the 253 the car has run.
On our low speed runs working up in speed we will start with it very slightly up hoping to produce a small amount of downforce at first and try to stay away from any lift. We had hope to find a smaller helicopter blade, but have had no luck there. Some blades have to be replaced after so many hours and others can be reconditioned/re-certified as we understand it.
Mark made an inclinometer to use in adjusting it, pictures later when I get it. He also made some rods with rubber o-rings on them that we hope to mount on the car on all 4 corners that will give us a record of how far the suspension is compressed or if it lifts. Knowing spring rates and using these might give us some crude downforce data.
Hooley also wants to change the front of the car to a straight axle for 2014,
Sum