Ok, I have a problem with replies to questions 4 and 5. First, I don't understand how having litle weight at the front makes the car need only a small contact patch to turn. Doesn't downforce "create" weight anyway? Doesn't less weight mean the opposite of what they reply, meaning, the need for a greater "patch" of contact with the road?
Second, and specifically about the reply to question 5, my problem is double: 1) I'm no enginier; 2) I'm not an English native speaker. So ... I just don't understand that reply properly, could anyone more knowledgeable both in engineering and in English help me out?
Q4 - Think of the car as a Porsche 911 taken to the extreme. All the weight supported by the rear wheels basically. The fronts only exist to turn the car (and for braking I guess).
Downforce does add weight, but you can control the the balance between front and rear just like with gravitational weight. The difference between downforce and gravity though is mass. Adding weight through gravity means you add mass, which means you need to apply more force to get a given acceleration. Example, you have a 2000 lb car. When you turn the car, the front wheels produce 2x lbs of force. The lateral acceleration is propotional to 2x/2000. If you add a 2000 lb ballst to the car, the front wheels produce 4x lbs of force. In the turn, you get an acceleration of 4x/4000, which is the same as 2x/2000 and it behaves the same
*. If instead you add 2000 lbs of downforce, the acceleration in the turn looks like this: 4x/2000, which is double the acceleration in the other cases.
*Non linear tire performance keeps this from happening in real life.
Q5 - Torque from the force generated by the front wheels is what turns the car. Torque = force * moment arm. Moment arm is a distance, and this is the lever talked about in the answer. Placing the cg back makes the distance between the cg and front wheels longer, allowing a smaller force to create the same torque as a larger force with a smaller moment arm.
The slow sections are where aerodynamics have no effect and it's all about mechanical grip so doesn't really effect it not having wings. It's supposed a ground effects car. I don't know much about ground effects hence why I'm skeptical but that would explain the early f1 cars having little wings. Delta wing is such a great mystery. Ill have to see it to believe otherwise lol.
Slow is a relative term. Aerodynamic devices can provide useable downforce at any speed depending on the car. Ground effect is good in that it produce wing level downforce without the drag, but it's sensitive to ground clearance and suspension travel. It probably also has a lot less tolerance for positive angle of attack, where it could easy create lift instead of downforce.
To illustrate these disadvantages I have modelled a rectangular ground effects car which I humbly call the “Machin Wingcar”:-
I really like this guy's design. I think it could be more of a threat to the Delta than current LMP's, though I wouldn't discount current LMP's against the car either. We would probably see LMP's more like the car that this guy proposed if rules were loosened.