Question? Highest speed recorded in a race

[Anthony]

I believe D. Smith went 198.

I remember reading an article about it. Dick just didn't drive his car out on the track, with the same set-up he used for road racing. He knew the car got light at speed, and therefore he lowered the front several inches to give it some rake. He said it still was squirrelly, and he would never drive it that fast again. He also changed the rear gears to 3.07's or 3.23's, or something such that that he topped out at about 7000 rpm's. There were a couple other things he did, but I can't remember them from the article though.


Cal,

friction, or air resistance increases with the square of the speed, so it requires 4 times, not 8 times, the hp to drive the car at 100 mph as compared to 50 mph. The formula holds true with engine rotation and tranny friction with respect to rpm.

Someone talked about weight of the cobra. It is not a factor at a constant speed (top speed). Whether the cobra weighed 1500 lbs or 3000 lbs would not matter, assuming cornering is not limited. However, acceleration, yes, weight makes a difference.

Coefficient of drag , Cd, is a relative number. It really means nothing by itself, only on the relative flow efficiency of a shape in a moving fluid. (car body in air) (submarine in water), etc. To determine the resistance to flow, you take the Cd and multiply it by several factors, one of them the frontal area of the object (car). A boeing 747 probably has a much lower Cd than a jeep, but the overal air resistance at 200 mph is likely higher with the 747 because the cross sectional area is so much greater than a jeep, even though the 747 has with a lower Cd advantage.

If you want to know how to calcualte friction in a moving fluid, I can look it up in one of my engineering books to get all the variables. Some of them are : Cd, cross sectional area, viscosity of fluid, fluid speed, there may be others, but I can't think of them right now.