Cobra and Daytona Coupe at LeMans.

[Aggressor]

A couple of videos that seem to be vintage. (Edited later -The Mulsanne straight has two chicanes in it which would make these videos 1990 or later. They're still good viewing though)

http://www.youtube.com/watch?v=mj6rZ...layer_embedded

http://www.youtube.com/watch?v=qW-bc...layer_embedded


-Geary

[Slither]

Interesting videos... I wonder how fast they were able to go. Any ideas?

[Aggressor]

Hard to say from the footage. The roadster, because of it's blunt shape, hits the aerodynamic "brick wall" at 160. The Daytona was a 200 MPH car.

A fun fact or two:

In 68 the 427 big block GT40's were hitting 240 on the Mulsanne having to lift off for a 200 MPH (maximum) bend in the straightaway. The GT40 drivers were quoted as saying they could spin the tires at over 187 mph. (again - before the 1990 speed limiting chicanes)

-Geary

[eliminator]

He's hauling the mail in the second video.......

[Jerry Cowing]

Aggressor,

The 160 mph wall is not true. Dick Smith was clocked at 198 mph during one of his races in a Cobra. Do some research and check it out. He was quite the Cobra racer.

[Aggressor]

Jerry, I'm familiar with the Dick Smith story and it seems to be documented and true. I understand the 160 wall was a statement by some of the original 60's drivers. The car's shape as we can all attest to, punches a fairly large hole in the atmosphere with much buffeting. I've not seen CD figures but the drag numbers have to be enormous. Also the body shape has to be generating hundred of pounds of lift at high speed. Daytona's steep banks could have been a factor in the 198 mph by loading the suspension to (not eliminate) but balance out the lift. I'm sure that Shelby himself spoke of "The Wall" in a video interview. I'll research it.

- Geary

Later Addition: The small blocks were considered 160 mph wall cars.

"The power of the Cobras on the short American tracks was unbeatable, another right car at the right time in the right place. But on the longer European courses, speed was the key. The Cobras had run against the GTO's early in 1963. The open roadster, small block Cobras couldn't exceed 160 mph. The closed coupe GTO's were considerably faster. A 24-year-old Shelby American employee named Pete Brock convinced Shelby he could develop a new weapon for the Shelby arsenal, a coupe. Aerodynamics were the key, Brock was convinced. He said "he was influenced by some obscure German papers written by Wunibald Kamm." Kamm wrote about air flow and how important it was not to fight the air. Brock told Shelby it would take four times the horsepower to get a roadster to go 200 mph than it would to 100 mph. It would be a lot easier to reduce the drag of the cars than to increase the horsepower that much. And the car would qualify for FIA rules under the new interpretation used by Ferrari. The coupe project started in October 1963"

The drag coefficient for 427 Cobra S/C is 0.42, frontal area is 2.26 m2 (from Road&Track 1966)
Daytona Cpe had cd = .29

Coefficient of Drag (Cd): 0.42
Frontal area (sq. ft.): 24.3176
Vehicle and Rider Weight (lbs): 2550
Speed (mph): 198

Horsepower Needed: 551.6