Quote:
Originally Posted by Peter7307
Sorry but not so.
The St Cyr wind tunnel in Paris was in use in the 1920's and is still used today especially by Citroen and Peugeot.
Coast down tests are probably still used by some makers but most have moved on the CFD and wind tunnel data.
German universities also had auto wind tunnels in the 1930's to help with the aero work on the Audi and Mercedes cars of the mid and late 1930's (usually referred to as Silver Arrows)
Peter.
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Hi Peter,
I think you misunderstood. I meant that the lift and drag numbers before 1974 were from wind tunnels that were built to study airfoils or aircraft. The only 1:1 scale automotive tunnel before the oil embargo was the GM Harrison tunnel used to test cooling system flow. Since that time really wonderful study centers have sprung up all over.
But in particular, the Saint Cyr "giant" tunnel of 1920 was not an automotive type tunnel. The test object was suspended by 5 wires and the forces on the wires gave you the lift and drag. I think the nozzle exit area was about 4 or 5 sq meters. Which would be about 1:5 scale for an automobile.
I see aerohead
posted this.
The EPA uses coast down tests for drag measurements. Advertising can, of course, use any numbers they like.
-mort