aerohead -
Quote:
Originally Posted by aerohead
Maybe every vehicle should be considered on a case by case basis.
The car shown is a rally car.Past Ford rally cars suffered higher drag as a compromise to cornering downforce from induced-lift.
Front airdams,as reported in industry literature typically reduce drag on non-bellypan cars,then at some point,begin to increase drag as their frontal area grows beyond some point. Bondo found this to be true on his F-150.
Some writers discourage the use of "rules-of-thumb" and advocate that every vehicle be investigated on a case by case basis.
It IS MY OPINION the the airdam pictured WOULD increase drag and degrade mpg.JMO.
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Yup. I was reading about the
Opel Calibra, a car famous (among us) in the early '90's for having a Cd of 0.26 . When they were designing the front air dam, they came across this very issue. They found that if it was too low, the drag from the air dam overcame it's benefits. It's job is to get the air past all the messy engine and front suspension components. Once it has done that, it doesn't need to be any bigger. If we did a detailed analysis of the Opel Calibra, we would probably be able to come up with a simple rule-of-thumb equation.
I read this in
Car Styling issue #192, which has a continuing series on car aerodynamics :
CarloSW2