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Old 08-08-2008, 02:24 PM   #5 (permalink)
aerohead
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front/rear

Quote:
Originally Posted by RiseAbove View Post
I was thinking the other day, since the grille on cars is a aerodynamic nightmare, wouldn't cars with rear engines be better, since a front grille is not needed?
Discuss...
RiseAbove,in the phil knox aerodynamic photo albums,under Book Illustrations,second row from bottom of 1st page,is an illustration of Walter Korff's zero-drag,cooling system design.It's used in race cars,and a good model for ecomodders.---------------------------------------------------------------One thought with respect to rear engine cars,is center-of-gravity,with respect to aerodynamic center of pressure,something critical to a vehicle's directional stability.Conventional wisdom suggests that you always want the center of pressure behind the center of gravity,which yields high speed terminal oversteer.For front-engine cars,especially front-wheel-drive cars( like the Citroen as mentioned),this is especially easy to accomplish.Moving the engine to the rear can introduce terminal understeer at high speed,and as the front of the car yaws downwind,it catches even more air,increasing the yawing moment,with potentially fatal results.--------------------------------------------Modern monster mpg concept cars with rear engines, were lightweight two-strokes,which helped address the weight bias issue,and will probably never see production.Its true that the rear layout can provide an edge with respect to cooling,however,it may not necessitate moving the engine,only the cooling system as done with Ford Probe concepts,or just idealizing the front system to Korff's recommendations.
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