Quote:
Originally Posted by Frank Lee
yer over- and under-steers are ternt around.
Having had several rear-engine vehicles, I can say I like the handling dynamics of them- nice, feather-light and responsive steering, not to mention superior traction. From a strictly utilitarian standpoint, though, it is better to have the trunk in the back, both for super heavy and oversize loads. And they are more sensitive to crosswind gusts.
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I went back into my library to make sure I was using proper terminology when describing terminal understeer for rear engined,rear drive cars.I believe I chose the correct word.Forgive me while I digress.---------------------------- I the 1930s,40s,and 50s,Mercedes,Jaguar,and Bristol were plagued with crosswind stability and gust issues within their racing programs and higher speed passenger cars,as enabled by better,faster highways.------------------------------------ Kamm's K-cars were notoriously unstable in side gust conditions.It is believed that race driver Bernd Rosemeyer's death was caused by the aerodynamic instability of his Auto Union competition car,whose bodywork deformed and buckled under aerodynamic stresses,creating assymetrical induced lift which pushed it out of control----------------------------------------- In the report on the 275 mph crash of the HONDA Hawk land speed record motorcycle streamliner,it is mentioned that Bonneville racers have died in aerodynamic instability events,at velocities as low as 60-mph.------------------------------ Korff's comments concerning disregard for C.P./C.G. issues,would be analogous to shooting arrows feathers-first.--------------------------------------- My comment about casual remarks about aero-modded rear-engined cars comes from Korff's insistence that C.P. equal, follow the C.G..In a side gust condition,the apparent wind force vector will act on what Hucho refers to as the "lever arm" between CP and CG,and the front of the car can be pushed into a high speed understeer,turning the front of the car off centerline into an even larger cross-sectional area against the the air,in turn,amplifying the yawing moment with potentially fatal consequences.------------------------------- Korff considers the cars to be directionally unstable at high speed,difficult to manage,and a menace to other cars and its driver."C.P. should be at or behind C.G. for high speed stability."------------------------------------- Since,as mentioned,oversteer "freaks out" most motorists,low speed understeer is designed into basically all passenger cars.If the front breaks away,just steer in the direction you want to go,and apply more throttle.------------------------------------------- If you loose the front end at high speed your basically screwed.If you loose the rear,you can apply opposite-lock steering and judicious use of throttle to coax the front end through a curve or back into a lane.-------------------------------------- Parting remark,CP is so difficult to ascertain it requires a windtunnel to determine its location.Our ecomodder friends in Europe,with access to the Autobahn,could be tempted to test the top speed potential of their cars.Since we have no control over the weatheri it's extremely important to understand the forces we're playing with.Lives depend on it.I've done some pretty stupid things and circumstances have played out such that I'm still around.Don't flirt with disaster.If you do,do it where there are EMTs and ambulances.Saving fuel is a noble thing but its not worth your life.