OT: Friend's Article on Selling his 1977 911S
06-12-2013, 12:46 PM
#31
Rennlist Member
06-12-2013, 06:12 PM
#32
Race Car
Polar moment of inertia has nothing to do with anything discussed here. A rock in a sling does not even remotely describe vehicle dynamics. Short of wasting my time trying to explain basic vehicle dynamics, I will say this:
A car(with front wheel steering) rotates around the center of the rear axle, think of a big nail right thru the center of the diff into the ground. That's the axis a car rotates around when changing directions. The closer the center of mass is to this point, the easier the car changes direction. A rear engine with the rest of the "package" ahead of the axle approaches the ideal "center of mass located at the axis of rotation". This does tax rear wheel traction in lateral load situations. A mid engine is the step in the wrong direction if trying to get a car to steer, but does allow the front axle to support some of the loads. This has some advantages under certain circumstances. Front engine is the same: flawed at some things, good at others. All this aside of roll-center, slip angle, suspension geometry and dozens of other variables should give an idea of the differances.
Rear engine = enter/exit curve very nicely...dicey in the middle
mid engine = not as good at transitioning, but nicely planted in the middle of the curve.
All this can be moderated with chassis set up. Driving style plays a roll, and perhaps a little different line/braking will exploit the traits of either chassis.
One is not better, none of them are wrong.
What happens when adhesion limits are exceeded beyond any "saveable" threshold you ask? Then the car, regardless of chassis, becomes freely dynamic and will rotate around it's center of mass where ever that may be. Forget the rock in a sling BS unless you hold the rock and twirl the sling. Many drivers find that a spinning mid engine car is the worst...they spin uncontrolably and in no predictable direction once past the threshhold.
I expect anyone with "press credentials" to research before writting. This debate should have been given due diligence here before the ill founded opinions were printed in the "zine". Seems as though the OP is following a hidden agenda - I don't know. This lousy thread is simply a biated conflict benefitting nobody except the google analytics of said "zine".
A car(with front wheel steering) rotates around the center of the rear axle, think of a big nail right thru the center of the diff into the ground. That's the axis a car rotates around when changing directions. The closer the center of mass is to this point, the easier the car changes direction. A rear engine with the rest of the "package" ahead of the axle approaches the ideal "center of mass located at the axis of rotation". This does tax rear wheel traction in lateral load situations. A mid engine is the step in the wrong direction if trying to get a car to steer, but does allow the front axle to support some of the loads. This has some advantages under certain circumstances. Front engine is the same: flawed at some things, good at others. All this aside of roll-center, slip angle, suspension geometry and dozens of other variables should give an idea of the differances.
Rear engine = enter/exit curve very nicely...dicey in the middle
mid engine = not as good at transitioning, but nicely planted in the middle of the curve.
All this can be moderated with chassis set up. Driving style plays a roll, and perhaps a little different line/braking will exploit the traits of either chassis.
One is not better, none of them are wrong.
What happens when adhesion limits are exceeded beyond any "saveable" threshold you ask? Then the car, regardless of chassis, becomes freely dynamic and will rotate around it's center of mass where ever that may be. Forget the rock in a sling BS unless you hold the rock and twirl the sling. Many drivers find that a spinning mid engine car is the worst...they spin uncontrolably and in no predictable direction once past the threshhold.
I expect anyone with "press credentials" to research before writting. This debate should have been given due diligence here before the ill founded opinions were printed in the "zine". Seems as though the OP is following a hidden agenda - I don't know. This lousy thread is simply a biated conflict benefitting nobody except the google analytics of said "zine".
07-22-2013, 02:04 PM
#33
4th Gear
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Fatal Flaw
I'm car crazy, owned over a hundred and fifty of them, mostly sports cars. I didn't get my first Porsche until I was 55, because the engine was in the wrong place. Now I am sorry I waited so long. I've sold the vette, the Ferrari, the Lotus and Mercedes. I will keep the Porsche until I die.
07-23-2013, 01:39 AM
#34
Most boring article I've ever read... what was the point? Writing style is terrible, thoughts are unorganized almost random, there's no flow to the "story", and it all just seems like a jumbled collection of attempts to belittle 911's and their owners. Are you trying to be controversial just to get a rise? It worked I guess...
There is no "right" and "wrong" place for an engine, just advantages and disadvantages to each design... and of course, endless opinions.
There is no "right" and "wrong" place for an engine, just advantages and disadvantages to each design... and of course, endless opinions.
