Mid/rear-engine handling

Prepping and driving your Midlana at an autocross or trackday event.
Midlana1
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Mid/rear-engine handling

Postby Midlana1 » 07 Feb 2018, 12:21

This thread may grow into a sticky, we'll see.

I saw this post on a Porsche forum and smiled, as I suspect I'm in the same boat:

One of the things I had to force myself to accept when I first was learning to race [rear-engine Porsches] was "more throttle equals more rear grip". It was very counter-intuitive to me at first.

Luckily I was driving my instructor’s car and he kept pushing me to "Get on the gas!" at corner apex when I "knew" I was at the limit of adhesion.

So I remember thinking "Well I'll show him, I'll do what he asks and then he'll see that the car is going to spin". I mashed the throttle and the car hooked up and flew out of the corner. "Wait, what?!"

Sometime at a trackday event, where a corner exit has huge runoff space, I'm going to have to try exactly this, stomping on the gas even though I "know" it's going to spin off.

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Re: Mid/rear-engine handling

Postby rennkafer » 07 Feb 2018, 14:39

Squeeze, don't stomp. With your hp levels you are certainly capable of lighting up the rear tires and getting the oversteer you asked for or just unweighting the front enough to understeer off instead.

The principle is absolutely correct though, and it applies to all cars, not just rear/mid-engine ones. Tire traction is basically a function of the coefficient of friction between tires and track and normal force downward on the tire. Giving the car some gas increases the normal force on the rear tires through weight transfer.

This is how aero works... more normal force on the tires equals more grip.
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Re: Mid/rear-engine handling

Postby Midlana1 » 12 Feb 2018, 08:45

True, I shouldn't have said that because I know better.

During the crankcase pressure testing I did several 4th-gear pulls on a straight deserted road. The car is effing fast, and if/when there's a road irregularity, and being on cold tires, means it briefly breaks traction. At XXX mph that really gets your attention.


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