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Discussion Starter #1
...i'm developing my feel for throttle response in turns, and one thing which puzzles me is the adage to never lift, but rather to power through a turn in order to stick better...

...it's something i'm getting an intuitive feel for now, the way the balance shifts and the car's just so much more stable turning under acceleration, but i can't wrap my head around the physics involved...i understand how braking through a turn consumes more of the traction which would otherwise be available to stick the turn, creating understeer, and i understand how increasing power pushes the rear wheels out more behind the guiding front wheels, creating oversteer, but i don't understand how reduced throttle or coasting through a turn ends up sticking less than powering through, since it seems like acceleration would consume some of the traction available for steering just as much as braking...

...intuitively, while driving, what i feel is this: slower/lifted turns are more stable up to a certain low-speed threshold where a different set of handling dynamics kick in, above which lifted turns can no longer stick on their own but powering through keeps the turn stable instead...is my intuitive feel correct, and can someone explain this phenomenon to my analytic side?..
 

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Lifting (abruptly) makes the rear end light, thereby creating snap oversteer. The front of the car will bite toward the inside of the turn instantaneously, and the rear will spin around toward the outside of the turn.
 

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Discussion Starter #3
...so it's all about weight distribution bias toward the rear wheels under power providing more lateral traction from the rear wheels to help stick the turn, which otherwise wouldn't be there while coasting?..
 

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The key is managing the weight of the car through the turn. Put the weight where you need traction. On initial turn in you generally need more traction in the front which is wear trail braking can come in handy. Around Apex (usually before apex) you will need to get back on the throttle to move some of the traction towards the back. Normally at apex to the track out point you will be at full throttle as the majority of your turning is done.
 

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Its more about not upsetting the weight distribution of the car going into the turn...abruptly. :D And what Chili Red said. :)
 

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...but i can't wrap my head around the physics involved...i understand how braking through a turn consumes more of the traction which would otherwise be available to stick the turn, creating understeer, and i understand how increasing power pushes the rear wheels out more behind the guiding front wheels, creating oversteer...
The physics that you are describing is not correct.
Imagine a motorcycle with the front wheel in the air.
Is that oversteering or understeering?

When you decellerate there is more weight on the front than on the back.
Look at the front end and see if it goes down. (it does)
Then sit on the front clam and see if it goes down. (again it does)
The only way for the springs to compress is from more force.
(More force downwards on the tires)

The rear also lifts up when you decellerate.
Now lift up on the rear end.
(Less force downwards on the tires)

The mass of the car is unchanged though, just how much weight is pressing down in the front versus the back...
From high school physics we know that F=MA or dividing both sides by M we get (F/M = A)
If the F is the sideways force - then it is proportional to the downward weight (really it is downward force) times the stickyness of the tyres.
If you lift the front up then there is less F so there is less A.
If the front sideways acceleration exceeds the rear you spin.
The back exceeding the front causes pushing or understeer.

If you are burying the throttle, then you are using more force in the front to rear direction so less is available for the sideways stuff.
Massing acceleration oversteer is a different phenomena than lift off oversteer.

Class is over - where is the teacher's apple?


{edit} If you're in a turn where the radius is decreasing - then the only sensible thing to do is enter it with less speed. Staying on the throttle is not likely intuitively obvious, nor can you get more corning force as the turn decreases... You'll realize that you've screwed up and the prayers will start. There is no magic available for getting through it, other than keeping it balanced and hoping that you bleed of enough speed to stay on the pavement {end edit}
 

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Discussion Starter #7
If you're in a turn where the radius is decreasing - then the only sensible thing to do is enter it with less speed. There is no magic available for getting through it, other than keeping it balanced and hoping that you bleed of enough speed to stay on the pavement.
...so the only really safe way to negotiate that situation is to enter slowly with a healthy margin for error and then gradually ramp up entry speed as one comes to know the turn better, it seems - no shortcut around practice...

...do professional drivers typically get in plenty of practice time before they race a circuit, or are they able to rely upon experience to gauge new turns sight unseen?..
 

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...so the only really safe way to negotiate that situation is to enter slowly with a healthy margin for error and then gradually ramp up entry speed as one comes to know the turn better, it seems - no shortcut around practice...

...do professional drivers typically get in plenty of practice time before they race a circuit, or are they able to rely upon experience to gauge new turns sight unseen?..
I am no where near a professional driver, but.....

That said, When ever I come onto a corner hot enough that the car understeers, WHILE MY RIGHT FOOT IS STILL ON THE GAS, I jab the brake just a bit with my left foot to stop the understeer, I give it more gas as soon as it sticks and power out the rest of the corner.

I have pushed and PUSHED this car and never spun it, 6months into ownership bought it WITH a turbo...
 

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The phrase, "never lift," is not accurate. It is a safety generalization intended to briefly cover a long, long list of widely variable conditions.

What it should be is, "usually don't lift very much." And it should be followed by hours and hours of classroom discussion and in-car instruction so eventually your brain can make all the new neuron connections required to properly determine the "when" and the "how much."

xtn
 

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{edit} If you're in a turn where the radius is decreasing - then the only sensible thing to do is enter it with less speed. Staying on the throttle is not likely intuitively obvious, nor can you get more corning force as the turn decreases... You'll realize that you've screwed up and the prayers will start. There is no magic available for getting through it, other than keeping it balanced and hoping that you bleed of enough speed to stay on the pavement {end edit}
Decreasing radius turns can be extremely fun if you know how to drive them. You can enter way faster than you can complete the turn if you enter trail braking. You just need to scrub speed through the first part of the turn possibly adding a bit of a lift mid turn to get the car to rotate a bit more. IMO the lotus really shines in this type of corner.
 

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"Lifting" Question

I don't have my Lotus yet, but will be getting one soon. I have a stupid question regarding lifting...

I understand the physics and the what's and why's.

My stupid question is:

What do you do if you are pushing hard through a corner and are suddenly obstructed (dear runs out, blind long turn and then there's a truck in front of you, etc.)?

If you hit the brakes or lift, doesn't that still throw the weight forward? Obviouslt the difference being that the brakes are evenly slowing all 4 wheels down. But does breaking give you traction while you are slowing and shifting weight forward?

I'm not talking about just lifting because you feel you're losing control of the car. I'm talking about slowing or even stopping due to a hazard of some kind...

I'm pretty sure I know the answer but I would rather ask a stupid question and suffer ridicule then not ask and get into an accident... Then again, it is better to keep your mouth shut and let everyone think your a fool then to open your mouth and prove it. :)

-Matt
 

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Yes--the result is the same, independent of the initiating event.
 

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I don't have my Lotus yet, but will be getting one soon. I have a question regarding lifting...

I understand the physics and the what's and why's.

My question is:

What do you do if you are pushing hard through a corner and are suddenly obstructed (dear runs out, blind long turn and then there's a truck in front of you, etc.)?

If you hit the brakes or lift, doesn't that still throw the weight forward and send you into a spin?

I'm not talking about just lifting because you feel you're losing control of the car. I'm talking about slowing or even stopping due to a hazard of some kind...

-Matt
First off, you should not be driving fast enough of the street where lifting will make a difference. Lifting really only comes into play when your at or near the limit of adhesion.

Honestly its really hard to say what to do in that situation without being there. Normally you will have a few options, steer around said deer/truck, drive off onto shoulder or grass, put both feet in and pray. However you really should not put your self in that situation.
 

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or aim for something cheap..rotfl
i read these discussions of turning and the memories of the formula junior i've driven, come flooding back.
it was the first time i had driven anything balanced well enough and with enough power to weight to be able to change the line with throttle.
the discovery came at marlboro track in virginia.
i'd love to have the reflexes back to take the elise and try it again.
sam the old man
 

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or aim for something cheap..rotfl
i read these discussions of turning and the memories of the formula junior i've driven, come flooding back.
it was the first time i had driven anything balanced well enough and with enough power to weight to be able to change the line with throttle.
the discovery came at marlboro track in virginia.
i'd love to have the reflexes back to take the elise and try it again.
sam the old man
Changing the line with the throttle has always been second nature to me. Changing the line with the brakes, however, is a never ending (and FUN) challenge!

One of my instructors at Skip Barber said, "The last thing anyone gets good at is braking. It's the last thing you'll master and it takes the longest to do so."
 

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First off, you should not be driving fast enough of the street where lifting will make a difference. Lifting really only comes into play when your at or near the limit of adhesion.

Honestly its really hard to say what to do in that situation without being there. Normally you will have a few options, steer around said deer/truck, drive off onto shoulder or grass, put both feet in and pray. However you really should not put your self in that situation.
+10 on this one. If you are driving at the limit on the street you're not only putting your life at risk, but the life of others.

If you have a need for speed, at least be smart about it and go to a track day once a month. Last time I checked they did not allow big trucks or other dangerous objects onto the track, so the OP's issue is moot.

Or look at it another way, that ticket you are going to get for driving 20, 30, 40+ over is going to cost you at least a couple hundred bucks to pay off, not to mention the monthly ding on your insurance. Why not spend the money at the local track and save yourself the headache of having to show up in court.

One final thought, if you are at the track, driving at the limit and something unexpected happens (deer runs across the track, your foot slips off a pedal, etc..) you got to make some decisions about how you are going to use the traction that you do have to your advantage so you can walk away from whatever happens. There are so many potential variables, (including your own ability to react) and things will be happening so fast that further speculation is pretty pointless. Kind of like speculating / wondering about what you'd do if someone points a loaded gun at you. It likely will happen so fast that you only have time to react to the specific situation and hope for the best.
 

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Everyone is pretty much right on this except for the comment that these cars won't spin. Wrong. When the car is at the limit of adhesion, any little thing can upset it and then, under WOT, the rear can come around really fast. The lack of polar momentum in a mid-engine car makes the spin quick and, fortunately, tight, so you are more likely to stay on or near the asphalt, but it is harder to correct than in a car with front or rear engine. Of course, this characteristic is exploited by the pros which is why mid-engine is the layout of choice for race cars.
 

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The phrase, "never lift," is not accurate. It is a safety generalization intended to briefly cover a long, long list of widely variable conditions.

What it should be is, "usually don't lift very much." And it should be followed by hours and hours of classroom discussion and in-car instruction so eventually your brain can make all the new neuron connections required to properly determine the "when" and the "how much."

xtn
+1

"Never lift" is just like "Always brake in a straight line".

It's GREAT advice for folks who are learning, but after hours and hours of classroom and in-car instruction, you do learn how you can lift in a corner and brake in a corner effectively. But trying to teach EVERYTHING that can be done with a car on a track is too overwhelming, so they take the hard parts (throttle steering and trail braking) out to focus on the easy parts (the line, regular steering, and straight line braking).
 

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OK, maybe I've misunderstood some posts...

I'm not a psycho driver (I'm a physician with 3 kids) but I certainly enjoy pushing my car a bit when the opportunity arises...

I currently drive an Audi RS-4 with four wheel Quatro and it never flinches, ever. At any speed. I turn the wheel, the car turns, the tires stick. Period... Between it's traction control, huge breaks, four wheel drive and huge tires it's a wonder to drive and very forgiving. My old mustang was way less forgiving...

Based on my readings of several threads, I got the sincere feeling that if you pushed the car hard through an off ramp at 50 or 60 and lifted, then off you'd go... I'm not talking over 100 or anything.

I guess I'll just have to wait to get the car to feel it out.

:shift:

Thanks.

-Matt
 
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