Jackie Stewart always went into a corner neutral, not gear but no gas no brakes. He seemed to do OK at it.

its almost like we've learned something about driving in the last *checks notes* 60 years.

proper braking means you will be using the brake on corner entry. its faster. period.

ahh perhaps we are saying the same thing.
The apex of the corner determines where I apex my car.
When I apex the car I'm on gas, to get back on top of the tire.
I like a lot of roll speed mid corner.
Track out thru a little power oversteer on less than perfect asphalt, helps rotation.

PCA teaches pitch and catch, requires gas/brake weight transfer car control.

Neutral is like neuter. :p

I have an admission to make, I like to left foot brake.
Sometimes when I'm on top of the tire I load up the brake and gas at the same time.
And no it's not in a 935 or a turbo car.

Shifting a Dog ring box or towing downhill neutral not recommended.

Low revs. Less noice. More comfortably sailing. SmileWavy

Depends on what yer driving.
Rules are different with a solid axel and no diff.
Rules are also different with high downforce.

There are solid axel vehichles out there where the weight is going to concentrate on the outside wheels leaving the inside wheels almost, or actually floating.
With a lack of differential not being on throttle will cause understeer that has to be overcome by even more steering angle.
This is because the outside rear under engine braking will be dragging against the desired direction of rotation.
It creates a massive friction fight, kills momentum and cornering force both.
In such a vehichle, feathering on throttle after corner weight transfer is akin to pushing the rear corner of a peice of paper across your desk.
Less steering angle is required, better conservation of momentum, and higher cornering force.

trailing throttle oversteer much? ;)
you never push in the clutch it will roll.
over and over.

I hate to say it but a lot of this is wrong, too.

I probably still have some vehicle dynamics books left over from all the books I sold. Maybe I should look through them and offer them up for sale here…

Till some yokel does something and you need to get out of that corner fast.
Staying in gear adds control. fact.
it determines your ability to change your energy state fast


its like standing at the red lights.. in neutral
No bueno , cannot get away fast if a truck comes barreling on to you

being at an intersection waiting... with your wheels already turned to cross.. no bueno somebody rear ends you and you shoot into upcoming traffic.

Neutral has no purpose or merit other then at the MdDonalds Drive, or in a fully developed Tjam

I'm not an instructor, I tried to explain why it worked for me but to be fair maybe maybe the explanation sucks, but I do know neutral doesn't work in practice. And that At least my driving isn't wrong I just can't explain what I do and have ben doing right for 20 years, based in trial and error. Been on race tracks and the Porsche instructor saw me drive and said I was doing allright. Which matters more to me then my abilty to explain it :D

Trailbraking and oversteer etc , sure those work but technically those are workarounds for special circumstances.
Like odd surfaces or special combinations in corners.

In a single turn
a consistance turn angle
even surface
Straight line in
Straight line out
There would be only 1 way to get through it in an ideal way fastest way for a specific car
and it would not involve trail braking with oversteer.
or it would have to be a hairpin bend.. a hand brake turn so to speak

Which well you'de probably want the clutch in for that so your engine does'nt stall along with the wheels stopping:D

this doesnt make sense at all.

trail braking, or as we call it, braking properly, does not mean you are oversteering. and braking properly will always be faster than releasing the brake before turn in.

if you trail brake while steering in , it will destabilize your back end, which if you do it long enough will induce oversteer
it changes the balance of your car depending
understeer in , trail brake, transfer weight to get oversteer.

https://youtu.be/tvcuGoVhpxw?t=499

Right, overcooking the corner is bad. If the car was in gear and you were on the gas, but going too fast, it still would have been bad or at least would have required letting off and/or braking.

But this question is NOT about best practice for safety or traffic. This question is about the PHYSICs of how the car will handle coasting in neutral. So, imagine you were on a beautifully smooth track with no curbs and great traps to ensure that you don't go off and hit something and no other cars. If you could get up to 90 and roll through a fast sweeper in neutral is the car going to gradually lose speed but be just fine or pirouette or explode or ....

Yep, I get it and I think that you're probably a fine driver. I think you understand how it works on a track or the road in practice.

I think the main problem is that you're answering a slightly different question (fastest way through/around a corner or best way on a track to go through a corner or something like that) instead of "is this old statement true? Will coasting work from a physics point of view, or is there something about the physics of coasting in neutral that would make the car handle weird."

In many ways, you're probably better suited to say this than I have. I've driven aggressively, but never been on a track. So most of you will stop reading.

I've also read a bunch of books on driving, Bondurant, Frere, Watts, etc..., and I've taken a bunch of physics, so I think between those books, my understanding of the physics discussions, and my aggressive driving (where I actually test theories and what I've read).

Oversteer (sliding rear tires) is probably rarely the best way (it's slow) to come out of a corner. Trail braking to the point that you've got a large slip angle, but you aren't sliding (sliding, leaving black marks, making tire smoke), is probably usually the fastest way into a corner. Then I would assume the fastest way out, most often, is to feed in the throttle to reduce the rear slip angle but increase the front slip angle.

Even if the corner is at the end of a long straight before a short straight (fast in, late apex, slow out) or at the end of a short straight before a long fast straight (slow in, early apex, fast out), I suspect you'd still want to use trail braking with high rear slip angle and then feed the throttle to get higher front slip angle, but the lines and amounts of trail braking and throttle feeding would be different and swap at different points.

But it's not coasting perse.

If its coasting; no brakes either..
you gave up ALL controle over the balance.

you have to steer, you cannot avoid that
and steering will make the car weight move around to the outside
you cannot control it in any way except for not steering.

In reality; neutral you will still the brake pedal.

So for RWD, that braking pedal will be on you front wheels with a +- 70 % front bias. and those tires are already working for the steering part.

So not coasting leaves you with only one way to play with the balance
1 its one way only.. you cannot unbrake
2 it affects the grip level of your wheels who are steering
3 your rear wheels aren't doing anything for you other then rolling

it is all about controlling the weight
and coasting or neutral with brake pedal usage is pisspoor control of that weight

It's like cycling with your feet off the pedals
sure you can go down a hill like that
but you won't like it for long

Right, but the question isn't "is this a good way to do it" the question is "will it work"

So, lets say with Stijn driving his Cayman, at the track, he can take a particular corner (flat track, no uphill or downhill) at 60mph. If I was going 70 down the straight, put the car in neutral, and then hit the brakes to get the car down to 60 or 58 or 55, would I be able to steer through the corner (I believe as soon as you turn the steering wheel, the car will begin to decelerate). I believe that in neutral, the car will be able to be steered around the corner at pretty close to the same speed. Hell, you may be able to go into the corner at 62, 63 or 65, and let the turn scrub off the few mph so you're still at ~60 mid-corner.

it all depends on the the corner, and speed you enter
if the speed is below what your car weight , balance and tires can handle, then yes you can coast
if not, you will exit the corner the wrong way

no control , no way to do something bout the excess speed

Most people will be unable to precisely estimate what the ultimate limit for coasting is.
So unless you UNDER estimate with big margin, eg granny it ; you are screwed

You can incrementally test the speeds , creep up and up and up
you will find out when you go out the corner that the previous speed was the limit

EDIT, oh yeah predict it will be understeer, you'll see the tree coming.

Take a riding mower with a locked rear drive axle onto pavement.
Put it in neutral and hold the steering over to lock and try to push it in a U-turn from a stop.


Then push it to a few MPH while straight, and then try to make that same U-turn while pushing.
The weight transfer off the inside will free up the rear bind.

Now most of us are not stuntmen, and I don't recommend trying this, but under power get enough weight transfer the inside rear just comes a paper's thickness off the ground on turn in and feather in some throttle.

You'll be able to reduce the slip at both front and rear as the bind from the inside rear is no longer a factor, and the slight torque steer from the outside rear is in your favor instead of against if under engine braking.

I’d like you to explain the physics of transferring all of the weight off of the inside rear tire to the outside rear tire, just by locking the rear axle.

You know, just enough to get that piece of paper under the inside tire.

Go for it.

The weight transfer from turn in/cornering is doing that.

Two things. One you don’t transfer that much weight. Two, it has nothing to do with whether the axle is locked or not. So go ahead tell me how a locked axle transfers weight differently than a differential.

Torque (accompanies high revs) holds the car down.

Torque is a rotational force, with rear wheel drive this turns the wheelbase of the car into a lever arm, resulting in the front end being pushed down - increasing road holding handling.

It's probably easier to test out the opposite, lift suddenly off the gas in a turn and the front end will lift - maybe scary and expensive - WARNING.

The purpose of lifting the inside rear is because of the locked axle without a diff rather than the other way around.

Front geometry is part of getting the inside rear lift but it also takes weight transfer to finish the job.

You’re dodging my question. Why don’t you give us the formula for lateral weight transfer on an axle?

I've waited a little bit to type this, but when was the last time you had a mental evaluation javadog?
You say I'm dodging a question; but the question is about a position I never had.

Questioning my mental health, that’s not nice.

I believe your position is that whether a drive axle has a differential or not affects the transfer of load on that axle in the corner. You seem to think that solid axle cars transfer a load differently. I’m telling you the differential has absolutely nothing to do with load transfer.

So I’ve asked you to explain your position. Pretty simple.

...
And...

Oh so repetitive…. You missed one.

Feel free to elaborate on this nonsense. ^^^^

Then tell me how the question of what differential type is there affects the load transfer.

To save you some time, I will tell you that the lateral load transfer is dependent upon the lateral force being applied through the center of mass, the height of the center of mass above the ground and the wheel track distance. That simplifies it a little bit, as we are not differentiating between sprung and unsparing masses, but it will be sufficient for our discussion.

Personally, I think you’re losing the plot here and it’s not load transfer that’s the issue. Differential types do have an affect on the handling but it’s not because they change the amount of load that is transferred.

I've been wondering for a bit, exactly what you mean by this. I don't get it.
I don't think it's normal to design a car to lift the inside tire, front or rear, completely off the ground or even to where it's just kissing the ground. Granted, anti-roll bars do exactly that, lift the tire on the side opposite to the side being compressed with the purpose of increasing lateral load transfer on that axle. That action actually decreases the traction available on that axle.

Right, whether a solid rear axle has an open diff, torque biasing diff, plate based LSD or is a spool is not going to change the weight distribution in a corner. They'll all affect cornering, but not by altering weight distribution.

IRS vs solid axle is something else entirely.

If you’re lifting an inside wheel, at one end or the other, off of the ground when cornering, you’ve missed the boat on the relationship between the front and rear roll stiffness. And maybe you don’t have enough droop travel.

Air-cooled 911s will lift the inside front tire in a corner but that’s because the car design is fundamentally crap. State of the art suspension, circa late 1950s, coupled with a fairly stupid mass distribution…

It's intentional in a lot of solid axle race formats on tracks with both left and right tight turns.
It removes the undesirable fight between the inside and outside wheel taking a different radius around the corner.
It also results in accelerating or braking torque vectoring from the outside rear wheel.
On longer radius turns the difference between the radius the left and right follows is significantly less while on tighter turns it is more pronounced.

Navigating a set of narrow hairpin switchbacks in a solid axle vehicle with fat tires getting that "kiss" of the inside in almost no contact while feathering the throttle will reduce scrubbed friction and leave more grip for cornering.

On the other hand in high speed long radius corners with a high powered vehicle having the inside rear floating is not going to be desirable as the heat of that power will be going into one tire.

To understand better find a vehichle with a locked rear axle, doesn't have to be a car.
Hold the steering to lock and corner at half a MPH.
Do it again at the appropriate speed to get a good weight transfer going, feather on some throttle and do not skid the outside tires and the resulting corner radius will be tighter at full steering lock than when creeping it.

930 is a handfull. my rear end sticks up too much, stock suspension and setup.
i am back in the gas (just a little) after turn in, depending on how much i let the rear "turn" the car. i wasnt quick enough back in the gas last time out and i managed a nice 360. first time spinning it. :D

that long turn i do under hard acceleration and having to shift while turning made me nervous at first in my 930. clutch in to shift always felt stable. i was worried about weight shifting when i put in the clutch.

you not understanding how trail braking works is not an argument against it.

trail braking achieves two things, and why i teach trail braking as normal, not some special thing (yes, i am a driving instructor):

1. you can brake later. this is intuitive to having more speed, you carry more speed longer, and that means your faster.
2. trail brake to kill understeer. this allows you to turn in at faster speeds than a straight line breaker would. which means you have faster apex speed, and a faster slowest cornering speed. this leads to faster straight line speed to because you got off the corner faster.

if you are in significant oversteer on entry, you held on too long.

This thread is an excellent example of how most of us learn from doing something rather than hearing an explanation we don't understand because of incomplete or imprecise language or an incomplete frame of reference.

Lighten up please gentlemen, you don't usually change a person's mind by attacking them.

Best
Les

Didnt you just confirm what i said?

Btw i never said never trail brake.
Were are debating why not to be in neutral and coast through 1 single fixed radius turn.

We arent talking about racing and combination of turns. Or outbraking or taking alternative lines

For 1 single fixed radius turn i see no trailbraking as the solution to get trough that turn as the fatest way.


Trailbraking is for variable conditions. Workarounds to things that take the driving away from the ideal line on a single fixed radius turn.. to keep it together despite people driving around you. For combinationsnof turns increasing or decreasing radius turns. All hose things . Trailbraking is 1 thing in the bag of tricks.

But we arent taling about racing or all the variables

We are taling about neutral through 1 corner

Quite frankly diacussig all the variables will never work in text cause its way too dynamic

Years back did an autocross school with the 911. Took one time around the circle portion of the course with the instructor explaining how to widen or tighten the diameter with the throttle to get a feel for it.

In a 911 for sure you need to be able to shift that weight back over the rear wheels and that's kinda tough if you aren't in gear.

2:45 mark..................in a turn keep the throttle steady to keep the car balanced...............

https://www.youtube.com/watch?v=rKf2fRImrYI
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Does not claim side to side balance nor front to back balance, rather vague........... but I like this video's tips on adjusting the drivers position.

3:20...........in a turn keep the car under-load either decelerating or accelerating to maintain balance..........don't coast.......