Taking a curve in neutral ?

[javadog]

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.

[Tervuren]

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

Originally Posted by javadog

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.

[javadog]

Originally Posted by Tervuren

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.

[kach22i]

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.

[Tervuren]

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.

[javadog]

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

[Tervuren]

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.

[javadog]

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.

[Tervuren]

...

Originally Posted by Tervuren

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

Originally Posted by Tervuren

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

Originally Posted by Tervuren

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

Originally Posted by Tervuren

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

And...

Originally Posted by Tervuren

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.

Originally Posted by Tervuren

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.

Originally Posted by Tervuren

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.

Originally Posted by Tervuren

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.

[javadog]

Oh so repetitive…. You missed one.

Originally Posted by Tervuren

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.

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.

[masraum]

Originally Posted by Tervuren

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.

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.

[masraum]

Originally Posted by javadog

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

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.

[javadog]

Originally Posted by masraum

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.

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…

[Tervuren]

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.

Originally Posted by masraum

I've been wondering for a bit, exactly what you mean by this. I don't get it.

[T77911S]

Originally Posted by ted

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

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.

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.

[cockerpunk]

Originally Posted by svandamme

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

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.

[oldE]

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

[svandamme]

Originally Posted by cockerpunk

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.

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

[berettafan]

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.

[kach22i]

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

https://www.youtube.com/watch?v=rKf2fRImrYI


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.......