Could someone explain this to me please.

The value in the LFS slider says toe-in. So positive is in and negative is out. I get that no problem.

Toe out helps turn in, yes I know that as well; crystal clear in that regards.

But why is it that when I set the fronts having toe-in, the car is WAYYY easier to point into a corner? I thought toe-in is for directional stability. It's boggled my mind for months and especially on south city, I can't ever drive any setup having a front toe-out or even neutral toe.

someone please explain what I'm feeling.

try this for example...

http://www.carbibles.com/tyre_bible.html

Quote from Borbor :

Could someone explain this to me please.

The value in the LFS slider says toe-in. So positive is in and negative is out. I get that no problem.

Toe out helps turn in, yes I know that as well; crystal clear in that regards.

But why is it that when I set the fronts having toe-in, the car is WAYYY easier to point into a corner? I thought toe-in is for directional stability. It's boggled my mind for months and especially on south city, I can't ever drive any setup having a front toe-out or even neutral toe.

someone please explain what I'm feeling.

It may be because of your camber settings. If you have set the camber so that the outside edge runs too cool with no toe-in, then when you add the toe-in the outside edge reaches optimum temp and that gives you the impression of better turn in. You can check this easily by running two consistant laps, one with no toe-in and one with some - see if it effects the temp of the all important outside edge of the tyre.

In the perfect world you'd run 0 degree toe, where possible I try to eliminate toe from all of my setups because it meens that the wheels are not pointing in the same direction as the car, there's a word for this, it's called sliding - and sliding costs precious time.

If you're seeking that perfect setup then it isn't going to be one where the tyres are constantly fighting your direction of travel.

Toe in (with positive camber) is a good way to 'fix' a setup and get a good handling car, but if you can persevere and get a car that handles well without toe in then, all other factors being equal, it's a faster set and the tyres will last longer.

When I do stick toe on a setup I preffer to use toe in rather than toe out at the front otherwise you have to start fiddling with parallel steer.

Quote from Becky Rose :

In the perfect world you'd run 0 degree toe, where possible I try to eliminate toe from all of my setups because it meens that the wheels are not pointing in the same direction as the car, there's a word for this, it's called sliding - and sliding costs precious time.

If you're seeking that perfect setup then it isn't going to be one where the tyres are constantly fighting your direction of travel.

Toe in (with positive camber) is a good way to 'fix' a setup and get a good handling car, but if you can persevere and get a car that handles well without toe in then, all other factors being equal, it's a faster set and the tyres will last longer.

When I do stick toe on a setup I preffer to use toe in rather than toe out at the front otherwise you have to start fiddling with parallel steer.

I always use 0 degree toe at the front too. I often use some toe-in at the back though - particularly on front wheel drive cars where rear tyre temp is only a problem becuase it's too cold. You're quite right to point out that any toe is gonna make the tyre slide across the track surface. If the tyre isn't rotating exactly straight this stands to reason.

As for parallel steer - yes, toe out would mean you would need to lower the % of parallel steer you had set if you do not want to lose grip on slower corners. It makes very little difference in faster turns though. I've always thought that the parallel steer setting in LFS is a bit odd though I have to admit. When would you ever want 0% parallel steer? I'd say anything less than about 85% is just stupid unless I've misinterpreted the way you set this in game.

Doesn't Caroll Smith mention something about Ackerman? He states why it shouldn't be used, but admit he always uses it because it makes pushing the car round the garage a whole lot easier. Anyone got Tune to Win to hand (or whichever one it was)?

Quote from tristancliffe :

Doesn't Caroll Smith mention something about Ackerman? He states why it shouldn't be used, but admit he always uses it because it makes pushing the car round the garage a whole lot easier. Anyone got Tune to Win to hand (or whichever one it was)?

Haven't read that one but Big Ju has. I'll ask him.

In my mind you do need a small amount of Ackerman Angle (non-parallel steer for those who don't know what we're on about) to compensate for the track width of the car and the outside tyre taking a wider cicle than the inside. My belief is that you always want the tyre to be rolling over the track surface straight (this was what Becky eluded to earlier discussing toe), so you must need some Ackerman.

The Staniforth race and rally source book explains how you can work out the theoretically perfect Ackerman Angle based on the cars track width and the corner radius. So Ackerman is more important on tight little circuits. I raced the FXO at Aston Cadet once and I set the parralel steer to 0% and it did improve grip.

From memory the inside wheel should be turning about 10% more than the outside for a fairly tight corner with an average track width but that could be complete b0110x

I also ran no toe in on the front. I could never really see the point. If you have to 'fix' the car with front toe in then you need to fix the car.

But rear toe-in is partilularily helpful with mousers on RWD cars. I always ran between 2-4 maybe even 5 degrees to help the rear control on corner entry and exit. Sure, it scrubs on the straight and saps some speed but the benefits, (Espeacially on sprints) far out wieghed the negatives. Although I had noticed that with the new patch much less toe-in was needed and I was steadily dialing it out of my sets.

Quote from Funnybear :

If you have to 'fix' the car with front toe in then you need to fix the car.

excellent statement...i'll have to remember that one

an understanding of the steering geometry strikes me as the thing most lacking in my understanding of setups. I've read in depth articles on ackermann and alignment, but I still can't get the feel for it very well. I'm not sure whether it's a fault of mine, LFS, or it's always just a fairly experimental aspect of setups.

Can anyone explain the dynamics behind the following situation? uf gtr with 100% parallel steer would snap the tail out quite dramatically as brakes were lifted off at high speed (for high speed sweeping corners) but with parallel steer at 0%, this behaviour was much reduced, and no difference was noted anywhere else. This was on kyoto national but I then stayed with 0% for the rest of the series iirc.

Not sure, but just thought of this as a reason.

With 100% parallel steer, the inside front tyre will slip slightly causing drag. This will change the center of drag of the car laterally and longitudinally, reducing load and grip in the rear wheels, causing the oversteer. With full ackerman (0%) then the front wheels turn the theoretically correct amount, and this drag influence (which surely affects weight transfer) might be less extreme, to an extent the rear tyres retain grip.

I have no idea if that is true, but it sounds plausible.

I don't understand why that effect would only be noticeable when lifting off heavy brakes though - seems like if that were the case I'd have needed to adjust my neutral cornering balance too?

Pass.

But I do find most cars turn in better with parallel steer at 40 to 50% instead of something higher (and zero toe in at the front).

Quote from Blowtus :

an understanding of the steering geometry strikes me as the thing most lacking in my understanding of setups. I've read in depth articles on ackermann and alignment, but I still can't get the feel for it very well. I'm not sure whether it's a fault of mine, LFS, or it's always just a fairly experimental aspect of setups.

Can anyone explain the dynamics behind the following situation? uf gtr with 100% parallel steer would snap the tail out quite dramatically as brakes were lifted off at high speed (for high speed sweeping corners) but with parallel steer at 0%, this behaviour was much reduced, and no difference was noted anywhere else. This was on kyoto national but I then stayed with 0% for the rest of the series iirc.

My guess is that you are ending up with too much toe-in on the outside tyre for the fast corner once you set the parallel steer to 0%. This will reduce the amount of grip available at the front drammatically meaning less oversteer. Remember, you need a higher parallel steer percentage for fast corners.

What is the camel-toe? Someone told me I need a lot of it if I want smooth ride???

Quote from CSU1 :

What is the camel-toe? Someone told me I need a lot of it if I want smooth ride???

Camel-toe - a nasty skin complaint that effects the feet. Symptoms include abnormal hair and nail growth. Brought on by extreme exposure to sand. lol

Quote from Gentlefoot :

Camel-toe - a nasty skin complaint that effects the feet. Symptoms include abnormal hair and nail growth. Brought on by extreme exposure to sand. lol

ROFL my bellie hurts

on a FWD racing car you would normally run some degree of toe-out (the front of the back wheel toe'd out) to help it turn in.
FWD cars are always quicker with a little bit of oversteer. visa-versa for RWD.
sure toe in/out slows you in a straight line (slightly) but you can agin an awful lot in the corners. it's just a matter of getting the balance right.

Quote from nikimere :

on a FWD racing car you would normally run some degree of toe-out (the front of the back wheel toe'd out) to help it turn in.
FWD cars are always quicker with a little bit of oversteer. visa-versa for RWD.
sure toe in/out slows you in a straight line (slightly) but you can agin an awful lot in the corners. it's just a matter of getting the balance right.

I agree - I have 2 mm toe-out on my Golf IRL. But in LFS I always have toe straight on FWD. This just helps to keep the outside edge cooler and then I can run less pressure. I find you can get the turn in you need by reducing front bump. I guess this just suits my driving style tho.

But then you're faster than me so what do I know!

Quote from Gentlefoot :

My guess is that you are ending up with too much toe-in on the outside tyre for the fast corner once you set the parallel steer to 0%. This will reduce the amount of grip available at the front drammatically meaning less oversteer. Remember, you need a higher parallel steer percentage for fast corners.

Like I said, it was only in the transition phase though - entry without brakes, mid corner, and exit, were unaffected. I guess it's things like that that are hindering my understanding... I'm going to make a point of experimenting more with the steering settings for my lx6 set this week.

It could maybe be tyre flex as well.

If your going from hard braking to acceleration which is to say a low load on the rear tyres to a high load then the tyre is going from stretched to compressed. Espiacially as you are cornering as well so the tyre is deforming, which will be extrolated once your back on the power. That 'grip shift' might induce jump as the tyre tries to snap back into shape.

Although why that would only happen with one setup and not another I don't know and I'm probs not right anyway . . .

What I love about this forum/sim is that faced with a problem (e.g. this transitional oversteer) we try and think of workable semi-technical reasons and solutions. From what I've seen on other 'sim' forums, people ask a technical question, and the answer is either 'try another mod you noob', 'who cares, just learn to drive', 'use a different setup, here's a list of 500 crap ones', or 'why do you care, you once wrote a positive post about another sim, so we don't like you anymore'.

As someone said in another thread, there's fanboys and then there are fanmen

Lfs enables you to do that though. You have enough faith in the physics and the setup options that you can work through them in a logical fashion. There are obviously some flaws in the plan (the fabled Aero bug for one) that slip through, but on the whole is just shows you how good LFS is that people can talk through a particular problem, test it, theorise about it and (hopefully) solve it.

Way to go LFS . . . I'm in love all over again.

Quote from Blowtus :

Like I said, it was only in the transition phase though - entry without brakes, mid corner, and exit, were unaffected. I guess it's things like that that are hindering my understanding... I'm going to make a point of experimenting more with the steering settings for my lx6 set this week.

OK yes it's during the transitions phase but nevertheless, when all the weight is over the front that is when you would notice the problem. There aren't many good sets that oversteer in a neutral state.

any other car and I'd probably agree with you I ran totally pumped rear tyres and a very oversteery set, partially compensated for with a 7000rpm idle (dxtweak2 fun) with great success all series - once I'd ironed out that nasty brake reduction snap oversteer. Next time I fire up LFS I'll spend a few minutes checking out this situation again though, and see if lots of toe in causes a similar effect - will help square it up in my mind if nothing else.