Official alignment values thread

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GOD!

This thread is full of idiots!!!

Where in the hell did any of you learn anything? Cracker Jack Box Trivia?


Toe IN = / \ = Possitive (+) Number

Toe OUT = \ / = Negative (-) Number


When it comes to chassis setup, ALL negative numbers are associated with moving AWAY from the centerline of the chassis.

If you have Negative Caster, your wheels are toed outward, away from the centerline of the chassis.

If you have Negative Camber, the top of the wheel is pointed AWAY from teh chassis.

ANd the oposite is true for positive numbers.




This isnt difficult to figure out.




As for the F1 cars in GT3 being toed out in the rear, this was to help improve turn-in under throttle.

Witht he mid engine layout, the force of the chassis dynamics is directly applied to the rear wheels during acceleration. Thus making the grip levels of the front wheels less, and making their turining ability greatly limited. If you add in a couple degrees of negative caster, and toe the wheels out, when the car is in a turn, and you depress the throttle, the toe out of the loaded rear wheel, will force the car to rotate inward tword teh apex, as the wheel tries to "straighten itself". This effect can only truely be utilised if the differential settings allow for it. Without the proper bias, you would just spin out. But with the corret amount of toe out, and possitive traction bias in the differentials settings, you can improve the steering of the car under accaleration, and improve corner exit speed. This is a little trick that has been done for years in open wheel racing. And is still used in smaller formula series such as the Mazda Star Series, THe Dodge barber Pro Series, Formula Nippon, and Formula 3000. F1 doesnt use that technique much often anymore, except on tight courses like Monaco, becuase most of the mechanicle advantage for turn-in from tow out, can now be controlled via the electronic differentials, and traction control. Allowing for 0-toe or possitive toe settings to improve high speed stability, and tire wear.


Seriously, this thread should have ended on the first page.
 
Buck-O
GOD!

This thread is full of idiots!!!

Where in the hell did any of you learn anything? Cracker Jack Box Trivia?

When it comes to chassis setup, ALL negative numbers are associated with moving AWAY from the centerline of the chassis.

If you have Negative Caster, your wheels are toed outward, away from the centerline of the chassis.

If you have Negative Camber, the top of the wheel is pointed AWAY from teh chassis.

ANd the oposite is true for positive numbers.

This isnt difficult to figure out.
Click to expand...
Well, apparently it is difficult to figure out, because you're wrong about camber. NEGATIVE camber is when the top of the wheel tips in TOWARD the chassis centerline. GT3 and GT4, at least, have always gotten this wrong as well.

And caster has nothing to do with the chassis centerline at all. It has to do with how the steering axis is tipped vertically fore-and-aft parallel to the chassis centerline, not towards or away from it. It also has absolutely nothing to do with whether the wheels are toed in or out.

Kindly refrain from calling people idiots in the future... particularly when you have no better grasp of the subject than they do.
 
Buck-O
GOD!
This thread is full of idiots!!!
Click to expand...
Really...

Buck-o
If you have Negative Caster, your wheels are toed outward, away from the centerline of the chassis.
Click to expand...
You don't know what caster is.

Buck-O
If you have Negative Camber, the top of the wheel is pointed AWAY from teh chassis.
Click to expand...
The only positive thing I can say is that this supports your first comment.


Buck-o
Witht he mid engine layout, the force of the chassis dynamics is directly applied to the rear wheels during acceleration. Thus making the grip levels of the front wheels less, and making their turining ability greatly limited.
Click to expand...
OK guy...
 
No you can't add camber or toe adjustments to the driven wheels in a live axle car.
Click to expand...

I'd just like to point out that you CAN add camber and toe to a solid axle by heating and bending the tubes. This is done on alot of older American Iron type cars, but it is limited to about +/- 1 degree, as anything more results in alot of stress on the axle splines.

As for the game description of toe being +/-. Uh... I dunno?! Wish I knew. There are alot of things in this game I'm finding to be rather unpolished.
 
Toe-in is negative in both the front & rear while toe-out is positive in both front & rear...

I'm sure of this...

The Mazda Miata mx-5 is a very nice car to test this on as little differences in an alignment will have a major effect on this tiny little car...

If you don't believe me, try 3 toe up front; you'll notice it oversteers badly, is twitchy and hard to control while braking... Now try -3 toe up front... You should find most of that oversteer is gone, is much more stable and easier to handle...

Do the same for the rear.
 
From http://autorepair.about.com/cs/generalinfo/a/aa012201a.htm , as posted above. Since people are still making posts on this, I thought I'd hammer the nail a little more :dopey:

Toe is a measurement of how much the front and/or rear wheels are turned in or out from a straight-ahead position. When the wheels are turned in, toe is positive (+). When the wheels are turned out, toe is negative (-).
Click to expand...

I'm just happy I found out, I can finally get some sleep :dunce:
 
Yes that is how it is in the real world, Ske...

Though some say in Japan they measure toe just the opposite of the rest the world; that is toe out being positive...
 
I still stand by my logic, positive toe is toe out, whether it is front or rear. But here's a different perspective on the subject. I set up track cars at work and we never go more than 0.25 degrees of toe in. That's -0.25.

This is because excessive toe will reduce your top speed potential because you're scrubbing the wheels more. I know it hardly affects things in the game as far as top speed and tire wear but we don't try compromise the toe to tune the handling. The answer is usually elsewhere.

I find that differential settings and camber settings make the most difference (once I have my spring rates and damper settings selected). Most of my garage have minimal toe adjustments, mostly zero, and handle fine (I know, it's subjective). Let's say predictable and tossable. Except for that damn 22B. Thing pushes like a pig.
 
FFS - can't we just have a straight answer to a single tuning question?

Is 'negative toe', 'in' or 'out' on GT4?

One definative answer please!
 
Nagarjuna,

We don't know... Anyone that tells you one way or the other is just stating there opinion. It is pretty much half of us believe toe-in is negative while the other half believe toe-out is negative...

You could give us one more opinion on this matter... Take your car, preferably a FR (front engine, rear drive), and give it -4 toe in back... How does it handle: understeer or oversteer? Twitchy or stable?

Now goto +4 toe in back, ask yourself the same two questions...

The setting where it feels more stable and experience more understeer would be toe-in... The setting that feels "twitchier" and you experience oversteer would be toe-out...

Couple big reasons for the confusion... One of them being that PD never told us what the values mean, they didn't even give us a diagram like they did in gt3 (even if it was impossible to read).... Other issue is that a negative value represents toe-in while a positive toe is toe-out if you've ever read your specs after you've got an alighnment done... In Japan (plus some rare alignment shops) they "reportedly" use just the opposite, that being toe-in being positive and toe-out being negative...

Test it yourself, see if you can solve this mystery.
 
For what it is worth, I did HND and Degree in automotive engineering, and honestly, after the argument going through this thread, I am not sure what to believe anymore! But let me see if I can appeal to anyones sense of reason, and get some of the more talented drivers on side, to help test the theories presented below.

alignment-tracking.gif


This clearly shows that TOE IN is the front edge of the wheels, front being direction of travel, inclining towards the center line of the car.

Unfortuantly I can offer no explaination as to why this is named "IN" or positive

What I can do is try and explain the effects of having positive or negtive toe.

For this explaination, weight transfer must be realized, that is, that turning into a right hand corner, the outside wheels, the left, is doing all the work. This can be seen graphically by GT4 users, as you will experience nasty left hand side tyre wear while driving at Tokyo R246. This is due to 4 rather heavy G load tight hand bends. So, using this example, I claim that the outside tyre going into a corner, does the majority of the work.

With this in mind. Consider the effects of a car, with its front wheels set to a Toe IN position, ( according to my university notes positive ). This vehicle, approches a corner, and as it turns in, the outside wheel, is ALREADY pointing in the direction of the corner. So, using a right hand bend as an example, the left hand wheel is already pointing slightly right, and the right wheel is pointing the wrong way. This is where the weight transfer comes in. The effect of the right wheel is neglegable, as it is under far less load at speed, the outside wheel, doing the work, is turning the vehicle. The net effect, it would be expected, that the car is twitchy, and has a tendancy to "pin" and/or oversteer. ( pin to me, means the front will duck down violently on the side stated. ) The plus to that, is that a little Toe in, will help an FF or a 4WD car get its nose into the bends.

On the otherside, consider a vehicle with negative toe, or toe out. Approching the bend, the vehicle turns in, however this time, the outside working wheel is not already pointing the way it wishes to go, and the only wheel that is, is unable to effect the direction of the car significantly. The net result is understeer, although the car will be very forgiving, and not bite when turning in. Using this with FR or RR cars will dispell some of the nasty snap oversteer. Also, it makes a car that wonders around down the straight a little more easy to correct.

Thats the theory, however in practice, I ahev no clue what the PD programmers have done! I will give it a test and see, the b-spec pilot should be mister consistancey, and it should be evident while watching him drive, what effect +4 or -4 has on the vehicle. All I have to do is go prove it now! I would appeal to the more talented drivers to try the settings with a car they know well, and have set up exactly as they like it. Then make the radical change to the front, and see if the car understeers or oversteers, This should put to bed, if Toe IN is positive or negative on the game.
 
Nice, informative post cango_uk. Welcome to GTPlanet.

As I already believe, from my own (amateur) studies of suspension mechanics and racing tuning techniques, that TOE works in-game as you describe for real-life, I count as one of the "choir" on this matter.

That doesn't invalidate your input, however. It is always a bonus to have someone with the right qualfications posting on the GT forums 👍.
 
Hi, cango, and indeed welcome to GTPlanet. It's always great to see more and more quality thinkers signing up.

I'd like to counterpoint your post a little, however.
With this in mind. Consider the effects of a car, with its front wheels set to a Toe IN position, ( according to my university notes positive ). This vehicle, approches a corner, and as it turns in, the outside wheel, is ALREADY pointing in the direction of the corner. So, using a right hand bend as an example, the left hand wheel is already pointing slightly right, and the right wheel is pointing the wrong way. This is where the weight transfer comes in. The effect of the right wheel is neglegable, as it is under far less load at speed, the outside wheel, doing the work, is turning the vehicle. The net effect, it would be expected, that the car is twitchy, and has a tendancy to "pin" and/or oversteer. ( pin to me, means the front will duck down violently on the side stated. ) The plus to that, is that a little Toe in, will help an FF or a 4WD car get its nose into the bends.
Click to expand...
Toe in at the front of the car does work somewhat as you describe. It does tend to improve the overall grip and 'planted' stability of the nose as the car negotiates the turn, for the reasons you state: the more heavily loaded tire is biased toward the direction of the turn. This is also why you want toe out at the rear of an understeering car; in order to let the rear end caster around the corner better.

However, front toe in will not make the car twitchy or quick to turn in. In fact, quite the opposite.
On the otherside, consider a vehicle with negative toe, or toe out. Approching the bend, the vehicle turns in, however this time, the outside working wheel is not already pointing the way it wishes to go, and the only wheel that is, is unable to effect the direction of the car significantly. The net result is understeer, although the car will be very forgiving, and not bite when turning in. Using this with FR or RR cars will dispell some of the nasty snap oversteer. Also, it makes a car that wanders around down the straight a little more easy to correct.
Click to expand...
Unfortunately, this is not correct in theory or practice.

When a car has the front wheels set to toe OUT, it will be twitchy and responsive and have a much greater tendency to wander on the straights. Think of it this way:

When you steer the front wheels, they both turn in one direction. Now, since the inside front tire is approximately 6 feet / 2 metres closer to the radius point of the turn, it will be making a smaller circle than the outside front tire. If the wheels pivoted by the same number of degrees, the inside tire would be forced to scrub slightly. Engineers accomodate for this by designing the front suspension so that the inside wheel pivots farther than the outside wheel as you input more and more steering lock. This is called the Ackermann Effect. What is means is that in practice toe OUT increases as steering lock input increases.

Now, imagine a car that has static toe OUT in front as it drives down a straight. Since the wheels are already biased away from each other, any steering input at all in either direction instantly puts the car in an Ackermann Effect situation. In other words, even small inputs or differential loads on the tires themselves make it so that both front tires are describing concentric arcs. Any deviation from having the steering wheel straight ahead results in the front wheels being pointed for a turn. This makes the car twitchy and very quick to respond to intended turn-in, but it also makes the car unstable on the straights and tends to wander as the front tires are impacted individually by uneven road surfaces.

Once the car is settled into the turn, the cornering becomes steady state and the intended Ackermann toe compounds the static toe out. Consequently, the inside tire is excessively toed out and the car requires additional steering lock in order to override the outside front's static toe out and achieve the desired degree of pivot. This effect is as you describe in your post.

With toe IN at the front, however, the nose of the car is stabilized both on the straights and the corners, since the tires require relatively substantial steering lock input before the Ackermann Effect makes the tires describe concentric arcs.

Hope this helps.
 
I try my best fellas.

Duke, I reasoned it out in my head while getting though the daily grind, and i take your points on board. I reasoned with either toe in or toe out, the wheels were acting against each other, either trying to squash the chassis together, or trying to pull it appart. The point of this thread, I believe is to determine what + and - means on the set up screen, so a chief mechanic may employ the observations made above. Bottom line, what is extreme toe in going to do to the handling of a car, and what is extreme toe out going to do. According to my thinking, an extreme toe'd out car, will be solid and not wonder about down the straights. According to your thinking, it will wander around like robbie williams in a brothal... everywhere! I would like to get to the bottom of this, so that setting up is not so much os a suck it and see affair!
 
Well, the points I made about toe in and toe out are valid in the real world. I've found them to be generally true in the GT3/GT4 world as well, but the lack of subtle feedback (or any feedback) and the difficulty of the control systems make it easy for good or bad driving technique to mask the effects of suspension setup and alignment changes.

Good to have another voice in the discussion! See you on course.
 
regarding toe out and akkerman effect:

the issue gets further complicated by the fact that a tire produces its best grip with a slight slip angle.

As slip angle increases a few degrees, traction increases (the tire begins to howl a bit), and then at some point, the slip angle passes the 'optimum' point and traction falls off quickly.

The optimium slip angle increases as tireloading increases. So with 2,000 lbs of force crushing down on a tire, the tire's optimum slip angle at which it can produce the most lateral force is more then a lightly loaded tire with only a few hundred pounds on it.

In a sharp corner, the outside front tire has much more force on it then the inside front. This means that the outside front makes its best traction at a relatively high slip angle (again, we're only talking about a few degrees, or fractions of a degree), compared to the inside front which makes its best traction at a low angle of attack.

From this, one might think that having 0 toe, and no akkerman effect, would be ideal. The more the wheels turned, the more of a difference in slip angle exists... that is assuming that the front tires optimum slip angle is large enough, and the radius of the turn large enough, that the inside front was at a smaller slip angle, but to the proper side.

What this really underlines is that the front alignment and steering rack geometry is an incredibly complex system, and the fact that we have an 8-position slider to adjust one variable makes a lot of this a moot point.

Here are some pictures to illistrate my point.

in one, there is a comparision of 0 toe 0 zero akkerman, vs. 0 toe and normal akkerman. with that radius turn, at that speed, at that weight, and that tire, 0 toe & 0 akkerman is ideal, or whatever combo of toe & akkerman results in that alignment. (maybe normal akkerman & toe in? so that at that particular angle of steering deflection, the wheels are at the angle?)

in the other, it shows how 0 toe & 0 akkerman is NOT the same, because of some change of one of the many variables.

This simply underlines how incredibly difficult the chassis engineer's job is.

NOTE: ALTHOUGH I DIDN'T PUT THE FOOTNOTE IN BOTH, THE DEPICTED ANGLES ARE EXAGERATED
 

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Could someone clear this up for me?

I know what toe angle is, no problem there.


What I need to know is what constitues postive and negative toe on the PAL version of GT4. what i want to achieve is this...

Front: / \

Rear: \ /

What I need to know is whether o put + or - values in to achieve this toe alignment?
could someone respond simply with...

Front: / \ requires a [ - or + ]

Rear: \ / requires a [ - or + ]

A the moment I'm assuming it requires + at the front and - at the rear (as the F1 is set up with - at the rear). Any definative clarification would be greatly appreciated!
 
As far as everything I know and believe, you are correct in what you're assuming:

+ = toe in
- = toe out
 
cango_uk
I try my best fellas.

Duke, I reasoned it out in my head while getting though the daily grind, and i take your points on board. I reasoned with either toe in or toe out, the wheels were acting against each other, either trying to squash the chassis together, or trying to pull it appart. The point of this thread, I believe is to determine what + and - means on the set up screen, so a chief mechanic may employ the observations made above. Bottom line, what is extreme toe in going to do to the handling of a car, and what is extreme toe out going to do. According to my thinking, an extreme toe'd out car, will be solid and not wonder about down the straights. According to your thinking, it will wander around like robbie williams in a brothal... everywhere! I would like to get to the bottom of this, so that setting up is not so much os a suck it and see affair!
Click to expand...

I race both an ITB Fiero and a Spec Miata in SCCA and NASA competition, and I can definitely say that toe out of the front tires will help turn in, and make the car MORE PRONE to wander on the straights. It has more to do with road surface than anything else though. A nice smooth track, and you'll hardly notice. A track with a lot of crown, bumps or grooves, and you'll notice.
 
I played with my Pontiac GTO in the game last night some more...

I 100% agree with ZOOMZOOM's findings for the rear toe. a positive number is toe out.

FRONT

|=====|


\=====/ = a positve number

REAR
 
ok so, since there is still no definite answer... has anyone tried getting an open wheel car and putting the front camber to an extreme angle and then tried looking at the wheels durring gameplay? I'm going to try this tonight, because I know that when you adjust the C 👍 :sly: amber you can definitely notice if your tires are like / or like \ So you should be able to notice with the Toe also... try cars such as the polyphony digital f1 car... or anything else open wheeled.
 
I'm awfully convinced that "-" is toe-in and "+" is toe-out in both front & rear...

Some cars I can make "big" adjustments and find very little difference.
 
ok the verdict is in, using the polyphony digital f1 car in GT4 I set the front toe to -6 and the default suspension setting for the toe in the rear is set at -6 already. I switched to the front wheel view, the tires were as shown \^/ The tires are clearly seen to be angled, try it yourself.. So that being said, - is toe OUT \ / and + is toe IN / \ makes sense right? I couldnt really tell the back wheels that well. But I'm almost positive its the same thing. Which would make more sense in a f1 car, -6 toe in or -6 toe out. This is the default setting already on the car.
👍
 
Did you try setting the front wheels to +6 and see if it made a difference?
 
May 24 2005, 10:54 PM Post #89
toe in for front and rear, / \ , toe out for front and rear, \ /. at least in real life its that way
Last edited by billdo : May 24 2005 at 11:12 PM.
Click to expand...

;) ;) That's the way i see it . Toe out the rear for a ground pinioned midshipper . Toe in the front to quell oversteer through chicanes etc with big frontrear.
:odd: :odd: You apparently adjust the toe in the photo mode but it looks like camber to me Anyone else get visual confirmation of these wheel angle settings ?
 

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