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If we assume the pivot point is centred between the front tires the amount of toe-in to cause the tire to try to go towards the opposite side when it has more grip would be extremely noticeable. It would require the tire to be pointing past that centre point. Therefore the car will always rotate to the side with the most grip. Once rotated part of the force pushing the car forward is now perpendicular to the direction of travel, this happens regardless to the toe angle.

Now imagine that rotation with toe angle, one side the tire lines up better with the direction of travel while the other is even further out of line of travel, but pointed in the direction required for correction (0 toe angle both would be the same). If you were to add up all the forces pushing for correction they are the same no matter what toe angle you have. So why is toe in better? Because the tire with most grip is providing more of the corrective force as it is the tire with the most force. If neither tire has more grip than toe angle wouldn't matter.

To put some exaggerated numbers to it. One set-up has 0 toe angle, so each rear wheels provide 50% of the force to move the vehicle forward, and have 0% side force. The other set-up has toe angle that provides 40% of the force moving the car forward and 10% of the totals force sideways. Each tires side force cancel each other out and we end up with 80% efficiency in our forward direction. For now toe-in or out does not matter.

Now our cars get rotated while driving and need to correct. The first example rotates to the point where the tires are now providing 40% forward and 10% side force. The total being 80% forward and 20% to the side for correction.
The other car rotates the same amount, now one tire is pushing forward 50% and 0% to the side and the other is 30% forward and 20% to the side, or a total 80% forward and 20% in the direction of correction.

At this point it looks like toe angle is just bad as it just robs forward power. But the side that has rotated forward is also the side with the most grip (what caused the rotation to begin with) so let's throw some more numbers in! Let's say grip is now 25% on the loose side and 75% on the other. The first example has one side pushing 20% forward and 5% in a corrective direction and 60% forward and 15% to the side. The total is the same 80/20 split.

With toe angle one side is now pushing forward 25% and the other is 45% forward and 30% to the corrective side or a total of 70% forward and 30% corrective. This extra corrective force is what causes the improved stabilisation at the cost of forward power.

Like I said all these numbers are somewhat exaggerated and generalized to try to explain what I mean. Personally I think toe angles should be adjusted more for other uses than for stability; stability can be improved with other methods that have less negative effects. Example: rear down force drag has less negative effects at low speeds than toe angle while still providing high speed stability when it is needed. Of course toe angle is sometimes our only choice.

I hope I explained myself well enough and keep up the informative posts!

I think this post came in while you were typing BUT I Still need to read through your post (your explanations are great) I still need to take my time reading then to be sure I get all they contain.

I dunno, looking into it further looking for where its wrong but I cant find anything. I did find some info on the subject though

"" Toe in causes a condition where each wheel individually attempts to align itself straight forward. As each wheel aligns itself straight, the opposite wheel assumes all of the toe value. As the wheels alternate between straight and toe in positions, the steering linkage and steering wheel oscillate back and forth creating a shimmy. Toe in tends to equalize between the two sides rather than oscillate. As in if you have more toe in on the right then the left, the two will centre each other and the steering wheel will centre slightly to the right, thus equalizing the amount of toe in between the two tires.

As far as handling, toe in tends to make that end of the car more stable. As in it wants to keep going in a straight line more. Reason being is the thrust vector (the rolling direction of each tire) is pointed towards the centre of the car, so the two tires fight each others path of motion.

Toe out each wheel will roll in opposite directions and neither can find a straight position. The result is a car that seems to require constant steering input to keep travelling straight forward.

[This next part is important here]

Toe out will also Equalize between the two tires, much like toe in. However, handling wise toe out will tend to make that end of the car more unstable as the thrust vectors of the tires are pointed away from each other."""

The pic simplifies this visually IMO and I don't see where its wrong. I want to give you the benifit of the doubt because you seem to have a better knowledge of physics and I only focus on vehicle specific.

The problem is a misunderstanding of thrust or vectors or something. This person also thinks the trust vector is in the direction of the rolling tire when it is in fact the opposite of that. Forward movement of the car is the reaction to the thrust. He also states toe out 'equalizes' yet then tries to say it is because they are pointing out, so which is it? If you have two tires pulling in opposite directions and that causes the stabilization what difference does the side of the car each are on? One pulls left and the other pulls right in both cases. Unless it is something else. (See earlier post)

You have to total both tires thrust, swapping the tire sides (or reversing the toe angles) result in the same total thrust and vectors as they are both connected to the same object, pointing in or out just changes the amount of thrust that is put into moving the car forward and how much is being cancelled out by the opposing thrust. Looking at the one wheel at a time results in the wrong conclusion.

(Note: before we get into conservation of matter/energy the thrust is not actually cancelled out but transferred to the chassis in the form of compression and transferred back to wheels causing the slippage to convert it to heat on the tires)

And it not that someone's common sense is wrong but that we as people see things with our intuition and accept that as correct. Intuition tells us that the tires are moving in that direction and if they would collide they would result in motion we see as a result of the toe in. I can see that as an intuitive answer, but I know that it is wrong.

The same sort of stabilisation is used in aviation when dihedral is used in wings to correct to level flight. Total lift is sacrificed for stability in that case. But there is less misinformation about that.(I hope)

Area Motorsport UK
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AREA Motorsport is a UK shop, they have a good reputation, they are in the business.

I'm not saying their word is gold, but I feel it is a quality source, and falls in line with every other performance suspension specialist I've seen over the years. While I get what your saying my understanding falls more aligned (wrong or right) with these guys. I'm looking for any source materiel saying otherwise but I can't find any.

The GTP Tuning Guru says unless you had camber set pre 1.09 the car will be unaffected by the physics change, and if using camber pre 1.09 then major work needs to be done on the set up to have it perform as it did pre 1.09.

Dolhaus says:

""The cars should be unaffected unless they were using pre-patch camber to dampen front end transfer (reducing front grip to make a car less aggressive) or using rear camber to allow for faster rotation.""

SiNiST3R Says: BULLSHIT!!!!

Ive not changed my pre 1.09 camber settings on any car, all my tunes built pre 1.09 with camber are running beautifully, my tweaks for adapting to the new physics has only involved rear toe, downforce and differential settings. My springs dampers and wheel angles (aside from rear toe) have not been touched. I have many cars that hot lap identically pre and post 1.09 not just in lap times but in Datalogger analysis also.

I see pretty much everybody who was running Zero Camber set ups scrambling to retune scratching their heads. The NASCAR crowd especially, many of them are dogging the new physics because the "awesome" set ups they were running all drive like shit post 1.09

But you know the GTP Tuning Guru didn't use camber, had only Zero camber set ups pre 1.09 so he should know right.. Yeah right...

IMO if you were running Zero camber pre 1.09 YOU need to start adding some and retune if you want great performance in 1.09. PD is and most likely will continue to work at making proper tuning work and killing exploit tuning (like zero camber) Zero camber exploited the lack of detrimental effects of zero camber, PD Fixed this with 1.09. Camber well tuned pre 1.09 is still good (if tuned well) in 1.09.

Nice, while cars tuned with camber pre 1.09 at GTP are scarce not many with more than 0.5 of an angle. Ive already seen my cars tuned with camber before 1.09 working just fine since 1.09 but Its nice to see a GTP car that was tuned with camber before 1.09 also working well since 1.09.

Ive not driven it, but its getting commented on in the GTP camber thread.

What I dont understand is the logic being used. When Buddy says tunes don't need any changes unless the were tuned with camber. Its more like the exact opposite. Ive been enjoying my cars since 1.09 and tested many cars of various drivetrains, power etc all still using the same camber angles, adjusting for new dynamics has consisted of downforce rear toe and diff settings. I see GTP scrambling since 1.09 most complaining the zero camber tunes no longer handle well at all. I believe they lost the benefit from exploiting the lack of grip loss in dynamic positive camber. 1.09 PD has fixed this and now positive camber dynamically kills grip, now zero camber tunes are all shit. Thanks PD.

More WARNINGS be careful of what is said at GTP. They get on some weird trips and seriously overcomplicate things. Oh and yes Im calling out Names of GTP members who talk shit. They are more than welcome to come here and defend themselves, a luxury I don't have at GTP so fuck them

Bowtie Muscle another GTP Tuner who has had my name in his mouth is talking some serious stupid shit.

Hes claiming while the new physics help cars with independent suspensions, hes saying cars with solid axle rear ends don't benefit from any rear end camber.

What?!?!?

Since when has a solid axle rear end been in Gran Turismo? Its something I though was common knowledge that all suspensions in GT, stock or adjustable are ALL fully independent suspensions.

It should be common knowledge because its so damn easy to check. Solid axles will have absolutely zero camber gain as the suspension is loaded and unloaded. So get some air and look at the wheels. In the air positive camber gain and when compressed on landing, negative camber gain :O

This guys saying his Camaro SS '00 in GT6 has a solid axle rear end. He should take his own advice and recognize there is a difference between real life and GT. In the real world the car may have a solid rear axle but not in GT6. Just to be sure 1.09 didn't have me eating my words with a stealth addition of solid axle rear ends I bought a Camaro SS '00 to check. Sure enough, get some air and see the positive camber, scope the landing and while loaded negative camber gain, both with stock and adjustable suspensions. This confirms the Camaro SS he's claiming has a solid rear axle in fact has a fully independent suspension, pissing on his stupid ass theory.

What I really don't't get is why nobody is correcting him. It should be common knowledge, I even have a video posted specifically on the subject (its on page 1 of this thread) showing not only do cars all have independent rear suspensions, but also showing the camber gain from car to car is the same. In reality all cars should have a different amount depending on the geometry and design of the suspension. This doesn't really matter so long as all cars perform correctly as if a custom or independent suspension upgrade has been done. Coil-Over conversions are often done on these cars to benefit from modern suspensions (fuck its not even really "modern" anymore) more like ditch the almost Jurassic old ass suspension lol.

How on earth something so basic is flying over the heads at GTP I do not know.

One thing that is good is since the update is much more people are getting in on the subject so the views are not as singular as before. People are voicing opinions without worry of some idiots arguing in circles.

EDIT

He got partially corrected, another member says when adding an adjustable suspension the live axle gets a coil over conversion..... I say partially because while yes the adjustable suspension is independent, there is no conversion from a solid axle, the suspension is always fully independent.

So Bowtie is saying PD gives some cars extra love but they must not like the Camaro SS '00. I don't get it, the car took all of a hour or so for me to Tune a moderate 525pp SS set up that carves corners. Running modest 2.5/2.0 negative camber angles. Eiger Nordwand in 1:09 for update 1.09 lol. Not a record breaking lap, but decent for a quick tune and lap session of only an hour and as always all assist turned off no ABS.

PD likes my Camaro SS '00

Got to say Im liking this Kat from GTP 332i, the guy is on point and makes for a good read and should be informative. Hes a lil stuck with a few members who are overplaying a bad hand, can't help but relate lol