The Art of Setup Building, Part 2: Your best friends

The tires, temperatures, pressures and alignments.

You might have heard, a lot of times in fact, that the tires are the only part of the car that's in contact with the road. While not always true (though you generally don't want the floor touching the ground too often), what is true is that adjustment to the tires can net so much more time than nearly any other adjustment you can make. Before we get into that, however, we need to look at the rubbers themselves first.

The compound

In F1C, the tire suppliers give us 2 different compounds of dry weather tires, and 3 different configurations of wet weather tire. For now, we'll focus on the dry tires and leave the wets to the Rain Adjustment section. Naturally, the compounds can change when mods come into play.

The two tire compounds we have are the Soft tires and the Hard tires. Soft tires provide excellent grip and are quick to heat up, which makes them ideal on races in cold weather. However, their wear rate is high and they can quickly overheat in hot weather or tracks that put a lot of stress on them, tracks that have lots of high speed corners can destroy them. 

Hard tires work the other way around. They are considerably more durable than the Soft tires, and are more resistant to stress and temperatures, making them ideal for high stress tracks and high temperature. The cost is that they generally lack grip, specially at low temperatures. They also take a while heating up.

Generally speaking, in F1C, there's not much need to use the Hard tires. The Softs are fairly durable, and a slightly overheated Soft often times has more grip than a properly heated Hard. Hard are more useful when planning a race strategy. A Hard tire, 1 stop strategy can be faster than a Soft tire, 2 stop strategy if the Softs heavily overheat and the Hards don't.

For the purpose of our exercise, we will use the Soft compound, the same compound we used on the last practice session.

Temperatures

OK, we have selected a tire ... however, right now we don't know a lot about it. If anything, we need to know the optimal temperature at which the tire provides maximum grip. Different sims have different ways to show this. gMotor powered games like F1C have a tire file, in this case a .tbc files, that contains all information regarding the tire compounds. Characteristics like grip level, optimal temperature and pressure, camber angles, rolling resistance, etc. Right now, we want 2 of those characteristics, optimal temperature and ideal camber angle. Opening the SeasonData/Vehicles folder lets's me see many files, among them the .tbc files for every season. I opened the 2001 Michelin tbc file and found this.

Those are the characteristics of both front and rear Soft Compound tires we are using, the 2001 Michelins. The important information for us are the OptimumTemp line and the CamberLatLong line. OptimumTemp tells us that the ideal temperature for this tire is 113ºC, both front and rear. CamberLatLong tells us that the ideal camber angle for maximum grip is 2.99º at the front and 2.07º at the rear. Remember those values, they'll be relevant later.

So, right before we start FP2, we need to know what kind of temperatures our tires were hitting. Fortunately, the telemetry tool can show us this information. Ideally you run at least 4 laps before considering this information relevant. Remember that tires take a while to heat up and get up to pressure. I loaded up the last stint done on FP1.

The red line is our fastest lap, the blue line is the stint's last lap, generally the most relevant. Doesn't matter, both are on average well over 10º over target, and more than 20º over target at their most stressed. While the right front looks fine, the rest of the tires are cooked. This might explain why we are slow, we lack grip due to the tires being too hot. 

The problem arises due to the fact that, directly, there's no way to lower tire temperatures, at least not with setup changes. You can change them indirectly using some of the adjustments to be shown later in this post, and in other posts. However, the best way to alter and control tire temps will always be the driver. Slower, more controlled inputs will help diminish temps. Lower steering demand will lower front tire temperatures, softer throttle application will lower rear tire temperatures. Me, being a keyboard pleb, can't really put those tricks into effect without sacrificing performance, but wheel/pedal users have an extra weapon at their disposal.

Summary

• Through out the setup process, you need to keep track of the tire temperature, both average and maximum, as they'll be able to inform you of potential handling issues and setup problems.
• Keep in mind that track characteristics and you, the driver, have a massive influence over the tire temperatures, most notably overheating.
  

Pressures

OK, we now know that the tires aren't doing great in terms of temperature. This tells us there's some kind of issue somewhere in this setup. Let's start with the easy, are the tire pressures right? I will focus on the setup itself and talk about what tire pressure are, what they do to the tire and what they do to the setup/handling in detail in the final section of the post, for now we'll focus on the data we have. The last telemetry chart we saw showed us the tire temperature through the lap, the F1C telemetry tool can also show us metrics that we can use to evaluate tire pressures and alignment.

Again, red line is the fastest lap, blue line is the last lap of the stint. We are going to focus on the first 4 charts, the Tire Crown Temp charts. The ideal would be close to 0. Every tire except the front right is WAAAAY over pressure, as the lap lines are well over 0. While there are benefits to high pressure tires, this is excessive. We need to do something about it. We must visit the Tire Pressure and Camber page.

In this page we have the Starting Tire Pressure, Static Camber Angle, Static Toe In Angle and Selected Compound. We also have a Symmetrical selector. If set to Yes, any adjustments we do on the left side will also be applied to the right side.

In this case, we will focus on the Tire Pressures. A good rule of thumb is to, after reading the Tire Crown Temp chart, lower the pressure by about half of the Max Value. For the front, I'd lower the pressure by about 9 clicks, the rear by 6 clicks. I decided to make the pressures symmetrical. After changing pressures, this is how the screen looked like.

Less pressure overall, which looks good. I gave it a few laps. Remember, after any tire adjustment, you must run at least 4 laps to get any sort of consistent data. After those laps, I opened the telemetry tool.

Yellow is the last lap, green is the best lap. We must focus on the yellow here. The tires are now closer to the 0 line. The right front and left rear are under pressured, we just add a few kPa to them to get them closer. The car itself felt much better. I felt I had more grip, specially rear grip and low speed. It wasn't a lot more, but our current fastest lap is 1:23.059, an improvement of a tenth and a car that feels better under my control.

Yep, the delta shows that it was in Sector 3 I gained that extra tenth, while the rest of the lap was nearly equal to the reference lap, our fastest lap from FP1. Tire pressures are pretty good right now.

A suggestion, don't focus too much on getting the Tire Crown Temp at exactly 0. You have a decently wide range of useful pressures. Your pressures should be fine as long as they are between 5 and -5.

Summary

• For the optimal combination of handling and grip at different speeds, alter the tire pressures until the Tire Crown Temp is close to 0.
• There's more to it than that, details on a later section.
   

Camber Angle

OK, we now have the tire inflated optimally. Next, we are going to maximize the grip they can provide us. Once again, the details of why this work will be left for later, for now we'll focus on the setup adjustments. Let's go back to the Tire Pressure and Camber screen.

Here we can see the adjusted pressures I gave the car. We focus now on the Camber. A while ago I asked you to remember the ideal Camber angles as seen on the .tbc, as we'll use them here. 2.99º Front, 2.07º Rear. Since we can't use settings with 2 decimal numbers here, we will simply round up and input the setting as a negative number (Positive camber is useless on road course racing).

With camber now set up, we take the car to the track. On track, the car felts as if it had much, much more grip. The car turned in more easily, yet didn't feel loose or about to break into oversteer. It just had considerably much more lateral grip. While camber reduces longitudinal grip (acceleration and braking), I didn't feel that much different. The car outright had more grip and could corner faster. But how much that affects the lap time?

It does significantly.

1:22.486. A gain of 6 tenths of a second over our previous setup, and 9 tenths quicker than the default setup. This is how much grip a properly set up tire gives us. Remember, I said there were about 1 to 1,5 secs still to find. We found 0.9 secs as of now.

The red lap is the last lap of the stint, I spun on the final corner complex because I got distracted. The green is the previous best, without altering the camber. You might notice that generally, the red lap has lower pressures than the green lap. That's because, after adding camber, the tire is now gripping more and sliding less. Less sliding means there's less heat, means lower tire temps, means lower tire pressures. While we do any kind of adjustments, keep an eye on the temps and pressures. Chances are you'll need to alter them by a click or 2.

Do be aware that the camber we gave the setup is, what I think, is the minimal camber that should be on any setup. You can get a bit more lateral grip by adding a few extra ticks of camber, and I'll do so.

To close this section, Camber is usually a set and forget setting. You set it and don't touch it again for the rest of the going. 

Summary

• Increasing negative Camber will increase lateral grip, allowing higher speeds to be taken into corners. Don't overdo it, however. While tire wear and temperature might be affected, the effect isn't always negative.
  

Toe Angles

We got the tire properly inflated, it has extra grip thanks to the camber angle adjustments. Now we can start tweaking the behavior of the car with toe adjustments. Back to the screen.

Here we can see the adjusted pressures and camber angles. I also adjusted the Toe In Angles. Typically an F1 car will have Negative Toe (Toe Out) at the front, and Positive Toe (Toe In) at the rear. I made the obvious call at the rear, as that as stability under throttle and against bumps. At the front, I went opposite, adding Positive Toe for extra stability over curbs. Again, I'll give more detail later.

I gave this setup a run. The extra camber gave me more grip, as expected. The Toe Angles made the car more stable over curbs, a little issue I was having with the previous setup. I could now run a bit more over the Magotts-Becketts curbs with more confidence, as well as be on the throttle earlier in the final sector,

A new fastest lap of 1:22.137, along with multiple laps all faster than my previous PB, show that the setup has developed a lot.

Summary

• Use Front Toe to adjust turn in behavior, as well as behavior over curbs. Toe In adds stability, Toe Out adds responsiveness. This only works during turn in, it doesn't do much mid corner. This is very simplified.
  
• Use Rear Toe to adjust rear stability. Toe In adds stability, Toe Out adds rotation. Toe Out is a high risk, high reward setting to use, I don't recommend. Rear toe affects the car nearly all the time.
• Don't overdo Toe if it isn't necessary. Temp, wear and speed can be sacrificed.
  

All of this was done in 30 minutes of FP2, and we smashed both Irvine and the Saubers, the fastest lap on that group being a 1:22.156. As we enter FP3 and FP4 this will change, but for now this setup is working really well, and there are more improvements along the way, I still have 30 minutes of run time. There's a pair of adjustments I can do and test in 30 minutes.

Time Summary

Starting Lap Time: 1:23.342
Laptime after FP1: 1:23.154 (-0.188)

Laptime after tire adjustments: 1:22.137 (-1.017)
Expected Lap Time: 1:22.272 (+1.070 compared to start, -0.135 compared to finish)

Why all of this works?

This next part is completely optional. Like I said quite a few times before, I'm going to explain why the setup changes work the way they do, what kind of effects they have on the car, and what kind of things can be improvised with them. It is a bit more sciency, as I (try to) explain the physics behind each setup setting. If you just want a rundown of what each setting does, just scroll down to the summary of each section. If you want to know why things work the way they do, read on.

Pressure

As you know, and if you didn't I present you this fact, tires are made out of rubber. Rubber is sticky and flexible, which makes it ideal for tires. This rubber, while durable, gets completely destroyed at the pace F1 cars drive at. Even when stationary, the tire without any assistance would get squished and the car would rest on the rim or the car's floor. You can't drive around like that. Even if you could, only the sides of the tire would be in contact with the road, which is a waste of resources when the tire is as big and wide as an F1 tire. 

The tire needs help, and that's why we fill tires with a gas. The gas helps it maintain the round form that we desperately want it to have, and adds some stiffness to it. It won't collapse under load, while remaining sticky.

So that means low pressures are bad. That means we need to put a lot of air on the tire, right?

Nope. As you keep filling up the tire more and more, it does two things:

1. It gets rounder. The center of the tire starts to bulge, which reduces how much tire is in contact with the road. And less contact with the road, among other things, means less grip.
2. It gets less flexible. While it is nice that it holds its shape, a tire that doesn't flex doesn't have as much grip as it used to have when it was more flexible. Less flexibility, among other things, means less grip. 

So, we can't have too much pressure, and we can't have too little pressure ... what do we do? We reach a middle point. Generally there are 2 ways of finding the ideal pressure for a racing tire. Either the manufacturer gives it to you, the route sims like AC and Project Cars 2 took, or you use tire temperature data to find the right pressure. This is the route gMotor powered sims like rFactor, AMS and, of course, F1C took.

The ideal pressure is obtained by iteration, you repeat a process until you find the ideal point:

1. The driver gets the car out on track, does a series of laps at racing speed (Race pace, people, not hot lap pace) and brings the car back into the pits. About 4 straight laps at racing speeds are enough. Ideally, these laps don't contain any rallying excursions or spins. This might screw the results and the laps might have to be done again.
2. Now on the pits, the engineer checks the telemetry. They want to check the difference between the Inside and Outside of the tire, and the Middle section. We know this in F1C as the Tire Crown Temp. They will check this telemetry channel, suggest a tire pressure adjustment and send the car out on track again, just like in step 1. They will keep in mind that each tire needs a different adjustment.
   
3. This process is repeated until the Tire Crown Temp channel value is at, or very close to, 0. At this point, they know they have found the ideal tire pressure ... for this track, tire compound, immediate car setup, driver and track conditions.
4. Since any of the previously mentioned components might change during the session (specially setup and track conditions), the engineer will keep an eye on the Tire Crown Temp channel after every run and suggest changes if needed. These changes shouldn't be bigger than 1 or 2 kPa, however.

This procedure optimizes the tire pressures around the lap. However, that isn't the end of the story. While we have an ideal tire pressure optimized for the whole lap, it is never perfect for ANY corner on the race track.

You see, there isn't one ideal tire pressure for maximum grip. There's an infinite amount of ideal pressures, one for every moment on track. The ideal pressure varies with load. You put more load on the tire, and you need more pressure to keep it perfectly round and flat on the track. By logic, if the tire pressure is optimized for a low speed corner, the moment we attack a high speed corner with all the downforce in the world pushing down on the car, the tire will flex too much and the middle of the tire will stop touching the road. We'll lack grip, and the tire will overheat. Similarly, if we optimize the pressures for high speed corners, the tire will bulge and not flex enough when we deal with a slow corner. We'll lack grip. Not only that, but this doesn't take into account the straights where the car is exposed to high loads without doing much.

With that in mind, the general consensus is that you'd rather run a tire slightly under-pressured, since that allows a bit of flexing of the tire and allows it to grip a bit better, than a slightly over-pressured tire. Remember, only slightly. When I build setups, I range my pressures from -5 to 5 at most. Anything more, and you are sacrificing too much grip.

That isn't all however. Over-pressured tires hold a pair of advantages. You might have heard that stiffer suspensions react quicker? The same happens with tires with high pressure, as they are stiffer and will only flex a bit before starting a reaction. In comparison, under-pressured tires will take a bit more time to flex and do what its asked of them. For the same reason, slightly over-pressured tires will heat up less and wear out slower.

Now, this varies from sim to sim. In gMotor powered games, a tire heats up due to being in contact with (and being squished into) the road, and due to being sliding on the road. A slightly over-pressured tire will reduce the first aspect (more stiff = less flex = less rolling heat) while barely moving the needle on the second one. A slightly under-pressured tire will increase the first aspect. This reduced flexing is also the reason why slightly over-pressured tires will wear out slower than under-pressured tires.

Finally, there's rolling resistance. Basically, the more flex a tire has, the stickier it becomes while rolling on a road. This means that an under-pressured tire will be harder to roll forward than an over-pressured tired, the under-pressured tire will be gripping the road more than the over-pressured tire. The result is that the under-pressured car will have poorer acceleration, top speed and fuel consumption compared to the over-pressured car.

You need to take all of these aspects into account when selecting a tire pressure. You can just take the ideal tire pressure by making the Tyre Crown Temp channel 0, that's perfectly fine and works on any track. But you can still extract a bit of extra performance out of the rubbers by altering the pressure slightly from the ideal. Me, I tend to drop the pressure 1 or 2 kPa, while lap times don't necessarily improve, I feel more confident in the car. You will heard this advice a lot, but do what works best for you.

Summary

• We want to find the ideal tire pressure for every tire, as that gives a solid mix between grip at low and high speeds, response, heat and wear.
• A slightly over-pressured tire will exhibit a quicker response, increased performance during high speed maneuvers, reduced heat, wear and rolling resistance. It, however, loses performance during low speed corners and overall grip is lower.
• A slightly under-pressured tire will exhibit higher grip and increased performance at low speed. It suffers from increased wear, heat, rolling resistance and reduced high speed performance. The additional flexing and grip might nullify the reduction in raw high speed performance, however.
• Deviating too much from the ideal will exaggerate the negative effects while diminishing or eliminating the positives.
• Tire pressure are NOT to be used to balance the car, unless desperation has set in. There are better tools for the job.
  
• If in doubt, stick to the ideal tire pressure. 

Camber

Unless the tire is attached to an infinitely stiff suspension system (or active suspension), the car will exhibit roll when we take a corner, and the tire will follow along with it. That means that, if the tire was directly upright, which is what logic would tell us would be better for grip, it is now going to be at an angle relative to the track. We'd been fighting hard with the pressures to get the tire to be flat on the surface, and now taking a corner will undo that job. 

That's why F1 teams don't run zero or neutral camber. They run negative camber. Negative camber tilts the top of the tires towards the middle of the car, while the bottom of the tires tilts to the opposite way. The idea is that, while cornering, the outside tire (which is the tire with more load during cornering) will return to being upright, completely flat over the road and offer more grip. Not only that, but a cambered tire will try to pull to the side towards it is cambered. A pair of negatively cambered tires will create an inwards pull. This is called "Camber Thrust". This means that, as you start turning in, the outside tire will pull the car into the corner harder than usual.

However, remember what we talked about in during the pressure section? Tires flex, and this flex will occur during cornering as well. If we just camber the tire to be upright during cornering, the tire will flex and the effect of the camber angle will be diminished. This is not what we want. Additionally, we want to take advantage of the Camber Thrust to increase our cornering grip.

Tire suppliers generally provide to the teams the camber angle at which the tire produces maximum camber thrust. If they don't then teams can test until they have a value. Thanks to the gMotor engine being simple enough, it is easy enough to look at the .tbc tire files and look for the CamberLatLong line. The first value defines the ideal Camber angle, the second value defines the increase in lateral grip at this angle (our Camber Thrust effect), the third value defines the loss of longitudinal grip if the car had a camber angle of 90º relative to the ground.

Now that we have our ideal camber angle, we get to work:

1. The car setup is assigned the ideal camber angles and it's sent out on track. Like with the tire pressure setting, the driver must put at least 4 racing speed laps without spins or rallying to get good enough data to analyze.
2. The engineer will now look at the difference between the Inside and Outside temperature of each tire. This is called Tire Camber Temp on the F1C telemetry tool. Tires and sims will make this rule vary, but the engineer expects to see a difference between 20º and 25ºC at the front, and 10º to 20º at the rear. Excessive temperature splits will be controlled with a reduction of negative camber. Small splits will be handled by an increase of negative camber.
3. After the adjustments have been applied, the driver will repeat step 1. With the ideal camber angles as a starting point, this shouldn't take more than 2 or 3 runs. 

This procedure optimizes the camber angles around the lap. And while that isn't the end of the story, we don't need to optimize the camber angle for a specific corner, settle down.

First, using the Tire Camber Temp channel relies on the tire pressure being close to optimal. Otherwise the Camber temperature values will be screwed. Get your tire up to pressure first.

The first proper issue comes from what camber does to the tire down the straights. Since the tire is at an angle going down the straights, the inside part of the tire will have to deal with more load longitudinally. In other words, you will lose some braking ability and traction. However, the gain in lateral grip more than makes up for that. If you still aren't confident, make sure the Tire Camber Temp channel is towards the low end of the range.

The second issue is temperature and wear. The inside part of the tire now has more responsibilities, which means it will heat up more, and will wear more than the rest of the tire. While this is notable, often times a properly cambered tire will be cooler and last longer than a tire that's more upright. The reason is the increase in lateral grip. More grip leads to the tire sliding less on the road. Less sliding means the tire doesn't heat up as much and that it doesn't wear as quick, plus the fact that a cooler tire wears slower.

The final issue is when Camber Thrust turns against us. If the setup is not properly adjusted, going over a curb or hitting a bump will unsettle the car. This is very notable if one of the wheels lifts off of the ground. Usually, camber thrust nullifies itself down the straight because the tires counter each other. The moment a tire lifts, the pair of forces turns into a single force that wants to pull the car into a direction you might not want to. While this has benefits (lifting the left front into Monaco's Hairpin isn't so bad), it can be difficult to control in bumpy tracks or tracks where curb riding is needed. Imola and Magny Cours come to mind. Fortunately, we have a setup adjustment that can deal with that.

There's not much else to camber TBH. I generally set this during the first few runs, and don't touch it again during the setup building process.

Summary

• The ideal Camber angle is very easy to find, as the .tbc file gives you a value close to the optimal.
• Higher camber values will increase cornering grip substantially, for a penalty on acceleration and braking. The additional grip is likely to improve tire wear and reduce temperatures
  
• Lower camber values will reduce corner grip, but will make it easier to find straight line grip, ideal for acceleration and braking.
• Excessively high camber angles will start reducing cornering grip. This will start increasing tire wear and temperatures for no benefit at all.
• While lower camber values can be used, the gains of high camber value is too good to pass up. An improvement of at least half tenth is expected on many tracks, although more than that is more than likely.
• We are dealing with road course racing, positive camber is not to be considered.
• If in doubt, stick to the camber angles in the .tbc files and add 0.2 to the value.
  

Toe Angles

Logic would tell us that we want the tires pointed directly towards where we want to go. Through the course of these sections, you might have realized that common sense and logic does not apply to race car setup. This is a subject that I'm not 100% sure on, but I'll take a stab at explaining it. For a tire to provide grip, it must slip over the surface. Do be aware that this is "slip", not "slide". Under acceleration, a tiny bit of slip will give more acceleration and deceleration force. This is achieved by the tire rotating a bit faster than it should under acceleration, and rotating a bit slower than it should under braking. Just a bit, not enough to generate smoke. During corners, a little slip will increase cornering force. For this to happen, while the car is travelling at a certain angle, the tire will be pointed in slightly more aggressively. The difference between the car's travel direction and the tire's angle is called "Slip Angle". Excessive slip angle will create sliding and extra heat. Just enough will create extra cornering force.

So, we know that we need some slip for the tires to create force. If the tires are pointed directly straight, they will only generate cornering force when we turn the car. This slows response and diminishes grip. With that in mind, we can alter the static angle the tires hold relative to the road. This is called Toe angle. We need to subdivide this into front and rear toe, simply because they affect the car in different ways.

Front Toe: Adjusting Corner Entry

Unless your car is weird like that, the front tires are responsible for generating the cornering force that will get your car into the corners. With that in mind, changes to the static Toe angle on the front tires has an effect on the car's entry into corners. 

General consensus is that Toe Out, this is pointing the tires away from each other, makes the front of the car more responsive and is recommended on most road racing cars, as it makes the car turn in easier. Toe In, pointing the tires towards each other, makes the front of the car less responsive/more stable. Generally that's it, and that works just all right for most setups ... however I beg to differ. I will talk about that later, however.

Rear Toe: Adjusting overall behavior

Front toe only affects your car during corner entry and during bumps, when one of the tires isn't in complete contact with the road. Rear Toe, however, will adjust the behavior of the car during straight line driving, braking, corner entry, mid corner, corner exit ... you get the point. If you desperately need to change the behavior of the car using Toe, you use the rear Toe angle. 

For rear wheel drive cars like our F1 machines, the consensus is to always run Toe In. Under normal driving, Toe In will have the rear tires stabilitzing the car. The car will feel more planted and stable, though you might also call this understeer. Under power, the same thing happens. The power is trying to go towards the centerline of the car, this adds stability. 

That said, Toe Out is still an option. Toe Out will do the opposite, the rear will be more willing to rotate around corners. Not necessarily sliding, however. Since the wheels are pointed outwards, the outside rear tire is more free to follow it's natural curve around a corner. This adds car rotation, though you might know this as oversteer. Under power, it gets more sketchy. Since the wheels are pointed outwards, each one wants to do it's thing. One might win over the other and oversteer will ensue. Rear Toe Out is the recommended Toe setting on understeery Front Wheel drive cars. On our high power, rear wheel drive machines, it is a high risk, high reward setting for drivers that like oversteer.

Side effects

While Toe is good, do realize that by adding Toe you are making the tires face an angle while going down the straights. They will be "slipping" or "dragging" accross the surface of the road. While Toe on it's own won't overheat the tires unless you are packing more than you could ever setup, it will reduce the cooling rate of the tire. The tire will be hotter simply because it can't cool off as much. This same slipping and increase temperature will also wear out the tire a bit quicker.

I also called it "dragging" for a reason. The tire not rolling straight ahead down the straight will result in an increase of its rolling resistance. As you know from the Tire Pressures section, high rolling resistance kills the top speed and acceleration of the car. That means that the faster the track, the less toe you can get away with. Monza is a good track to use low Toe, while Monaco won't suffer much from high Toe.

Going on a tangent: Camber Thrust v Toe Forces

Remember that, since we are road course racing, we are using negative camber on both front tires. As explained, this creates camber thrust, a force that helps adds cornering ability. And a force that will unsettle the car if only one of the tires is generating it. Toe also adds force. Toe Out will make the tires point outwards and generate outwards force, Toe In does the opposite, inwards pointing and inwards force. 

With this in mind, let's turn into a corner, shall we? Let's make it a right handed corner. If our car had front Toe Out, the right front tire will be pointed into the corner, will add some extra cornerning force ... then it will start to get unloaded and that extra cornering force will not do much. The left front tire, the one doing the most work, will start pointed the wrong way, and generating a force towards the outside of the corner. Basically, the camber and toe forces are fighting each other. Result, less cornering force than you should have.

Let's Toe In the tires, then. Same right handed corner. The right front tire will be pointed away from the corner this time around and will not generate as much cornering force. However, the right front tire doesn't do much work in this situation, as it will be quickly unload. The left front tire, however, will be already pointing towards the corner and already generating cornering force. This force is added on top of the camber thrust. Result? Extra turn in.

This might sound completely backwards to what you've usually heard, I know that. The effects of toe depend on how much involvement the inside tire has on the cornering. I don't claim to be a tire physics and vehicle dynamics expert (Hence why the definition of slip angle and other definitions will be a bit lacking in the technical side, I know I pissed off a few physics lords with that), I'm no where close to that. This is why you should test this kind of neboulous setup options, like front Toe, on your own and determine what works for you. With some many elements in play, what does something for you might work the other way around for me.

Do keep something in mind. The max Toe angle we can set in any direction is 1 degree, with the typical range being at 0,10° to 0.50°. The maximum steering angle the front tires will see on a typical track? 12 degrees. Hairpins? Around 18°. Monaco? Up to 23°. After turning into the corner, the effects of front toe become insignificant. A steering angle of 10° and 10.5° are so close as to one another as to be the same. Toe Angle is not a miracle adjustment.

Summary (F'ing finally)

• Toe angles is one of those driver dependant settings. We could have many drivers, all of them with different toe angles, and all of them would have the correct settings. There's not a true optimal toe angle.
• Front Toe is a very interesting setting, as its effects can vary from driver to driver. The simple rule, if you don't want to do a lot of testing, is to add Toe Out to increase front end responsiveness, Toe In to increase stability.
• Rear Toe is much more straight forward. Toe In makes the whole car more stable, while Toe Out adds free rotation.
• While Toe can be powerful, you will sacrifice Top Speed, Acceleration, Tire temp and wear for the benefit.
• It is a matter of perception, but Front Toe might not work the way the general consensus says it works.
• Do remember that your inputs will (nearly completely) override whatever Front Toe settings you have, so if you have problems mid corner, it isn't the Front Toe angle.
• While the whole range of settings is perfectly usable (Some keyboard users put a full degree of Toe In as their Rear Toe setting), generally safe settings are between 0.1° and 0.5°, preferably lower at the front.
• If in doubt, 0.1° of Front Toe Out and 0.3° of Rear Toe In are more than serviciable.