Toe

The static toe of a car applies to both the front and rear suspension. As shown in the diagram below, the front tires have static toe-out and the rear tires have static toe-in when the distance "A" is longer than the distance "B". The amount of static toe-out at the front and the amount of static toe-in at the rear have a dramatic effect on the balance of the car during cornering.

Slip Angle

Before we can explain how toe affects handling, we need to understand the concept of slip angle and how that affects tire grip. Slip angle is the angle between the direction in which a wheel is pointing and the direction in which it is traveling.

The key point here is that tires will generate their maximum grip when they have some amount of slip angle. Different tires have different optimal slip angles to generate maximum grip, so experimenting with slip angle can help fine tune the grip you can achieve.

Front Static Toe Impact on Handling

Since we cannot change something called Ackermann in iRacing which would allow you to affect the front toe dynamically as you turn the wheel more, we are limited to just talking about using static toe.

As a general rule of thumb, the more front tire toe-out you run the more turn-in steering you will have and the less steering you will have mid corner to corner exit. It then follows that less front tire toe-out you run the less turn-in steering you will have and the more mid corner and corner exit steering you will have. Please keep in mind that since there is an optimal range if you go too far with your adjustments you will get the opposite results.

Rear Static Toe Impact on Handling

The more rear tire toe-in you run the less steering your car will have. Running static toe-in on the rear of the car the rear outside tire has a greater slip angle compared to no static rear toe-in. This gives the outer more grip due to the higher slip angle. Since the outside tires contribute significantly more to the lateral grip of your car, more rear toe makes the car have less steering.

Keep in mind that the more rear toe in you run on your car, the larger the slip angle will be causing the rear tires to heat up more. Too much heat in the rear tires may cause you to loose rear grip later in the race.

Since a tire has an optimal slip angle at a certain load on the tire to generate maximum grip you should experiment with different rear toe-in depending on the tires you are running to achieve the car balance you are looking for.

Handling Scenarios

In each of the following scenarios, here are things you will help you improve the handling by making changes to the front and/or rear static toe. You don't need to do all of the suggested changes listed below in these scenarios. It is best to start at the top of the list and do one at a time.

Loose Off power

• Decrease the front toe-out for less steering at initial turn-in.

• Increase the front toe-out for less steering after initial turn-in

• Increase rear toe-in

Loose On Power

• Increase the rear toe-in

• Increase the front toe-out

Push Off Power

• Increase the front toe-out for more steering at initial turn-in.

• Decrease the front toe-out for more steering after initial turn-in

• Decrease rear toe-in

Push On Power

• Decrease the rear toe-in

• Decrease the front toe-out