Camber

Camber is a measure of how much the tire leans toward the chassis. A wheel is said to have negative camber if the top of the wheel is leaning towards the chassis.

+ve Camber reduces lateral grip

So, what does camber do and what are the trade-offs? As shown in the image below, when a car with zero degrees camber is in a corner both tires will lean towards the outside of the corner as the car leans causing the tires to reduce the size of their contact patch with the driving surface. As a result of reducing the contact patch area traction is reduced as shown in the first two examples in the diagram below.

-ve camber (too a point) gives you more lateral grip

If we add the optimal amount of negative camber then as the car leans during cornering the outside tire will have the maximum contact patch and thus improve traction during cornering, as shown in the last example in the diagram above. By adding negative camber the inside tire does have less contact patch and thus less traction, however the increased grip on the outside more than compensates. This happens because the outside tire has a much higher vertical load than the inside tire. The greater the vertical load a tire has the more grip it has. On a road racing car, it is most important to optimize the contact patch of the outside tire. Now in oval car racing they will add positive camber to the inside wheels to further optimize the contact patch of the inside tire. They can get away with this because oval cars only turn one way.

Too Much Negative Camber

Like every setting discussed here, you can go too far. In other words, if you add too much negative camber you will actually reduce lateral grip. This happens because the tire never rolls over enough to offset the negative camber, which results in less than optimal contact patch.

How to find the optimal camber

First what does optimal mean in this context? It means that you are maximizing the utilization of the surface area of the tire. For example, you have too much camber and the tires are not using the outer half of the tire you will see the tire temperatures and tire wear on the inside of the tire be far higher than the middle and outside of the tire.

There is no precise way to guarantee you have the optimal camber, but you can approximate it by looking at the tire temperatures and tire wear on the inside and middle of the tire. The closer those two temperatures are to each other the in general, the more optimal your camber is. They will likely not be the same but if the temperatures are within a few degrees of each other and the tire wear after a full stint is within a few percentage points then you likely have the optimal camber. In general, the outside third of the tire will always have less temperature and tire wear than the middle and inside thirds of the tire.

More -ve Camber Reduces Braking and Acceleration grip

With negative camber, the tires lean in, so a smaller amount of the tire is in contact with the road surface (i.e. a smaller contact patch) when just going straight. The inside third (ish) of the tire is the only part of the tire in contact with the road. The more negative the camber the less contact patch you will have under braking and acceleration thus reducing the braking and acceleration grip you have.

Controlling balance with rear Camber

Camber is an immensely powerful setting option that has a dramatic effect on the balance of your car. I think by now you understand that if you decrease the negative camber in the rear of the car this will in general make the car loose. However, it is important to understand where in the corner this extra oversteer is likely to occur. The reduced negative camber in the rear will have the biggest impact on the rear losing grip when the car is at maximum lateral load because that is where the tire is likely not using enough of the inside of the tire due to the lateral force. However, at early stages of corner entry you will likely experience more rear grip, as that reduced static camber is likely allowing a larger contact patch at corner entry because the lateral load has not reached its maximum yet.

So, if you want to add stability on corner entry and free up the car at mid corner then reducing the rear Camber can work very well.

Controlling balance with front camber

In general, iRacing cars seem to do best with max or near max camber for most tracks. Having said that if you want to reduce the oversteer through the corner, reducing the front camber can help. The added benefit of reducing that front camber is that as mentioned above you will increase your braking performance as the tire will have a larger contact patch under braking.

Handling Scenarios

In each of the following scenarios, here are things you will help you improve the handling by making changes to camber. 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

• Reduce negative camber at the front. This will have the bigger impact in an off power situation because you have transferred more weight to the front tires.

• If loose mainly on corner entry and not mid corner then reduce negative camber at the rear.

• If loose mainly at mid corner where the maximum lateral load is then increase rear negative camber. This is typically not when you are off power, but it depends on the corner.

Loose on Power

• Increase rear negative camber. This will have a bigger impact in an on power situation because you have transferred more weight to the rear tires.

• Reduce negative camber at the front.

Push off Power

• Increase front negative camber. This will have a bigger impact in an off power situation because you have transferred more weight to the front tires.

• If you push mainly on corner entry and not mid corner then increasing negative camber at the rear could help on the initial turn in but likely going to make things too pushy at the middle and exit.

• If you push mainly after the initial turn in up to mid corner where the maximum lateral load is then decrease rear negative camber. In general, this tends to be the better way to go with respect to rear camber.

Push on Power

• Reduce rear negative camber. This will have a bigger impact in an on power situation because you have transferred more weight to the rear tires.

• Increase front negative camber.