Understanding Maximum Rotation Point (MRP)

The concept of MRP reminds us that whenever speeds are going down, the rotation should be going up. If you have a corner where you're braking and the minimum speed point is at the middle of the corner, that means you should peak your rotation right there. The yaw rate graph shows us exactly how much the car is rotating. If there is a moment where you get more rotation on entry at higher speed and then you have less rotation mid-corner at a lower speed, that means your balance is off and the usage of your lateral grip is off. Unless the car has some serious car setup problems, that should not happen.

Characteristics of a Well-Defined MRP

A well-defined MRP displays the following characteristics:

• The rotation keeps increasing all the way into the minimum speed point

• The peak yaw matches the peak steering and the minimum speed point

• Rotation starts going down as the speed increases

• The MRP divides the corner into two parts: one where you spiral down into more rotation, and a second where you spiral up away from the rotation

• Never gaining rotation on exit

Oversteer on Exit Without Gaining Rotation

It's possible to experience oversteer and even perform a countersteer on exit while not actually gaining rotation at any time. The yaw rate continues going down, but because the yaw rate was not going down fast enough for the amount of speed being gained, the car could not handle it and the rear tires started breaking grip.

Reading Yaw Rate Graphs

Understanding Graph Directions

When reading these graphs, it's important to understand the following conventions:

• Steering goes right when it's negative and left when it's positive

• Speed is straightforward: more speed shows higher on the graph, less speed shows lower

• Yaw rate follows the same pattern as steering: the graph goes down when the car is yawing to the right and up when the car is turning left

Identifying Oversteer and Understeer

The relationship between steering and yaw is always what's going to tell you if you have oversteer or understeer:

• Oversteer: If you have a little bit of steering but the car is yawing a lot

• Understeer: If you have a lot of steering but the car is not yawing

While it's very difficult to actually measure this precisely because you don't know exactly what are the proportions of the graph, this information provides useful context for understanding your car's behavior.

Losing the Rear on Entry

When you lose the rear on entry, the graph shows more rotation than the car was capable of handling at that speed. The rear tires break grip, requiring a countersteer before quickly bringing the car back to the limit and pointing it in the right direction. This creates two peaks of rotation: one with the correct speed (exactly what you want) and another peak of rotation at a higher speed that the car is not capable of dealing with.

Correcting Oversteer Example

In some cases, correcting oversteer doesn't require too much countersteer. You may need to hold a little bit on the steering without actually pointing to the other side. The solution can be to drop the brakes a little bit more quickly, which shifts more weight to the rear tires more quickly and corrects the balance. After taming and controlling the aggressive start, you can bring the rotation back up again towards mid-corner.

Common MRP Patterns

A consistent pattern emerges in most corners:

• Minimum speed, maximum rotation, place to accelerate, peak steering

• Closing spiral under braking, opening spiral on power

• Closing spiral under braking, opening spiral on power

In most examples, the maximum rotation point or MRP is very close to the apex, where the intersection between the closing and opening spirals occurs.

When MRP Differs from the Apex

Acceleration-Based Corners

Not all corners follow the pattern of MRP being close to the apex. In corners where you're accelerating rather than braking, the MRP can occur much earlier in the corner. If you're accelerating and gaining speed, you have an opening spiral, which means if you're gaining speed you should be losing rotation.

Common Mistake: Adding Steering While Accelerating

A very common mistake occurs when drivers increase steering towards the apex while accelerating. This happens because we are wired in our brains to add more steering when we see that we're getting closer to an apex. However, you should only add steering if you're decreasing your speed. If you're on power, you should be opening up your steering, which means if you're doing an entire corner on power and gaining speed, the peak steering is at the very beginning of it.

Multi-Apex Corners

In corners with multiple apexes, different rules may apply to each apex:

• The first apex may have peak steering very close to the minimum speed, which is very close to the apex

• Getting back on power before the apex creates an opening spiral

• On the second corner, when changing direction while accelerating, you jump straight to the actual MRP

• The peak steering occurs way before the actual second apex

This means you have a huge distance between the MRP and the apex in the second part of the corner. In such situations, you get a lot more rotation on the first half because you are at a lower speed, and much higher speed on the second half. That means you have to turn in a little bit later than you think and turn in more aggressively to get the car to really point at the first half, and then the second half the car is going to be quicker and going on a straighter arc.

Flat-Out Corner Direction Changes

In situations where you're accelerating through a corner and then changing direction to a flat-out corner, you should already reach the peak steering as soon as you change direction. Change direction right away and then apply less and less steering as speed increases.

The Apex Trap

Many drivers tend to add steering when they see a curb because they think "that's a curb, that's the apex, increase steering on the way to that apex," and that's not correct. If at one point you have a certain amount of steering, and then later you have more speed than before but also more steering, you are definitely going to be over the limit at that point and destroying the front tires if you weren't at the limit before.

The tires will suffer and struggle, understeering and scrubbing, because you are asking for way too much from the car by expecting more rotation with more speed. The reason drivers do this without even noticing is just seeing the apex. We are wired to add more steering when we see an apex, when we go from the outside on entry towards the inside mid-corner. We are doing more steering in 95% of the corners, and that's why we don't realize that there are moments where this is wrong.