When accelerating out of a corner in the GR Yaris, the front tires can sometimes begin to push toward the outside.
I had been struggling with this kind of late-corner understeer.
However, during a driving lesson with a professional racing driver, I learned that one of the main causes was not my throttle input after the clipping point.
The real problem had already begun earlier, between the end of the straight and the clipping point.
I was not slowing the car enough before turn-in, so I was carrying too much braking work into the corner. As a result, the outside front tire was being asked to handle both heavy braking and cornering at the same time.
The symptom appeared in the second half of the corner, but at least in my case, the conditions that caused it were created during corner entry.
In this article, based on a professional driving lesson in my 2020 GR Yaris 6MT, I will explain why insufficient braking at the end of the straight contributed to late-corner understeer, and how I changed my driving from braking through turn-in.
For a broader explanation of braking, trail braking, steering angle, and throttle application throughout an entire corner, see my separate article: The Outside–Inside–Outside Line Is a Result★Cornering Basics Through Trail Braking and Steering Angle
Here, I will focus specifically on the section from the end of the straight to the clipping point.
My First Professional Driving Lesson in About Three Months
After a break of roughly three months, I took another driving lesson with a professional racing driver.
The instructor was the same person as before.
What I particularly appreciated was that he did not explain things only in terms of feel. He also explained why each input was necessary from a technical point of view.
I tend to understand driving better when I can first understand the logic behind it, so this approach was extremely useful for me.
During my first lesson with him, I realized that I had hardly been using the tires’ lateral grip properly.
Until then, I had been trying to drive the car as straight as possible without rotating it enough through the corner.
Correcting that alone produced a substantial improvement in lap time.
But after that, I struggled to understand the next step.
In particular, with my 2020 GR Yaris 6MT, I was experiencing understeer in the second half of one specific corner.
So this time, I focused the lesson on that single corner.
First, I drove while the instructor observed from the passenger seat.
Then he explained what I was doing wrong and how to correct it.
Finally, I rode with him while he drove, allowing me to experience the correct inputs and the resulting vehicle behavior directly.
The Problem: I Was Overusing the Front Tires on Corner Entry
The instructor’s main criticism was that I was asking too much of the front tires during corner entry.
More precisely, I had failed to complete enough braking at the end of the straight and was carrying strong deceleration too far into the turning phase.
Forward weight transfer under braking is not itself a problem.
To initiate a turn effectively, it is often useful to take advantage of the front-tire load created by braking. Increased front loading helps the front tires generate lateral force and begin rotating the car.
The problem is how much braking remains, and for how long.
I was entering the corner at too high a speed while maintaining substantial brake pressure and simultaneously applying a large steering angle.
That meant the outside front tire was being asked to perform two demanding jobs at the same time:
- decelerate the car;
- change the car’s direction.
Because my entry speed was too high, I also needed more steering angle to force the car onto the intended line.
So the problem was not simply that I was transferring load onto the front tires.
The problem was that I had not completed the necessary deceleration before turning and was demanding too much braking and cornering force from the front tires simultaneously.
Why Overusing the Front Tires Makes the Car Slower
A tire can generate only a limited amount of total friction force.
Under heavy braking, much of that available force is being used longitudinally to slow the car.
If a large steering angle is added at the same time, the same tire must also generate substantial lateral force.
When the combined demand for braking and cornering exceeds the tire’s available friction, adding more steering does not make the car turn more.
Instead, the front tire begins to slide outward and understeer increases.
When I say I was “overusing the front tires,” I mean that most of their available friction was already being consumed by braking and cornering, leaving very little reserve for additional lateral force.
If you enter too fast, maintain strong brake pressure, and add a large steering angle, there is almost no grip left in reserve at the front.
Turning the steering wheel more does not solve the problem.
The car simply becomes less willing to follow the intended line.
There is another problem as well.
If strong braking continues deep into the corner, the vehicle remains heavily loaded toward the front.
Front-tire load increases, while rear-tire load remains relatively low.
That can reduce the amount of lateral force the rear tires are able to contribute.
The result is that the car does not use the full cornering potential of all four tires.
In my case, I was trying to rotate the car almost entirely with the front axle.
The front tires were overloaded and running out of friction capacity, while the rear tires were not being used to their full potential.
That is not an efficient way to corner.
The car is less stable, and the total lateral force available from all four tires is not being fully exploited.
Why Late-Corner Understeer Can Begin at Corner Entry
If you enter too fast and continue braking heavily into the turning phase, you need a larger steering angle to reach the clipping point.
If that large steering angle remains near the clipping point, it is also likely to remain after the clipping point.
Then, when you begin applying throttle, the front tires are asked to do even more.
The GR Yaris is an all-wheel-drive car, so the front tires also transmit some drive force.
If the front tires are already using a large proportion of their friction capacity for lateral force because of the large steering angle, adding drive force can push them beyond their available grip.
The result is that the front tires can no longer maintain the intended line and begin sliding toward the outside of the corner.
The symptom appears as late-corner understeer.
But one of the conditions that created that understeer was already present much earlier: insufficient braking at the end of the straight and excessive workload on the front tires during entry.
Of course, late-corner understeer is also affected by the relationship between steering angle and throttle opening after the clipping point.
But correcting only the exit phase will not completely solve the problem if the car enters the corner too fast and is already carrying excessive steering angle.
The Solution: Make All Four Tires Participate in the Corner
So how should the problem be corrected?
The first step is to complete most of the necessary deceleration at the end of the straight.
The instructor’s direction was to stop carrying strong, deceleration-focused brake pressure deep into the turning phase and overloading the front tires.
Instead, most of the required speed reduction should be completed while the car is still largely straight.
Then, as turn-in begins, brake pressure should be reduced.
Reducing braking demand frees up more of the front tires’ friction capacity for cornering.
Steering angle can then be increased in proportion to that newly available lateral grip as the car approaches the clipping point.
However, “cornering with all four tires” does not mean eliminating weight transfer.
Weight transfer is unavoidable.
Braking shifts load forward.
Acceleration shifts load rearward.
Cornering shifts load toward the outside tires.
There is no need to eliminate these movements.
At turn-in, the driver still uses the front-tire load created by braking to initiate rotation.
But when braking remains close to maximum, much of the front tires’ available friction is being used for deceleration.
Adding a large steering input in that condition makes it easy to exceed the tire’s combined friction capacity.
The solution is therefore to finish the strongest deceleration at the end of the straight and reduce brake pressure as steering input increases.
As braking demand decreases, more front-tire grip becomes available for turning.
At the same time, gradually releasing the brake allows some of the forward-biased load to return rearward, helping the rear tires contribute more lateral force.
Written out in words, this sounds like a long process.
In reality, it happens within fractions of a second.
“Using all four tires” does not mean applying equal load to all four tires.
It means creating a condition in which each tire can contribute cornering force according to the load it is carrying.
The First Correction: Finish the Necessary Braking on the Straight
The first thing I changed was my braking at the end of the straight.
Previously, I was braking too late and had not slowed the car enough by the time I needed to begin turning.
As a result, I was still braking hard while entering the corner, placing excessive demand on the front tires.
After the lesson, I moved my braking point slightly earlier.
While the steering wheel was still close to center, I performed strong braking over a relatively short period and distance, completing most of the necessary deceleration before turn-in.
The important point is not simply to start braking earlier and brake gently for a long time.
The idea is to move the braking point slightly earlier while still performing the strongest braking efficiently on the straight.
By the time turn-in begins, the car should already be close to an appropriate corner-entry speed.
Once entry speed is correct, there is less need to add excessive steering angle simply to force the car onto the intended line.
Transitioning from Heavy Braking to Trail Braking
Even after completing most of the required deceleration on the straight, I do not completely release the brake pedal at the exact moment of turn-in.
Instead, I reduce brake pressure and progressively release the brake while increasing steering angle.
The sequence is approximately this:
- At the end of the straight, use strong, short braking primarily for deceleration.
- At turn-in, reduce brake pressure as steering angle begins to increase.
- After entering the corner, continue releasing the brake while increasing steering input toward the clipping point.
This transition from decreasing brake pressure into increasing cornering force is trail braking.
Trail braking is not simply the technique of keeping your foot on the brake as late as possible.
Its purpose is to transfer the tire’s workload smoothly from braking to cornering.
As brake pressure decreases, more of the tire’s available friction can be used laterally.
Steering angle can then increase in proportion to that available grip.
At the same time, releasing the brake gradually reduces the strong forward weight bias, allowing the rear axle to regain load and contribute more effectively to the turn.
Reduce the Front Tires’ Work Early and Bring the Rear Tires into the Corner
In my previous driving, even as I approached the clipping point, the front tires were still carrying a large amount of both braking and cornering demand.
After the correction, most of the main deceleration was completed on the straight, and brake pressure was progressively reduced after turn-in.
That reduced the amount of deceleration work being performed by the front tires and freed more of their friction capacity for cornering.
At the same time, as the forward weight transfer gradually decreased, rear-tire load recovered.
The rear tires could then generate more lateral force and help maintain the turn.
In simple terms:
Use the front tires to initiate the turn, but do not ask the front tires to complete the entire corner by themselves.
The front tires are still essential.
But instead of relying on them for everything, the driver establishes the car’s rotation and then allows the rear tires to participate in generating the total cornering force.
That difference has a major effect on cornering speed.
Modern Road Cars Can Corner Better Than Older Cars
According to the instructor, modern production cars can corner far better than older generations of road cars.
Tires, suspension design, body rigidity, driveline control, and electronic systems have all improved.
As a result, modern cars often do not require the same extreme front-loading techniques that were once necessary to make a road car rotate.
If a driver still creates excessive forward weight transfer and tries to turn almost entirely with the front tires, the front axle may actually be pushed unnecessarily close to its limit.
It is often more effective to distribute lateral work between the front and rear tires.
The advantages include:
- less concentration of workload on the outside front tire;
- greater lateral contribution from the rear tires;
- more effective use of the combined grip of all four tires;
- a better chance of maintaining higher speed through the corner.
The GR Yaris was not lacking cornering ability.
I simply was not using all four tires effectively.
Real-World Result the Day After the Lesson
The day after the lesson, I returned to the same circuit and drove alone.
The results were:
Before the lesson
1:50.764
Top speed: 201.6 km/h
After the lesson
1:49.661
Top speed: 199.3 km/h
Both laps were recorded in my 2020 GR Yaris 6MT.
The lap time improved by approximately 1.1 seconds.
Interestingly, the recorded top speed decreased.
My assumption is that the speed measurement point was located near the end of the straight, close to the area where I had moved my braking point slightly earlier.
In the improved lap, I began braking slightly earlier, completed most of the required deceleration while travelling straight, and created a better condition for recovering rear-tire load after turn-in.
As a result, the recorded speed at that particular point may have been lower, even though the section from corner entry to the clipping point was faster overall.
A higher top speed does not necessarily mean a faster lap.
You can maintain speed farther down the straight, but if that compromises the following braking and cornering phase, the complete corner sequence may still be slower.
I think these results illustrate that point very clearly.
Conclusion: My Late-Corner Understeer Had Already Begun at Corner Entry
The late-corner understeer I experienced in the GR Yaris was not simply a problem with throttle application at corner exit.
At least in my case, one of its major causes could be traced back to what I was doing between the end of the straight and the clipping point.
My sequence of mistakes was:
- braking too late for the required deceleration;
- failing to reach an appropriate speed before turn-in;
- carrying strong braking too far into the corner;
- concentrating both braking and cornering demand on the outside front tire;
- using up most of the front tire’s available friction;
- failing to bring the rear tires fully into the cornering process.
The corrections were:
- move the braking point slightly earlier;
- perform strong braking over a short distance while steering angle is near zero;
- reduce brake pressure while increasing steering angle at turn-in;
- reduce the concentration of workload on the front tires;
- create more front-tire friction capacity for cornering;
- recover rear-tire load and use all four tires to generate lateral force.
Weight transfer is still used.
The front tires are still used to create yaw and initiate the turn.
But that condition should not be maintained longer than necessary.
The front tires begin the rotation. Then, as brake pressure is released, the rear tires are brought progressively into the cornering process so that all four tires can carry the car toward the clipping point.
Finding the right balance determines how quickly the car can travel from corner entry to the clipping point.
After the clipping point, the challenge changes.
The driver must progressively unwind the steering while increasing throttle.
If too much throttle is applied while a large steering angle remains, the front tires may be asked to generate more combined lateral and drive force than their remaining grip allows, producing late-corner understeer.
I discuss that part of the corner separately in How to Avoid Understeer on Corner Exit in the GR Yaris: Steering Angle and Throttle Opening.
I also discuss why modern cars can corner differently from older cars in Cars Can Corner Better Than Before — So Driving Technique Has Changed Too.
At 61, I am still very much an amateur driver.
But I remain fascinated by the process of understanding what the car is doing, testing that understanding on track, and gradually improving the way I drive.
This article focused on the section from the end of the straight to just before the clipping point. For the next phase, from the clipping point to corner exit, see How to Avoid Understeer on Corner Exit in the GR Yaris: Steering Angle and Throttle Opening.
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