What Is Understeer And How Can Racecar Drivers Correct Understeer?
Before we begin the discussion of how racecar drivers can correct understeer, lets first understand what it is. Most of us are more familiar with oversteer as it is the "scarier" situation for most drivers. We know oversteer is when a driver asks more of the rear tires than the level of grip they can provide. This causes the rear tires to slide on top of the race track surface. Well, understeer is the same, except it is the front tires slipping over the track surface.
Looking for more detail on the difference between oversteer vs. understeer? Check out this great article
Now that we know what understeer is let's talk about ways we can fix it. Drivers tend to be frustrated more by understeer than oversteer because race car drivers have fewer tools in our arsenal to fix an issue.
The first step of understanding what we can do as drivers to help correct understeer is to understand how weight transfer effects the racecars level of grip. As a rule where the weight is, is where the grip is. When we accelerate the weight of the car shifts to the rear. When we brake the weight of the car shifts to the front. So, when we accelerate this tends to make the back of the car "more comfortable" for many drivers. The main reason for this is the shift in weight.
This concept should be the cornerstone of any good high-performance driver education lessons to new drivers.
If we have a car that understeers a lot, we want to try and shift weight to the front of the vehicle for a longer period of time into the corner. Understeer on corner entry is something that is easier for a driver to control thanks to the ability to trail brake. But, It is nearly impossible to shift the weight to the front on corner exits. If you are experiencing understeer on corner exit, we first need to work on being disciplined to delay initial throttle application until the point we can start unwinding the steering wheel.
Looking for more information on trail braking?
To try and delay our initial throttle application later than usual without losing speed we want to focus on rolling entry speed. We can work on understeer on entry by having more brake pressure after turn in to keep more weight on the front nose.
The general rule is trail braking will save you from having entry understeer, so if you are experiencing understeer before you get to apex than make sure you are trail braking all the way down until the apex. There is an exception to this rule where a driver can overwork a tire from too much trail braking, but this depends a lot on the actual set of tires and the car setup. But that is very rare and something most track day drivers, autocross drivers, and amateur racing drivers will not experience.
The idea of shifting our initial throttle application later and focusing on rolling more entry speed will be critical for any of you in front wheel drive cars. The FWD cars suffer much more from exit understeer and overheating front tires than any other, AWD cars will also tend to understeer a lot on exit.
Rear wheel drive cars will struggle more for traction on exit, so oversteer is more likely the issue on corner exit. Many drivers like to pick up throttle early to help their oversteer but this can lead to big issues on corner exits.
When a driver gets to throttle too early and induces an understeer they will have more steering angle at the exit of the corner. It is so important for drivers to be straightening their hands as they are squeezing back to full throttle. But, when you get to initial throttle too early you can't do that. Too much streering input combined with too much throttle, can end up causing the rear tires overtaking the front tires... which is not what we like to happen on the race track!
How do you know if you are getting to the throttle too early in general though? Well, the golden rule we teach at Racers360 is: If you can't start to unwind the steering wheel as you apply the throttle it is too early. If you have to turn even more after your initial throttle application, then you are too early to throttle.
The main takeaways we want you to have from this article on fixing understeer are the following:
- If you have understeer on exit: Focus on trail braking further around the corner and delaying that initial throttle application until the point you can really start to straighten the steering wheel.
- If you have understeer on the entry: It is highly likely you are not trail braking enough or possibly not at all. Check yourself to make sure you have some brakes on after turn in as you carve down to the exit. This should not be a large amount of brake pressure. It should feel as if your big toe is just lightly pressing down the brake pedal. Our goal here is not to be "slowing the car down" but consciously trying to keep weight on the front nose to help it grip.
We hope this article helps you and appreciate you visiting Racers360!!
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