Threshold braking is when you brake as hard as you possibly can in your car. Sounds easy, right? After all, don’t you just push down the brake pedal harder?

In a word, no. Threshold braking is one of the hardest and most important skills to learn and master. The best way is, of course, actually practicing it. But here are a few pointers to get you braking in the right direction:

What is Threshold Braking?
Unless your brakes really suck (like the brakes on my Sentra), you should be able to lock up the tires if you push on the brake pedal hard enough. Threshold braking is simply apply the maximum braking force possible without locking up the tires. At this point, your car will be decelerating as fast as it can.

Why Not Just Lock Up the Wheels?
Yes, locking up all 4 wheels and leaving long tire streaks looks impressive, but it is not the quickest way to stop by a long shot. A tire loses 30% of its braking capability when it is locked instead of turning. Plus, locking the tires puts flat spots on them. I we all hate flat spots.

Threshold Braking With ABS
If your car has Anti Lock Brakes, threshold braking is easy. Take your right foot, and push the brake pedal to the floor has hard as you can. Harder. Make the pedal sorry it exists.

That’s it! The ABS will kick in, keep your tires from locking up, and you will threshold brake like a champ.

Threshold Braking Without ABS
This is the hard part. You need to find the exact amount of pressure that will lock up your tires, and then back off just enough to keep the wheels rotating. This is a key point. When you are skidding along with all 4 wheels locked, you are braking at 70% of maximum. Many people will pull back 1/2 of their braking effort or more to get the tires spinning again. That means you went from 70% braking (skidding) to 50% braking (letting off the brake). Less braking is bad. Don’t give up any more braking than you have to to get the tires spinning.

Usually, 1 tire will lock up before the rest. Which one locks depends on car setup, pavement conditions, and other things like banking and incline. It should be one of your front tires. If not, have your car adjusted, as you now have a dangerously reduced ability to brake. You are basically working with the limit of that 1 tire, and the other tires are along for the ride.

How Do I Know how much Pressure to Apply?
PRACTICE. Every car is a little different. Even my Miata is different with different brake pads, or when the same brake pad is hot or cold. You will only know the correct amount of pressure by braking over and over and over again. You will just feel the correct amount.

It is important to note that your maximum braking potential is entirely limited by your tires’ maximum grip (assuming of course you have appropriate brake pads and are not experiencing brake fade). This grip is constant, whether you are going 20mph or 200mph. Thus, your pressure for the same surface conditions will be the same at 20mph or 200mph.

The Process
So, how do you actually threshold brake without ABS? Think of it as a smooth squeeze on the brakes. You want to get on the brake pedal quickly but lightly at first. Give just enough pressure to shift the car’s weight forward. That is so important that I’m going to say it again in bold AND italics: give just enough pressure initially to shift the car’s weight forward.

As you will recall from Indepth Oversteer, tires have more grip when they have more weight on them. When you brake, the car’s weight shifts forward and provides additional traction to let you brake harder. So, threshold braking is really the limit of grip attained AFTER the weight transfers forward. Get on the brakes too hard too soon and you will lock up the front wheels prematurely.

Adjust for Road Conditions
Any braking zone is just that: a zone. There can often be various levels of traction throughout your braking zone. A patch of pavement might be wet. There may be bumps over a certain part. Or, like the inside of the braking zone of Turn 9 at NHIS , there might be a spot that, for whatever reason, is permanently more slick than the area around it. All of these things must be accounted for. In Turn 11 at NHIS , for example, I let off the brake partially when I hit the bump at turn in. If I don’t, I lock up the front right tire.

Why Would I Bother When ABS Exists?
For soccer moms that don’t care or know how to drive, ABS is a godsend. For the performance-oriented driver, ABS is an intrusion and, more often than not, a limitation. A good race car driver can adjust brake pedal inputs more minutely and with greater precision than even the best ABS systems out there. Braking on your own lets you squeeze additional braking performance out of your car.

There is also the issue of wanting to be able to lock up all 4 wheels. When would you want to do that, you say? Say you have the misfortune of spinning. Common wisdom once you are gone and out of control is, “when you spin, both feet in.” That is, push in the clutch, and push in the brake pedal. This makes the car just rotate around in a more or less straight line, without doing anything funny. This maneuver is near impossible, however, with ABS, and can actually be quite dangerous on a track or if you are pushing too hard on the street.

Where to Practice?
Threshold braking can be practiced anywhere. Just MAKE SURE THAT THERE IS NO ONE BEHIND YOU!! The law in most jurisdictions puts fault at the person behind you to avoid hitting you. But realistically, if you threshold brake with someone even a ways back, they will likely plow right into you.

The best place to practice is on a deserted back street. Practice going from 40mph or so to a dead stop. Once you have mastered the correct amount of pressure, start giving yourself markers. Say, “ok, I’m going to stop right at that sign up there,” and do a threshold brake to the sign. This is a lot harder than it sounds. You must correctly identify when to begin your braking zone so that threshold braking will stop you right at the sign.

Sound familiar? It should. That is the same thing you do every time you enter a braking zone on the track.

More than any other skill you will develop, the ability to threshold brake is the most important. When there is a problem in front of you and you need to stop, you better know how to stop as quick as you possibly can.