By 
Certainly, if you’ve ever really taken a hard look at motorsports, you’ve likely heard this phrase. Sometimes, pushing your vehicle to the ragged edge is needed to gain the edge in a competitive environment. However, the vast majority of the time, it is more advantageous to focus on your position on the track and how your vehicle is reacting to the road conditions than it is about pushing past an obstruction/opponent. Your position is relative to where your vehicle is concerning the road itself, not placement among your opponents.
Depending on the drive wheels of your vehicle, the suspension dynamics, tires used, road conditions (weather, gravel, rough, smooth, etc.), the way you attack a corner, is one of if not the greatest determining factor to track times and performance. These factors can make or break your lap times and how your vehicle behaves; not to mention the consumables your vehicle will surely chip away.
Trail Braking
As defined via Wikipedia: Trail braking is a driving and motorcycle riding technique where the brakes are used beyond the entrance to a turn, and then gradually released. Depending on a number of factors, the driver fully releases brake pressure at any point between turn-in and the apex of the turn.
Seemingly counterintuitive, trail braking can make a significant impact upon your track times and the smoothness of your turning as you dive through the apex. The common methodology will tell you that you will want to brake hard before coming into a corner and then smoothly carve through it, steadily increasing power as you begin to straighten out. While this is indeed a solid technique and mindset, it is somewhat rare to find yourself in such a neutral position to be able to perform this action consecutively on a track. Differing your approach per corner is a key on-the-fly adjustment any serious driver will need to undertake.
Trail braking is typically used in competitive motorcycle races. Where it becomes beneficial for four-wheeled vehicles is in controlling pitch, yaw, and understeer. You should avoid, as much as possible, quickly coming off of the throttle, or brakes; of course the same could be said for quickly getting onto the throttle or brakes, too. Doing either can upset the balance of the vehicle and create undesirable turn-in or exit characteristics. The pitch of the vehicle, its suspension load, or angle when entering a turn should always have its weight shifted towards the front. Suddenly offloading the weight over the front of the vehicle can dramatically adjust front grip levels. The rear wheels of the vehicle will experience yaw; an ever so slight twist or oscillation throughout the turn. Trail braking helps to reduce this movement, with consideration to your brake bias setup.
If done properly, a trail brake can help to control unwanted characteristics upon corner entry or mid-corner. If your car tends to understeer, maintaining pressure on the brakes (not full pressure) after your turn has begun, can shift the load bias to both front tires providing greater levels of turn-in grip, instead of just loading the outside tires. Different levels of brake pressure and length of application can help curtail a slew of cornering characteristics. A rear-wheel-drive car that is nervous upon entry and may be prone to snap oversteer, may want to be brake heavy on corner entry and then prolong their release until just before they are ready to apply slow, progressive power for the exit. Practicing this technique is important as no two cars are alike, no two race days are alike and no two drivers are alike.
There are two prevailing schools of thought about how this technique should be employed. Heel-toe or left-foot braking. Predominantly, heel-toe braking will be favored among all automotive enthusiasts. This is largely due to the fact that vehicles tend to come in both manual and automatic/DCT transmissions. If you develop a habit of left-foot braking, you may find yourself in a tricky situation if you were to suddenly drive a manual transmission vehicle in a competitive environment. It is imperative that you are ready to downshift in a manual transmission vehicle upon corner entry. Therein, heel-toe braking is really the only way to accomplish this if your vehicle does not come equipped with an auto-rev-match feature. However, I will extend an olive branch. If you know that the only vehicle(s) you will be driving are going to be automatic or DCT equipped, it does not hurt you to use left-foot braking. Allow me to explain my logic on this. Efficiency–if you consider the idea that pressing two pedals with two feet is more efficient than pressing two pedals with one foot, you may see the premise under which I am presenting my argument. Properly utilized, left foot braking with an automatic or DCT can be more effective than just heel-toe braking.
Shifting the balance of the car by quickly loading or offloading the brakes upon entering a turn can dynamically adjust grip levels throughout the turn. Suddenly coming off of the brakes will adversely impact the front end grip. You should, in my opinion, be coming off of the brakes completely, after proper modulation, just before the apex. Not too much time is spent on teaching drivers to modulate the throttle upon corner exit since people are typically all too familiar with oversteer and torque steer. Engaging in smooth exits is almost ingrained into each driver but, how many of them stop and think about how their braking dynamics can impact their grip levels through a turn? The majority of the time, drivers are off of their brake and throttle, while holding on tight until they can power through the rest of the turn.
As with anything, timing, technique, and practice is everything. Your driving habits, your vehicle, and road conditions will dictate much of how you will approach the apex and subsequently exit it.
