How To Brake?

[Skypalace]

Very interesting discussion.

My personal answer is that it depends on what the purpose is, of the session and lap. For all-out qualifying, trying to get every last hundredth (I just had a race weekend where top three of us were within 23 thousanths of a second in qualifying), then going from full throttle to full brakes is quickest, IF 1) you don't end up over-slowing and killing your mid-corner and thus exit speed, as is VERY often the case when using max brakes, and 2) you don't lock up your brakes (on a non-ABS car).

On a race pace, I'm usually (but not always) a little less aggressive in braking zones, I brake a little earlier and a little less hard, to reduce chance of lockup and give more room to increase braking if needed to make the corner. Depends of course on the competitive situation, am I chasing someone or forced to defend, or am I in a 'comfortable' position where keeping up a pace is all that's needed to prevent a position change.

The over-braking is what most people end up doing if they're trying to 'banzai' the braking zone, so that's why it ends up being better not to apply the brakes too hard - it lets them modulate their overall speed easier. At full near-lockup braking, any GT/Cup car has such amazing brakes that the speed comes off at a very prodigous pace, and it's very difficult to stop braking at the right point. Also, if you're aggressively braking, and you brake even a little too early, you need to reduce the braking forces a fair bit later in the braking zone to prevent over-slowing. All of this is much easier to control at lower braking levels, which I believe is why it's often faster (and certainly safer) to brake less. However, if you're getting off the brakes at the right time, and you're not locking up, simple physics says you want to be on the gas as long as possible, then on the brakes as late and hard as possible, to maximize your speed over every foot of the course. Not very easy for us mere mortals to do, and the additional time gained by late/hard braking is usually overwhelmed by the time lost in having too low a mid-corner and thus corner exit speed, killing speed all the way to the next braking zone.

I've learned a lot about braking while going from an ABS car (996 Cup) to a non-ABS car (997 Cup), with manual bias control. I've had to adjust my braking to trail-brake less and get more braking done before turnin, or I was regularly locking up the inside front wheel late into the corner. This actually caused me to change my lines somewhat.

In the wet (just came off a weekend with 5 wet sessions), I'm of course easier on the brake application, as I'm always sensing for traction, including under braking. Downshifting is less aggressive also (lower in the rpm range) or it'll cause rear lockup (in both 996 and 997 I use downshifting/engine braking to augment the car's rear braking).

Many drivers seem to want to maximize their braking, and brake as hard and late as possible. If they have data or video, I often see much more time to be gained in better controlling getting OFF the brake, and rolling through the corner as quickly as possible, and back onto the throttle as early as possible, minimizing time through the corner and all the way down the next straight. There's often a full half-second or more available there from a single corner, versus perhaps a tenth by braking a little harder and later. So yet another reason many instructors/coaches want you to concentrate on areas other than braking as hard as possible.

Final thought - for DE drivers (I instructed for many years but haven't lately), the goal is to get drivers safely around the track, on a good line, slowly increasing their speed as they approach the limits of their cars and their own abilities. It's way to easy to exceed the abilities of driver OR car by nailing the brakes hard, and lots of bad things can happen, as the start of a braking zone after a long straight is the fastest the car is going. I strongly believe (both in DE and in racing) in gently approaching limits from underneath them, and I've too often seen bad things happen in DE from things like mid-corner throttle lift from someone carrying more speed than they're comfortable with, or seeing something ahead that they're not comfortable with, even though their car can handle their current cornering speed.

Next topic: pinching exits, why do I see SO many drivers keep full (or nearly full) steering input well after apex, while applying full throttle, and not unwinding the wheel and going all the way to trackout? Have seen so many incidents... Another topic though :-)

[FTS]

What can I say, an excellent first post; welcome to the community Jim.

I certainly agree that the physics of vehicle dynamics dictate maximum braking for the shortest period of time and being on throttle for the longest periods is the fastest possible way around any circuit. The theory goes out the door when the human starts making the decisions; we are not consistent and most often not rational either.

What I find interesting and something that I would not have thought about is how you had to change your braking to use less trailing with a non-ABS car. It does make sense, I just would not have thought that might be one of the outcomes.

I have been watching F1 since 9-yrs old, that's over 30 yrs btw, and what grabs my attention the most is how seldom those drivers brake on a straight line. Granted they have significant help from their aero, but being on such balance and sensitivity is something to be admired I think.

I like your next topic as well, I hope you do start the thread

[Larry Herman]

Originally Posted by FTS

I certainly agree that the physics of vehicle dynamics dictate maximum braking for the shortest period of time and being on throttle for the longest periods is the fastest possible way around any circuit.

Fatih, why would you think that?

[bman]

Originally Posted by Skypalace

Next topic: pinching exits, why do I see SO many drivers keep full (or nearly full) steering input well after apex, while applying full throttle, and not unwinding the wheel and going all the way to trackout? Have seen so many incidents... Another topic though :-)

I am surprised how often I see this and it's scary! I can understand a beginner-intermediate driver doing it but I've seen it too often with intermediate-advanced drivers. Moreover, I have found a resistance to change when you point it out. I've found myself practically begging drivers to "OPEN THE WHEEL", lap after lap. And often the response is "WHY?"....You really get concerned when this happens because you worry the driver has limited feel/sense of what's going on.

I think it is applicable to this braking discussion because often it's a symptom caused by over braking and early release of the brake. The driver isn't rolling into a corner, so they're on the throttle too early.