winders

I don't see where what you showed invalidates what I said....

Scott

bobt993

Larry, the reason it was suggested to get an instructor in the car is you need to develop a feel for grip and slip from both seats in the car. Learning faster entry is much easier if demonstrated and you "feel" then "ingrain" the sensation into your senses. Telling someone to simply brake less will omit the subtle balance adjustment needed in steering, throttle, braking. When it all comes together it feels right, but initially it feels too fast and uncomfortable.

PedroNole

Well, not to pick a fight but I just disagree with this... Now that you've introduced WHICH braking skill is/isnt the most critical to learn, I would absolutely say that threshold braking is a definite requirement in the driver's arsenal. Further, you absolutely need to know how to do it to go faster. A little faster isn't "a lot faster" but it's still faster. If you're doing 160+ mph going into turn 1 at Road America you should absolutely go to the brakes as late and hard as you can WHILE still not over-slowing/upsetting the car. It's much easier to get off the throttle early, scrub a lot of speed over a greater distance and make a nice balanced turn. Put me next to that guy any day and I'll pass him and still make it stick.

FFaust

Yeah baby, lets dance

winders

Pedro,

I don't disagree with anything you wrote here. As racers, we do need to learn all of the braking skills. I just think "threshold braking" gets far too much emphasis considering how often it is actually used.

Maybe car racers are different. When I was instructing motorcycle racers, I spent less time on threshold braking and much more time working on (in no particular order):

1. Where to brake.
2. How much to brake.
3. How quickly to apply and release the brakes (not upsetting the bike too much).
4. Trail braking.
5. Not coasting (often caused by braking too soon, too much, or a combination of both).
6. Using the brakes to control line.
7. Using the brakes to manage the chassis.

More often than not, the racers I worked with would brake too much and too late. It sure felt fast to them. But they would see the light when their lap times improved quite a bit and what they were doing was easier to repeat and less error prone.

Yes, we would work on threshold braking too. Most tracks have a turn or two where you need to do it. It's a great tool for passing and to prevent from being passed. I just don't rate threshold braking at the top of the list of braking skills to perfect.

Scott

ervtx

I'm just saying that I don't think you would want to say that threshold braking is "not exactly the most critical braking skill too learn" in front of a group of beginner DE students. Instead, you might want to say that it is a foundational skill that needs to be mastered for safety purposes. Two very different messages.

winders

We're not teaching a class here. We are having a discussion.....

Scott

AC coupe

Sorry to jump in but... how can you not learn what the absolute braking limit of your car is and hope to go faster?

Brakes are evil things, you want to use them for as short a period of time as possible since they, you know...just slow you down

From all the data traces I have seen most time at WOT and least time spent decelerating or coasting always wins.

cheers!

Larry Herman

Not sure what data you have been looking at. Maximizing time spent at WOT does not typically go hand in hand with minimizing time spent decelerating.

winders

AC Coupe,

I wasn't suggesting that you should not know how to brake and the limit. My complaint is the emphasis placed on the skill compared to how little you actually use it.

Again, I will pull from my motorcycle racing background. Most of the time you decelerate, you are not using the brakes at their threshold for lockup limit. I bet that if you looked at the data for the fastest car racers, they are not braking at the limit most of the time. It upsets the chassis too much and certainly doesn't work well when the steering wheel is not straight. Braking at the limit reduces your control of the situation and is certainly more error prone.

Scott

FFaust

Scott don't worry, I understand what you are saying, and agree with you, in spite of my limited experience

For safety reasons, or simply to educate the new driver, threshold braking is one of the first skills taught, and so it tends to "stick". It then has to be "unlearned", or de-emphasized, as the driver progresses and starts to get faster.

One has to know where threshold is, and how it feels, if one is to have proper knowledge of the handling "envelope", and of what is possible.

For the upcoming (read intermediate) driver, I wonder if there is not a "fear" that, if you are not threshold braking, well, you just weren't going fast enough in the first place, and therefore leaving some time "on the table"?

winders

Francois,

Thank you.

I suspect you are correct on all counts.

One of the drills used at all the novice track rider schools I participated in or taught at did indeed teach riders about threshold braking.

Funny, I had forgotten about that. Probably because this was only stressed at the novice level. I was either going to more advanced schools for racers or teaching experienced track day riders and racers. We discussed late braking passing techniques but never specifically focused on threshold braking. More often than not, the more advanced students were braking too hard instead of not hard enough.

Maybe in world with ABS, this is a more complicated matter.

Scott

ProCoach

Great discussion!

I've backed off of my "threshold braking all the time" approach to a more measured view (now that I've been working again with less quick cars), but I still think there is a time and place and I think that for many, a great deal of improvement can be made honing this technique. Knowing when, where, how and why helps a great deal in the bigger picture of going faster.

Bingo!

Yes, this is supported by the data and practical experience.

Larry, I think he's talking about maximizing time WOT UP TO the braking zone and making that braking zone most effective by braking most efficiently.

Your observation is certainly the case if the car is not completely straight when it comes time to quit WOT and start the "speed adjustment" or slowing phase.

Into T1 at Thunderbolt, VIR, Summit, the Glen and many others is an example where you a) want to be at WOT for the greatest possible distance, b) make the transition between WOT and maximum decel as quickly as possible (covering the least distance) and c) minimize the amount of distance covered during the speed adjustment required to make the car follow your directions at turn-in.

Since most drivers don't (or can't) threshold brake (at or near the limit of the tire's traction) conistently or at all, it's exceedingly important that all drivers be at least conversant and practiced in the skill of threshold braking.

According to the data, the fastest drivers ARE melding the braking and turning transition at the highest vMin possible without slowing further and reaching that critical speed required to do that effectively from vMax in the shortest distance (hence time) possible.

It's really not about the braking limit. It's about using the entire tractive capability of the car (through it's only connection with Earth, the four contact patches) at ALL times. Since most drivers are under that limit a great deal of the time when slowing, it's important to learn the range of braking at or near the limit, straight or bending into the braking zone.

I can say that coaches, instructors and people who are resources to those who desire to form an organized, safe methodology to achieve this skill have job security, if my broad (10,000+ client data files) experience is any guide.

fleadh

I've been avoiding posting in this discussion as I didn't want to ruffle any feathers, and by no means do I claim or practice to be a driving coach or instructor at any level. However, I've spent the better part of this year learning the differences between driving as it relates to DE, club racing, and pro racing.

IMO, If you want to go fast, you'll be threshold braking everywhere. Now, I say that to include over bumps, when the car isn't perfectly straight and settled, when you're off-camber, etc. If your intention is to slow the speed of the car and you're using the brakes to do it, you need to be using all the braking ability the car has (which changes based on where you are IN the braking zone, track conditions, or specific track location). This isn't what I tell to a beginning or intermediate driver, but once you decide you want to lap as fast as the car is capable of, you need to use ever bit of grip at your disposal.

T1-T2 at Infineon is a perfect example. If you're doing it rite, you'll be pulling over 1.5G lateral load in a Cup car while decelerating from 130+mph to about 50mph using the brakes, turning the car, and downshifting. During the entire time the car isn't really settled except for a few feet up the hill into 2. If you can't threshold brake in a straight line, you stand no chance of being fast here. I spent 2 days there with an ALMS pro last week and I can assure you, at no point were either one of us 'rolling into corners'.. it's attack or get out of the f*cking way. (i'd post the data trace for this section but i don't want to help any of my competitors before the pirelli cup race in a few weeks ).

I can't think of a corner where I brake on entry and don't try to use all the braking capability of the car.. even if it's only for a tiny amount of time. Granted, the speed at which you can go from full throttle to full braking is car dependent (softer the car, longer it takes), but I don't see why your goal as a driver would not be to use all that's available to you (if you are going for a fast lap).

edit: on thinking about it more, there are a few places among the tracks i've driven this year where i do 'brush' the brakes (sometimes, but not every time).. it's mostly just because i drive those sections like a soccer mom. but, it's definitely not the norm..

-mike

Larry Herman

Peter, I was probably a little too cryptic in my response. Maximizing WOT coming up to a corner means delaying the onset of braking until the last possible instant, requiring maximum deceleration in order to make the corner. Turns that require a large amount of deceleration like the ones that you listed do fall somewhat under this scenario. Consider however turn 10 at VIR, Summit and the Glen. They all require just the opposite, getting out of the throttle a touch early, with a gentle and possible longish brush on the brakes to maximize entry and mid-corner speed, with the onset of acceleration at a much later point in the turn. In all of these turns you are not maximizing your WOT time nor your braking, but you are cornering at higher speeds to offset that and actually be faster. But you know this.