Brake-ending point and Trailbraking...
01-24-2006, 11:30 AM
#1
Race Director
Thread Starter
Brake-ending point and Trailbraking...
This past weekend, we held the annual NNJR PCA region's Instructor's Workshop and Advanced Driver's Seminar. We had the honor of having Ross Bentley provide us with amazing instruction for both sessions. For those of you who do not know Ross Bentley - he is the author of the Speed Secrets series, has been racing for the past 29 years, and has been coaching on all levels for 22 years. The man knows a bit or two about performance driving.
Anyway, I'd like to share two concepts that he shared with us:
Brake ENDING point.
On the track, we all understand the 'Brake starting point.' Often in the pits, and here on the Rennlist, we discuss where we brake, IE: the STARTING point of when me have our foot on that middle pedal. We equate our braking zone to the point at which our foot first hits the brakes. "I brake at marker 200" or "I start braking at the crack in the asphalt just before the notch on the wall"...etc. Unfortunately, many people tend to have a starting point too early, and some have their points too late. Some over-brake, others underbrake and hang on for dear life whilst whipping around the corner - entrying the corner too fast, only to compromise their exit speed. All in all, it seems that we are not too consistent in the braking zone. (At least that's my case in many corners)
However, Ross contends that there may be a way of becoming more consistent in the brake zone - instead of focusing on the starting point of the brake zone, Ross Bentley suggests that the driver look further down track and focus on the brake ending zone - or somewhere around the turn in point of the corner. By focusing on this, and programming your driving on the track to adjust your braking based on this reference point, Ross argues that the braking will become more consistent.
By the way - we do this all the time on the street - at every stoplight, every stopsign, everytime we need to stop we aren't using a 'brake starting point' reference, but we're using the 'brake ending point' to judge when we start to decelerate and apply the clampers. So we already know this technique! On the track, it's just a little different - we don't stop completely (though it may feel that some do!) and we don't wait for the light to turn green before turning the wheel.
Trail Braking
Yes, Ross brought this subject up in the Advanced Driver's Seminar. Too bad ColorChange isn't here on Rennlist anymore. Ross suggested that trail braking is a helpful technique that can be used to overlap the braking zone and the turning of the car. He also suggested that it is helpful to rotate the car.
HOWEVER: he did mention that trail braking isn't the best technique in all cases. In fast turns with a great radius, trail braking should not be used - it would slow the car down too much. In tighter, slower, hair-pin like turns, trailbraking can be an effective technique to get the car rotated through the turn, and to overlap the braking zone with the turning zone.
In terms of newbies learning to drive on the track - he felt that the 'braking in a straight line' technique that many instructors teach may not be the best - after all, you are essentially teaching a student how to do something incorrectly. However, he also warned that instructors shouldn't advocate trailbraking for a new student either - newbies have plenty of other things to worry about. That said, Ross stated that many drivers develop trail braking naturally - and that if that is the case with a student, an instructor shouldn't discourage the trail braking student, provided he's doing the technique properly and for the right corners.
So these are just little snippets of what Ross was discussing. He did spend a whole lot of time on the psychology behind performance driving - how to develop the proper programming, how to integrate your left/right brain functions, and how to get into 'the zone.'
This workshop/seminar was perhaps the best classroom on performance driving I've ever attended. Please share your opinions on these techniques - I am curious to read your reactions...
-Z-man.
Anyway, I'd like to share two concepts that he shared with us:
Brake ENDING point.
On the track, we all understand the 'Brake starting point.' Often in the pits, and here on the Rennlist, we discuss where we brake, IE: the STARTING point of when me have our foot on that middle pedal. We equate our braking zone to the point at which our foot first hits the brakes. "I brake at marker 200" or "I start braking at the crack in the asphalt just before the notch on the wall"...etc. Unfortunately, many people tend to have a starting point too early, and some have their points too late. Some over-brake, others underbrake and hang on for dear life whilst whipping around the corner - entrying the corner too fast, only to compromise their exit speed. All in all, it seems that we are not too consistent in the braking zone. (At least that's my case in many corners)
However, Ross contends that there may be a way of becoming more consistent in the brake zone - instead of focusing on the starting point of the brake zone, Ross Bentley suggests that the driver look further down track and focus on the brake ending zone - or somewhere around the turn in point of the corner. By focusing on this, and programming your driving on the track to adjust your braking based on this reference point, Ross argues that the braking will become more consistent.
By the way - we do this all the time on the street - at every stoplight, every stopsign, everytime we need to stop we aren't using a 'brake starting point' reference, but we're using the 'brake ending point' to judge when we start to decelerate and apply the clampers. So we already know this technique! On the track, it's just a little different - we don't stop completely (though it may feel that some do!) and we don't wait for the light to turn green before turning the wheel.
Trail Braking
Yes, Ross brought this subject up in the Advanced Driver's Seminar. Too bad ColorChange isn't here on Rennlist anymore. Ross suggested that trail braking is a helpful technique that can be used to overlap the braking zone and the turning of the car. He also suggested that it is helpful to rotate the car.
HOWEVER: he did mention that trail braking isn't the best technique in all cases. In fast turns with a great radius, trail braking should not be used - it would slow the car down too much. In tighter, slower, hair-pin like turns, trailbraking can be an effective technique to get the car rotated through the turn, and to overlap the braking zone with the turning zone.
In terms of newbies learning to drive on the track - he felt that the 'braking in a straight line' technique that many instructors teach may not be the best - after all, you are essentially teaching a student how to do something incorrectly. However, he also warned that instructors shouldn't advocate trailbraking for a new student either - newbies have plenty of other things to worry about. That said, Ross stated that many drivers develop trail braking naturally - and that if that is the case with a student, an instructor shouldn't discourage the trail braking student, provided he's doing the technique properly and for the right corners.
So these are just little snippets of what Ross was discussing. He did spend a whole lot of time on the psychology behind performance driving - how to develop the proper programming, how to integrate your left/right brain functions, and how to get into 'the zone.'
This workshop/seminar was perhaps the best classroom on performance driving I've ever attended. Please share your opinions on these techniques - I am curious to read your reactions...
-Z-man.
01-24-2006, 01:40 PM
#2
Great stuff, Z. THanks for the post.
How did you get Ross signed up for this?? Its something I'd like to investigate for Potomac, now that I have the responsibility to make things happen.
How did you get Ross signed up for this?? Its something I'd like to investigate for Potomac, now that I have the responsibility to make things happen.
01-24-2006, 02:08 PM
#3
Braking does two things...... slows the car for the turn and manages the weight transfer of the car.
Trail braking assists these goals in two ways....
1) Extends braking to allow a later brake point
2) Smooths the transition of weight at turn entry
#1 gets alot of attention, but IMHO, #2 is the more important from a driving standpoint.
in typical turns there ate three weight transitions:
1) To the two front tires as braking is done..
2) From the inside front tire to the outside front tire as car turns iin
3) From inside rear to outside rear as car transitions to steady-state cornering (at apex)
How hard you brake and how much you trailbrake depends on the requirement of weight transition in a particular turn... to be smooth, the speed and degree of weight transition in #1 above (braking) must equal the degree of weight transition in #2 above...(turn-in).
The goal is to keep the weight on the outside front tire exactly the same through all three transitions...
In a sharp turn I need to transition weight quickly, so I brake hard to get the weight to the front quickly, and turn in fast to get the weight to the outside front quickly...
In a fast sweeper, i want transition #2 and #3 to be slow and smooth, so I have to use more gentle braking so as not to transition too much weight to the front.
This is why you should not "crush" the brakes going into a sweeper... this loads up the suspension too much... once I release the brakes, weight rebounds to the back, and makes the car unstable through corner entry.
Trail braking smooths transition #2.... if I need alot of weight transfer quickly (hairpin turn) I trailbrake deep into the turn.... If I want to transfer the weight more slowly (fast weeper) then I use very gentle trailbraking
Trail braking assists these goals in two ways....
1) Extends braking to allow a later brake point
2) Smooths the transition of weight at turn entry
#1 gets alot of attention, but IMHO, #2 is the more important from a driving standpoint.
in typical turns there ate three weight transitions:
1) To the two front tires as braking is done..
2) From the inside front tire to the outside front tire as car turns iin
3) From inside rear to outside rear as car transitions to steady-state cornering (at apex)
How hard you brake and how much you trailbrake depends on the requirement of weight transition in a particular turn... to be smooth, the speed and degree of weight transition in #1 above (braking) must equal the degree of weight transition in #2 above...(turn-in).
The goal is to keep the weight on the outside front tire exactly the same through all three transitions...
In a sharp turn I need to transition weight quickly, so I brake hard to get the weight to the front quickly, and turn in fast to get the weight to the outside front quickly...
In a fast sweeper, i want transition #2 and #3 to be slow and smooth, so I have to use more gentle braking so as not to transition too much weight to the front.
This is why you should not "crush" the brakes going into a sweeper... this loads up the suspension too much... once I release the brakes, weight rebounds to the back, and makes the car unstable through corner entry.
Trail braking smooths transition #2.... if I need alot of weight transfer quickly (hairpin turn) I trailbrake deep into the turn.... If I want to transfer the weight more slowly (fast weeper) then I use very gentle trailbraking
01-24-2006, 02:21 PM
#5
Race Director
Thread Starter
Originally Posted by penguinking
when he talks about your brake ending point, does that also include where to stop braking when in a trail braking situation?
APKhaos - I'll send you a PM/Email with some details.
-Z.
01-24-2006, 02:21 PM
#6
Originally Posted by penguinking
when he talks about your brake ending point, does that also include where to stop braking when in a trail braking situation?
Look at each turn.... start at the apex and work backward to the brake point.... determine how much weight transfer and rotation you need, and adjust your brake-point accordingly.... the braking has to smoothly transition into the turn-in for the turn....
Determine the degree of weight transfer to the outside front tire, and adjust degree of braking to equal that. Less braking will obviously require you to move your brake-point back
determine the point at which full weight transfer to the outside front tire is accomplished.... that is the point at which trail-braking should stop
01-24-2006, 03:01 PM
#7
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i wish i had read this before this weekend 
now i can't practice this new technique until february!
i drive alot on vision, though - most of the time i'm not looking at braking points, so i couldn't tell you where i begin to brake. im looking ahead of the turn to see where i want the car to end up, and so i start my braking based on that. interestingly, i seem to be most consistent when i drive this way. if i watch the ground for brake/turn in/exit points then i get scared and the car tightens up. i have to be constantly looking just under the horizon and ahead to drive comfortably. sorry to hack, but my style seems to be fundamentally different that what was mentioned above.
now i can't practice this new technique until february! i drive alot on vision, though - most of the time i'm not looking at braking points, so i couldn't tell you where i begin to brake. im looking ahead of the turn to see where i want the car to end up, and so i start my braking based on that. interestingly, i seem to be most consistent when i drive this way. if i watch the ground for brake/turn in/exit points then i get scared and the car tightens up. i have to be constantly looking just under the horizon and ahead to drive comfortably. sorry to hack, but my style seems to be fundamentally different that what was mentioned above.
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01-24-2006, 03:44 PM
#8
Race Director
Thread Starter
Penguin - I think it's the combination of both - using visual points in your (close by) periferal vision, as well as looking ahead that make for good technique.
Here's another tid-bit that Ross Bentley also suggested:
During a DE-type session, spend 10 minutes just focusing on the visual sensory input - take your pace down a bit (say 10%) and concentrate on seeing as much of the track as possible. Do this on a track you are familiar with. Look at how the horizon changes, how the car hood bounces up and down, spots on the track, how the track whoosh0es by beside you. Note the various changes in the surface, as well as trackside 'markers' at key points (turnin/apex/trackout) of the track. After the ten minutes, pit, and write down 5 detailed things that you've never noticed before. Next session, do the same thing, only this time taking note of the auditory inputs - perhaps the sound of the wind changing as you slow down - maybe the sound of the exhaust note bouncing off the wall on the side of the track, the sounds that your tires are producing - then write those down. Next, do it with the kinetic inputs (what you feel with your hands, feet, butt...etc.).
What this excersize does is open you up to more sensory input. The more input you have, the better driver you will be. More input means more awareness which leads to more precise driving. You'll start to know when you've slowed down enough for the turn based on the change in sound of the wind whooshing past you, and on the feeling you get in your inner ear that tells you that you've gone from 110 mph down to 80mph, and from the speed at which the braking zone markers are going by beside you, and so on. Also: by focusing on one specific sensory input, you will force yourself to do the other 'stuff' on a more subconcious level.
Here's an interesting thought - the conscious brain can multi-task to the tune of 2,000 bits per second. However, the subconscious mind can handle something like 400,000 bits per second. Why not let your subconcious handle more of the driving? By learning how to take in more sensory input, you will enable your subconcious to do more of the driving for you. At first, taking in more sensory input is a consious effort, but in time, it becomes a subconsious one.
Sound hokey? Try it! Many a driver (and athelete for that matter) have learned to use the subconscious to propel them further than their peers...
-Z.
Here's another tid-bit that Ross Bentley also suggested:
During a DE-type session, spend 10 minutes just focusing on the visual sensory input - take your pace down a bit (say 10%) and concentrate on seeing as much of the track as possible. Do this on a track you are familiar with. Look at how the horizon changes, how the car hood bounces up and down, spots on the track, how the track whoosh0es by beside you. Note the various changes in the surface, as well as trackside 'markers' at key points (turnin/apex/trackout) of the track. After the ten minutes, pit, and write down 5 detailed things that you've never noticed before. Next session, do the same thing, only this time taking note of the auditory inputs - perhaps the sound of the wind changing as you slow down - maybe the sound of the exhaust note bouncing off the wall on the side of the track, the sounds that your tires are producing - then write those down. Next, do it with the kinetic inputs (what you feel with your hands, feet, butt...etc.).
What this excersize does is open you up to more sensory input. The more input you have, the better driver you will be. More input means more awareness which leads to more precise driving. You'll start to know when you've slowed down enough for the turn based on the change in sound of the wind whooshing past you, and on the feeling you get in your inner ear that tells you that you've gone from 110 mph down to 80mph, and from the speed at which the braking zone markers are going by beside you, and so on. Also: by focusing on one specific sensory input, you will force yourself to do the other 'stuff' on a more subconcious level.
Here's an interesting thought - the conscious brain can multi-task to the tune of 2,000 bits per second. However, the subconscious mind can handle something like 400,000 bits per second. Why not let your subconcious handle more of the driving? By learning how to take in more sensory input, you will enable your subconcious to do more of the driving for you. At first, taking in more sensory input is a consious effort, but in time, it becomes a subconsious one.
Sound hokey? Try it! Many a driver (and athelete for that matter) have learned to use the subconscious to propel them further than their peers...
-Z.
Last edited by Z-man; 01-24-2006 at 10:25 PM.
01-24-2006, 06:26 PM
#9
Ross's books were extremely helpful to me.
Although I have never heard him speak, I picked up the "brake-ending point" concept from the books.
My take on what he says is that, basically, there are three main issues you can change by adjusting your braking zone and/or braking pressure (assuming that your basic technique is right).
First, you can begin braking later, which will make the "straight" before the corner longer and potentially increase your entry speed. However, this generally is the least important place to find time on the track, and many new/intermediate drivers brake harder when they brake later (not to mention upsetting the car), which means that their speed through the corner frequently is slower. I definitely have been guilty of this.
Second, you can beneficially affect weight transfer and get the car to rotate better by moving the "brake-ending point" deeper into the corner (i.e., trailbraking). This can increase your speed through the corner, but this technique typically works best in slower corners.
Third, you can increase your entry speed by decreasing the brake pressure you use in the braking zone, which is, or should be, entirely unrelated to where you begin, or even end, braking.
In light of these three considerations, your "brake-ending point" really should be set by the amount of trailbraking you need to accomplish in a particular corner.
Once you determine that, you really do not need to adjust that point. Rather, you can start first working on how much braking you accomplish (i.e., increasing entry speed).
Once you are satisfied with your entry speed, then you can start focusing more upon late braking, with an emphases on not inadvertently overbraking.
I find all of this easier to do if I am focusing on the "brake-ending point," which I got to try at Laguna-Seca with Skip Barber (I am processing video for my trip, and I will post my thoughts as soon as the video is finished).
Too bad I am still slow
Although I have never heard him speak, I picked up the "brake-ending point" concept from the books.
My take on what he says is that, basically, there are three main issues you can change by adjusting your braking zone and/or braking pressure (assuming that your basic technique is right).
First, you can begin braking later, which will make the "straight" before the corner longer and potentially increase your entry speed. However, this generally is the least important place to find time on the track, and many new/intermediate drivers brake harder when they brake later (not to mention upsetting the car), which means that their speed through the corner frequently is slower. I definitely have been guilty of this.
Second, you can beneficially affect weight transfer and get the car to rotate better by moving the "brake-ending point" deeper into the corner (i.e., trailbraking). This can increase your speed through the corner, but this technique typically works best in slower corners.
Third, you can increase your entry speed by decreasing the brake pressure you use in the braking zone, which is, or should be, entirely unrelated to where you begin, or even end, braking.
In light of these three considerations, your "brake-ending point" really should be set by the amount of trailbraking you need to accomplish in a particular corner.
Once you determine that, you really do not need to adjust that point. Rather, you can start first working on how much braking you accomplish (i.e., increasing entry speed).
Once you are satisfied with your entry speed, then you can start focusing more upon late braking, with an emphases on not inadvertently overbraking.
I find all of this easier to do if I am focusing on the "brake-ending point," which I got to try at Laguna-Seca with Skip Barber (I am processing video for my trip, and I will post my thoughts as soon as the video is finished).
Too bad I am still slow
01-24-2006, 07:20 PM
#10
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The braking techniques ring true. I find the approach described to be more natural or more easily accomplished. I read Ross's book last year and highly reccommend them. I like the emphasis on goal and awareness. It was very helpful.
01-24-2006, 08:11 PM
#12
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Originally Posted by Z-man
instead of focusing on the starting point of the brake zone, Ross Bentley suggests that the driver look further down track and focus on the brake ending zone - or somewhere around the turn in point of the corner. By focusing on this, and programming your driving on the track to adjust your braking based on this reference point, Ross argues that the braking will become more consistent.
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
01-24-2006, 08:41 PM
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Originally Posted by APKhaos
Great stuff, Z. THanks for the post.
How did you get Ross signed up for this?? Its something I'd like to investigate for Potomac, now that I have the responsibility to make things happen.
How did you get Ross signed up for this?? Its something I'd like to investigate for Potomac, now that I have the responsibility to make things happen.
see you on the track
01-24-2006, 10:16 PM
#15
Race Director
Thread Starter
I don't have his presentation in written format (but you can buy his books!)
I did video tape the whole day (yes, Ross gave me permission!) - and will probably try to cut it to DVD - if I find someone with a VHS to DVD machine...
I agree Arlene - Mr. Bentley has amazing knowledge on the subject we all love, he has terrific presentation skills, and he has a passion for this beyond compare. He stated that between racing and coaching, he had over 200 track days in 2005 alone. Man, that's a lot of seat time!
-Z-man.
I did video tape the whole day (yes, Ross gave me permission!) - and will probably try to cut it to DVD - if I find someone with a VHS to DVD machine...
Originally Posted by tntporsche
Ross was probably the best speaker that I have ever heard. I hope we can get him back next year . . .
-Z-man.