Trail braking 101
08-16-2010, 12:10 AM
#91
Nordschleife Master
Larry, thanks for asking. It has been very informative.
For every DE I attend, I try to come back with one main take-away, a theme for the event if you wish. A couple of events ago, the "Aha Moment" was: Secret to go Fast = Good/Better Braking
Edit: Maybe I should change my signature now
For every DE I attend, I try to come back with one main take-away, a theme for the event if you wish. A couple of events ago, the "Aha Moment" was: Secret to go Fast = Good/Better Braking
Edit: Maybe I should change my signature now
08-16-2010, 07:59 AM
#92
Mr. Excitement
Rennlist Member
Rennlist Member
I didn't mean for my comments to be a condemnation of PCA (which does a great job of getting drivers from a 1 to a 6 on a scale of 10), but the rather strict and pendantic DE methods sort of indirectly result in what you describe above.
I would describe it like this:
1) new student learns to drive from PCA (which often preaches that more advanced driving techniques like TB and a relatively earlier late apex are "bad")
2) student assimilates into the collective and learns all the driving techniques short of the really advanced "dangerous" stuff.
3) student becomes instructor and propagates the fallacy of "TB is bad," and, thereby, never really learns to drive flat-out.
The students you describe that won't take "advanced" advice have sort of been taught not to take that advice by the PCA system. It's sad really, because there's kind of an attitude of "I've learned it all." And with respect to the PCA dogma, he probably has.
I've instructed with Chin and instructed and raced with PBOC too, and the attitude is definitely more open and willing to learn and teach new/interesting things. I've actually had a national PCA instructor coach (instructor instructor) tell me that trail braking was far too advanced for anyone other than a pro-racer and that it just slowed down all amateurs. Um, yeah, like, totally, wow!
PCA is a fantastic elementary school, but it falls flat on the college prep.
I would describe it like this:
1) new student learns to drive from PCA (which often preaches that more advanced driving techniques like TB and a relatively earlier late apex are "bad")
2) student assimilates into the collective and learns all the driving techniques short of the really advanced "dangerous" stuff.
3) student becomes instructor and propagates the fallacy of "TB is bad," and, thereby, never really learns to drive flat-out.
The students you describe that won't take "advanced" advice have sort of been taught not to take that advice by the PCA system. It's sad really, because there's kind of an attitude of "I've learned it all." And with respect to the PCA dogma, he probably has.
I've instructed with Chin and instructed and raced with PBOC too, and the attitude is definitely more open and willing to learn and teach new/interesting things. I've actually had a national PCA instructor coach (instructor instructor) tell me that trail braking was far too advanced for anyone other than a pro-racer and that it just slowed down all amateurs. Um, yeah, like, totally, wow!
PCA is a fantastic elementary school, but it falls flat on the college prep.
08-16-2010, 09:19 AM
#93
Rennlist Member
Nope. This why you need to learn to heel and toe. In some corner you must brake hard, turn and down shift all at the same time.
So you must master heel and toe downshift as that allows you do the downshift as you are braking. This a fundamental skill.
Once mastered you can throw turn while braking in the mix as well.
When you execute the down change depends on RPM. If youi have long corner entry you will find the need to brake during corner entry and also be downshift as well.
One classic corner we have at a local track goes like this.
Entry is down the main straight. 115 mph in 944 spec or maybe 140 in fast high hp car.
For the 944 we wait till the last moment get on the brakes hard in straight line downshift then turn in while still braking. Downshift to 4th while still braking down to the apex. Then once slow down eniugh at near the apex downshift again to 3rd and get right back on the gas. Done right we will be turning 5000+ rpm in 3rd and full throttle all the way out of the corner. Of course we are al the limit of grip all the way around corner entry. I would guess 10% of speed reduction is done in straight line. The rest is all after turn in with a significant cornering load on the chassis.
If we were just braking in straight line we would have probabyl 7-8 car lengths of neutral throttle at 4500 rpm in 3rd and maybe 65 mph. And of couse be passed like we a standing still as turn in speed is probaby right about 95 or 100 mph by using trail braking. Min apex speed is probably 70 mph.
The other cool thing about trail braking is done well you can run a faster apex speeds since you can use the weight transfer off the rearend to make the car turn. It sort of feels like a controlled spin in the way you can get the back end ot rotate.
Trail braking is very powerfull skill and really seperates the men from the boys in track driving. Winning races and getting fast laps does not occur on straight aways, or corner exit. Those areas to pretty easy for any one to master. Even mid corner is not too hard. However braking and corner entry are hard to do and that makes then the place races are won and lost. Even with pros most drivers make a mistake not on corner exit, but at corner entry. Even if they go off on corner exit it was because of a mistake going into the corner.
That said you cannot let corner entry speed degrade corner exit speed. Slow in fast out is good for DE. However in race you need fast in and fast out. The challenge is that fast in done wrong means slow out. Getting it right is a very delicate balance.
So you must master heel and toe downshift as that allows you do the downshift as you are braking. This a fundamental skill.
Once mastered you can throw turn while braking in the mix as well.
When you execute the down change depends on RPM. If youi have long corner entry you will find the need to brake during corner entry and also be downshift as well.
One classic corner we have at a local track goes like this.
Entry is down the main straight. 115 mph in 944 spec or maybe 140 in fast high hp car.
For the 944 we wait till the last moment get on the brakes hard in straight line downshift then turn in while still braking. Downshift to 4th while still braking down to the apex. Then once slow down eniugh at near the apex downshift again to 3rd and get right back on the gas. Done right we will be turning 5000+ rpm in 3rd and full throttle all the way out of the corner. Of course we are al the limit of grip all the way around corner entry. I would guess 10% of speed reduction is done in straight line. The rest is all after turn in with a significant cornering load on the chassis.
If we were just braking in straight line we would have probabyl 7-8 car lengths of neutral throttle at 4500 rpm in 3rd and maybe 65 mph. And of couse be passed like we a standing still as turn in speed is probaby right about 95 or 100 mph by using trail braking. Min apex speed is probably 70 mph.
The other cool thing about trail braking is done well you can run a faster apex speeds since you can use the weight transfer off the rearend to make the car turn. It sort of feels like a controlled spin in the way you can get the back end ot rotate.
Trail braking is very powerfull skill and really seperates the men from the boys in track driving. Winning races and getting fast laps does not occur on straight aways, or corner exit. Those areas to pretty easy for any one to master. Even mid corner is not too hard. However braking and corner entry are hard to do and that makes then the place races are won and lost. Even with pros most drivers make a mistake not on corner exit, but at corner entry. Even if they go off on corner exit it was because of a mistake going into the corner.
That said you cannot let corner entry speed degrade corner exit speed. Slow in fast out is good for DE. However in race you need fast in and fast out. The challenge is that fast in done wrong means slow out. Getting it right is a very delicate balance.
08-16-2010, 09:54 AM
#94
Race Car
fwiw, I start teaching trail braking with left foot braking on turns that do not need a downshift. (like the carousel at sebring). if they are ready for left foot braking, then they can master trail braking. (and heel and toe, etc...)
(by that time, they have already mastered threshold braking, and can continue to brake hard, while down****ing... ie not releasing any brake as the clutch goes in and out.)
a DE is a great introduction to track events. I sure wish they existed when was starting out...
(by that time, they have already mastered threshold braking, and can continue to brake hard, while down****ing... ie not releasing any brake as the clutch goes in and out.)
a DE is a great introduction to track events. I sure wish they existed when was starting out...
08-16-2010, 10:16 AM
#95
Three Wheelin'
The other cool thing about trail braking is done well you can run a faster apex speeds since you can use the weight transfer off the rearend to make the car turn. It sort of feels like a controlled spin in the way you can get the back end ot rotate.
Trail braking is very powerfull skill and really seperates the men from the boys in track driving. Winning races and getting fast laps does not occur on straight aways, or corner exit. Those areas to pretty easy for any one to master. Even mid corner is not too hard. However braking and corner entry are hard to do and that makes then the place races are won and lost. Even with pros most drivers make a mistake not on corner exit, but at corner entry. Even if they go off on corner exit it was because of a mistake going into the corner.
That said you cannot let corner entry speed degrade corner exit speed. Slow in fast out is good for DE. However in race you need fast in and fast out. The challenge is that fast in done wrong means slow out. Getting it right is a very delicate balance.
Trail braking is very powerfull skill and really seperates the men from the boys in track driving. Winning races and getting fast laps does not occur on straight aways, or corner exit. Those areas to pretty easy for any one to master. Even mid corner is not too hard. However braking and corner entry are hard to do and that makes then the place races are won and lost. Even with pros most drivers make a mistake not on corner exit, but at corner entry. Even if they go off on corner exit it was because of a mistake going into the corner.
That said you cannot let corner entry speed degrade corner exit speed. Slow in fast out is good for DE. However in race you need fast in and fast out. The challenge is that fast in done wrong means slow out. Getting it right is a very delicate balance.
Your point about "men from the boys" explains why 90% of competitive passing (even at the pro level; even at F1) occurs under braking at corner entry.
08-16-2010, 10:22 AM
#96
Three Wheelin'
Larry, thanks for asking. It has been very informative.
For every DE I attend, I try to come back with one main take-away, a theme for the event if you wish. A couple of events ago, the "Aha Moment" was: Secret to go Fast = Good/Better Braking
Edit: Maybe I should change my signature now
For every DE I attend, I try to come back with one main take-away, a theme for the event if you wish. A couple of events ago, the "Aha Moment" was: Secret to go Fast = Good/Better Braking
Edit: Maybe I should change my signature now
After the first few DEs, we all learn by connecting dots:
1) brake in a straight line
2) turn in
3) adjust your line a bit if not correct
4) start to apply a little throttle and apex
5) apply more throttle and let the car drift to trackout.
In reality, all 5 of these things should happen in a continuous, rather than discreet, manner. The best way to accomplish such goal is to look up and keep your eyes and attention focused down the track. Your feet and hands will follow automatically once you stop focusing on "now I need to brake, now I need to turn, etc."
08-16-2010, 10:32 AM
#97
Three Wheelin'
While PCA may not have an official policy, it's sort of left at the beginner level as a big no-no and never officially addressed again (at least with the 5 or 6 regions I've instructed with).
I would guess close to half of PCA instructors don't regularly use/teach TB, but that's a total SWAG.
PCA also doesn't stress continuing education as much as clubs like Chin. Chin REALLY encourages ride sharing. At a Chin event, you'll see instructors driving novices, intermediate students driving instructors and all levels in between. PCA generally discourages rides except for instructor/novice, and even then tells instructors to go slowly in the green/blue group with students so the students don't get crazy with trying to go fast. There's just a different attitude within PCA that's a lot more pedantic. They didn't even allow instructors to pass in the corners until they were pretty much forced to by instructors leaving for clubs with fewer "you are a child and need to follow the rules" rules.
08-16-2010, 10:35 AM
#98
Race Director
That's interesting Joe as I was reading up to your post in this thread and it appeared as if trail + heel/toe through a corner was a no no. So I immediately was thinking of a particular turn that I do this on and also thought, gee I must be going too slow if I can do that and not upset the balance of the car. I do this and then get straight into Maintenance throttle. It's a double apex off camber corner which is kinda strange and patience is the key. I also thought that this may exemplify the prime differences between front and rear engined cars too perhaps?
08-16-2010, 10:53 AM
#99
Race Director
I would phrase it a little differently. Rather than focus on "maximum braking;" try to focus on feeling how much speed you can carry into the turn. Let the braking become secondary to your sense of speed into the turn, and the proper rate of braking will happen automatically.
This puts braking as tool to slow the car enough to make the corner rather than braking as way to say "man I have great brakes".
So when I am braking for a corner the goal is not max braking, but slowing the car to achieve max cornering power. Some times than means braking earlier and lighter to make sure the is balanced going into the corner. If I brake too late I can spend alot of time gathering up the car after the braking zone and thus makes my apex speed slower.
08-16-2010, 11:10 AM
#100
Race Car
This thread has been a great read. TB is a skill I've personally been working on this year and thought I thought I did my homework before working on it at the track, there has been some great stuff in this thread that I will try to apply as I attempt to further master this skill set.
A great tool for me has been studying in-car footage from myself vs. pro's at the same track. Realizing that despite the fact that I feel as though I'm holding break pressure further into the corner I'm still slowed and back to maintenance throttle pretty early compared to some recent in-car I've seen from the same track. I'll slowly continue to work up to scrubbing speed to apex without scrubbing soo much that I'm loosing exit speed as a result. It's a gradual process but one which I fell will pay off when I finally get it down.
Oh yeah, and attempting to learn in a bit more of an idiot proof car (m3) helps too.
A great tool for me has been studying in-car footage from myself vs. pro's at the same track. Realizing that despite the fact that I feel as though I'm holding break pressure further into the corner I'm still slowed and back to maintenance throttle pretty early compared to some recent in-car I've seen from the same track. I'll slowly continue to work up to scrubbing speed to apex without scrubbing soo much that I'm loosing exit speed as a result. It's a gradual process but one which I fell will pay off when I finally get it down.
Oh yeah, and attempting to learn in a bit more of an idiot proof car (m3) helps too.
08-16-2010, 11:23 AM
#101
Three Wheelin'
The only difference is that with a high HP car, it's a LOT harder. Say you and I have the same suspension and tires and can generate the same amount of lateral grip which is maxed at 60mph at the turn at the crest of the back straight at VIR. In your 944, you have to nail your braking point just right to go from 115/120 to 60 in the smallest window possible. In my GT2, I'm going about 170 and have to brake to the same 60mph.
08-16-2010, 01:15 PM
#102
Rennlist Member
Thread Starter
This is really good advice whether you are driving a slow car or a fast car. Learning to manage momentum and speed into the turn are what it's all about, even with 600hp.
The only difference is that with a high HP car, it's a LOT harder. Say you and I have the same suspension and tires and can generate the same amount of lateral grip which is maxed at 60mph at the turn at the crest of the back straight at VIR. In your 944, you have to nail your braking point just right to go from 115/120 to 60 in the smallest window possible. In my GT2, I'm going about 170 and have to brake to the same 60mph.
The only difference is that with a high HP car, it's a LOT harder. Say you and I have the same suspension and tires and can generate the same amount of lateral grip which is maxed at 60mph at the turn at the crest of the back straight at VIR. In your 944, you have to nail your braking point just right to go from 115/120 to 60 in the smallest window possible. In my GT2, I'm going about 170 and have to brake to the same 60mph.
08-16-2010, 01:45 PM
#103
In your example corner, you would bleed off speed in a straight line from 150 to around 60 MP or so (maybe higher, but you get the idea that it is just north of typical entry speed). Then start your trailing braking. You can feel if the car is going too fast at entry [which it probably will be since it is a 50 MPH entry]. I call it the twitchies. BUT, since you are trailing, you will gradually get the car slowed and set to its correct mid-corner speed. In this example, being so close to corner entry speed, the car will probably take a set closer to turn-in than apex, and then you simply transition to gas.
But, if you are carried in too much speed, you can just trail brake longer into the corner until the car gets the correct midcorner speed and takes a set. Basically, you have a built in "buffer zone" - as long as you didn't really overcook the entry speed. If you are going too slow, you just transition to gas earlier in the corner. If you are braking past the apex, well, that's just too much speed on entry.
I hope I described that understandably.
-td
08-16-2010, 02:37 PM
#104
Nordschleife Master
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We haven't talked much about weight transfer in a TB application, what TD described above as "taking a set". You can feel the set, when the car transfers weight to the front and outside tires. That's the exact point you want to transition back to the throttle. How quickly and powerfully depends on the corner and the car, but you usually want to go throttle up at that point and start unwinding the wheel.....
