???..about the 'new' corner technique...
01-20-2011, 09:57 AM
#16
Addict
Rennlist Member
Rennlist Member
Patrick - this style description doesn't conflict with what I aim to achieve in my 924... so I wouldn't say it's a result of the cars your instructor is used to driving... just the fast way. 
I arrived at this driving style not through instruction or discussion, but just by a conscious choice to try something different... that happened to be faster, when I thought it'd be slower! Unexpected, but I had data, and data never lies!
Also - speaking to Mark's point #4 - I found I couldn't easily learn this in my racecar. But I quickly learned it in go-karts, as they won't turn without heavy trail-braking due to the solid rear axle. However, since they spin so easily (rear brake only), it really teaches finesse with the brake and how to slide the car controllably on the brakes... Plus it's a zero-risk environment (open lapping), so you take those chances...
I arrived at this driving style not through instruction or discussion, but just by a conscious choice to try something different... that happened to be faster, when I thought it'd be slower! Unexpected, but I had data, and data never lies!
Also - speaking to Mark's point #4 - I found I couldn't easily learn this in my racecar. But I quickly learned it in go-karts, as they won't turn without heavy trail-braking due to the solid rear axle. However, since they spin so easily (rear brake only), it really teaches finesse with the brake and how to slide the car controllably on the brakes... Plus it's a zero-risk environment (open lapping), so you take those chances...
01-20-2011, 10:35 AM
#17
Race Director
... Alternatively I guess you could brake more lightly but for long enough to trail into corner entry...or brake earlier and lighter and coast into corner entry at a high-ish speed and brake again with trail. The Pro was trying to get me to come off the brakes more softly so as to retain better balance. Therefore I think he braked more softly on and off, earlier and for a bit longer which enabled him to drive through and out of the corner with more speed than me. I tended to brake later with more speed and get off the brakes faster and more abruptly, so the potential for me to spin or lose corner drive speed was apparent.
When you trail brake you ease off the brakes gently so that you do not upset the balance of the car. This can make it feel like costing when in fact you modulating the brake pedal. This modulation is REQUIRED to be able to brake and turn.
Even in straight line brake a brake pressure curve should ramp up very fast at application and then slowly release as your forward load decreases eventully bleeding off to nothing. At which point you start applying throttle to get out of the turn.
01-20-2011, 12:15 PM
#18
Rennlist Member
It seems that "rolling into the corner" is essentially the same idea, but for weight transfer to the side. Progressively ask the car for more cornering force as the weight is being smoothly transitioned to the outside (keeping the car balanced).
01-20-2011, 12:53 PM
#19
Rennlist Member
Even the brake "ramp up" will work best when coordinated with the weight transfer of the car (spring rates, CG placement and shock settings). A softer car can not reach peak braking Gs as fast as a stiff car. The weight transfer puts more weight on the front wheels and makes it harder to lock the wheels up. If you stab the brake pedal too fast, you might lock the wheels up - but, that same brake pressure with a fully loaded front end won't lock the wheels up - in fact you can probably apply more pressure now.
It seems that "rolling into the corner" is essentially the same idea, but for weight transfer to the side. Progressively ask the car for more cornering force as the weight is being smoothly transitioned to the outside (keeping the car balanced).
It seems that "rolling into the corner" is essentially the same idea, but for weight transfer to the side. Progressively ask the car for more cornering force as the weight is being smoothly transitioned to the outside (keeping the car balanced).
all that is a bit counter intuitive of what has to be done to 'make suspension work' plus i am not sure i simply understand it all correctly.
01-20-2011, 01:29 PM
#20
Three Wheelin'
Interesting. Here are some comments:
1. I try to teach students that there is an ideal line around a racing track. Geometric apexes defined by the widest possible arcs. Everything else we do is a trade-off based on the fact that the car is not a perfect object of physics. I go for geometric apexes in most corners. Exceptions are obvious puzzle pieces where what comes before and/or after creates an appropriate deviation.
2. I encourage students to understand what happens if we are on the limit and go too early or too late. I use the illustration from the Skip Barber video. They get it and see the merits of approaching the limits while deliberately choosing geometric or late apexes.
3. In my experience, students do not overslow based on instructors recommending slow in, fast out. They overslow because they do not know how much slowing they need to be on the limit.
4. I never work on entry speed. I always encourage students to work toward the limit by losing less speed, as opposed to increasing entry speed, or braking later. Subtle difference that seems to work for me with students.
5. I like to teach students that threshold braking is using all of the vehicle's braking capabilities. And we discuss the places where it makes sense and, as applicable, the few places where it does not.
6. If I have a student that is doing well and getting close to limits, then we discuss the fact that there is exit real estate left, by definition. So we discuss that a wider arc is possible, therefore greater speed, and we back up the chosen apex accordingly.
I have not read all of the threads about rolling the car and weight transfer and all of that. But I wouldn't begin to discuss any of that with a student or even an experienced driver that doesn't have a handle on the basics. All of that weight transfer stuff has a lot of basic theory behind it, but its application is very car and car-type specific. For example, what I do with weight in my 1950 pound 911 on slicks is different from what a gal might do in her 3000 pound GT3.
1. I try to teach students that there is an ideal line around a racing track. Geometric apexes defined by the widest possible arcs. Everything else we do is a trade-off based on the fact that the car is not a perfect object of physics. I go for geometric apexes in most corners. Exceptions are obvious puzzle pieces where what comes before and/or after creates an appropriate deviation.
2. I encourage students to understand what happens if we are on the limit and go too early or too late. I use the illustration from the Skip Barber video. They get it and see the merits of approaching the limits while deliberately choosing geometric or late apexes.
3. In my experience, students do not overslow based on instructors recommending slow in, fast out. They overslow because they do not know how much slowing they need to be on the limit.
4. I never work on entry speed. I always encourage students to work toward the limit by losing less speed, as opposed to increasing entry speed, or braking later. Subtle difference that seems to work for me with students.
5. I like to teach students that threshold braking is using all of the vehicle's braking capabilities. And we discuss the places where it makes sense and, as applicable, the few places where it does not.
6. If I have a student that is doing well and getting close to limits, then we discuss the fact that there is exit real estate left, by definition. So we discuss that a wider arc is possible, therefore greater speed, and we back up the chosen apex accordingly.
I have not read all of the threads about rolling the car and weight transfer and all of that. But I wouldn't begin to discuss any of that with a student or even an experienced driver that doesn't have a handle on the basics. All of that weight transfer stuff has a lot of basic theory behind it, but its application is very car and car-type specific. For example, what I do with weight in my 1950 pound 911 on slicks is different from what a gal might do in her 3000 pound GT3.
01-20-2011, 01:32 PM
#21
When Pat drove my car he definitely went to WOT earlier than me. I tried to deduce what was going on though data and video, and what it looks like to me - which may be completely bogus - is that when he's off the brakes, he's on the gas. There is very little free wheeling.
My data and video shows that [in most corners] he releases the brake but then gets to the gas pedal almost immediately. He feeds in a little gas (maybe 1/4-1/2 throttle) for a 1/10 of a second or so, and then he just mats it. In my evaluation, this serves a couple purposes. First, it preps the chassis for gas. One side should already be loaded, so it doesn't need to set for the corner, but some weight does need to transfer to the back. With a race car, this won't take long at all. In my car, it was noticeable. A second purpose is to maintain corner speed - rather than lose speed due to tire scrub - even if only for a fraction of a second. After the weight was shifted, he would just mat it.
Reviewing the data, another substantial difference was trail braking technique. The slope of his LongGs [almost a pun there!] was visibly less steep. If mine was 45º, his was 20º. (I hope I described that right) That is, he was actually on the brakes about the same period of time, but slowing the car in a different manner. His method kept the chassis balanced and utilizing all the grip the tires would give him. I was slowing the car rapidly, and releasing uber slow trying to balance the chassis.
Not sure if this really relates to the original post. But there it is.
-td
My data and video shows that [in most corners] he releases the brake but then gets to the gas pedal almost immediately. He feeds in a little gas (maybe 1/4-1/2 throttle) for a 1/10 of a second or so, and then he just mats it. In my evaluation, this serves a couple purposes. First, it preps the chassis for gas. One side should already be loaded, so it doesn't need to set for the corner, but some weight does need to transfer to the back. With a race car, this won't take long at all. In my car, it was noticeable. A second purpose is to maintain corner speed - rather than lose speed due to tire scrub - even if only for a fraction of a second. After the weight was shifted, he would just mat it.
Reviewing the data, another substantial difference was trail braking technique. The slope of his LongGs [almost a pun there!] was visibly less steep. If mine was 45º, his was 20º. (I hope I described that right) That is, he was actually on the brakes about the same period of time, but slowing the car in a different manner. His method kept the chassis balanced and utilizing all the grip the tires would give him. I was slowing the car rapidly, and releasing uber slow trying to balance the chassis.
Not sure if this really relates to the original post. But there it is.
-td
01-20-2011, 01:35 PM
#22
Three Wheelin'
Sometimes I find that when trying to analyze a transient situation it can be simplest to go back and look at the traction circle. As a driver you will generally be fastest if you can put the car at the edge of the circle in all parts of the track. So for the case here, braking and rolling into the corner, think of it as start at the peak of the circle (12 o'clock). As you're turning into the corner you're rolling off the brakes and you now have some laterally capability, and so as you keep coming off the brakes you can continually add in more steering. Eventually you get to a point where there is little to no braking or throttle, you've got max lat. So essentially with rolling into the corner you're following the outer edge of that circle.
Its like how a lot of PCA instructors used the analogy that you foot is tied to the steering wheel with a string. As you add steering you have to remove brake. I just find it easier to picture on the traction circle to see how I'm using the car. You want to avoid any sharp edges and make yourself a nice round circle.
Its like how a lot of PCA instructors used the analogy that you foot is tied to the steering wheel with a string. As you add steering you have to remove brake. I just find it easier to picture on the traction circle to see how I'm using the car. You want to avoid any sharp edges and make yourself a nice round circle.
01-20-2011, 01:36 PM
#23
Three Wheelin'
I do not believe in momentum cars, momentum tracks or momentum drivers. The track is the track, and the car is the car. The car has certainly inherent capability to get around the track (on the pavement) at the highest possible average speed (by definition the lowest possible lap time). So our job is to use or talents to use as close to 100% of the car's capabilities as possible. No matter whether it is a stock Yugo or a 2011 Formula 1 car from Red Bull. We try to get to 100% every lap, every event. That is our quest.
01-20-2011, 01:41 PM
#24
Three Wheelin'
I love this:
"The very best drivers carry mad speed way deep into the corner (not to be confused with where they may or may not brake in qualifying versus competing for position), make needed corrections to the attitude of the car in the very compressed midcorner/apex area, and than carry this mad speed out again. They may often appear somewhat busy at the wheel on in-car videos....but the car will be serene."
I think those drivers know how much speed is just enough and when and where and how to lose it. This includes dealing with both the tires and the suspension and other aspects of what that vehicle "is." Of course in some forms of racing and in some circumstances, they have, and use, an extra tool... the other fella's car.
"The very best drivers carry mad speed way deep into the corner (not to be confused with where they may or may not brake in qualifying versus competing for position), make needed corrections to the attitude of the car in the very compressed midcorner/apex area, and than carry this mad speed out again. They may often appear somewhat busy at the wheel on in-car videos....but the car will be serene."
I think those drivers know how much speed is just enough and when and where and how to lose it. This includes dealing with both the tires and the suspension and other aspects of what that vehicle "is." Of course in some forms of racing and in some circumstances, they have, and use, an extra tool... the other fella's car.
01-20-2011, 02:10 PM
#28
Race Director
Even the brake "ramp up" will work best when coordinated with the weight transfer of the car (spring rates, CG placement and shock settings). A softer car can not reach peak braking Gs as fast as a stiff car. The weight transfer puts more weight on the front wheels and makes it harder to lock the wheels up. If you stab the brake pedal too fast, you might lock the wheels up - but, that same brake pressure with a fully loaded front end won't lock the wheels up - in fact you can probably apply more pressure now.
It seems that "rolling into the corner" is essentially the same idea, but for weight transfer to the side. Progressively ask the car for more cornering force as the weight is being smoothly transitioned to the outside (keeping the car balanced).
It seems that "rolling into the corner" is essentially the same idea, but for weight transfer to the side. Progressively ask the car for more cornering force as the weight is being smoothly transitioned to the outside (keeping the car balanced).
01-20-2011, 02:18 PM
#29
Race Director
Acceleration and steering a much easier. Even so you cannot have bad steering inputs either as it must also be very good to properly trail brake into a corner.
To be fast at corner entry requres a perfect line, perfect steering input and perfect brake appliction. All of which have to be done very very close to perfect before you really even start the turn else you will be too slow or fly off the track.
01-20-2011, 02:32 PM
#30
Three Wheelin'
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I think I broke this code one day listening to Mario Andretti. He made the statement that most drivers thought the brakes were for slowing the car. He said the brakes are for balancing the car to keep it as smooth as possible through the corner and getting the weight where it needed to be for a particular corner. He'd roll in and I believe just "feather" the throttle to maintain the line he wanted. I can truthfully say it was an epihany to me. He could carry so much more stinking speed into and through the corner than I could, until I finally started using his technique and got somewhat comfortable with it. I tried it on my motorcycle too and it really helped. I was no longer "threshold braking" on every corner, but tuning the track-in, apex, and track out more for each specific corner. He really helped make a big difference in my times.