Your diagram was the preferred method everyone was taught to do turns 17-18-19 at Calabogie. We open wheel racers quickly found entering on the inside and apexing earlier was the faster line.
The two biggest things I learned from you and that I stress most when instructing (particularly with beginners) in terms of focus and conscious thought in race conditions are vision control and braking, specifically the release points (Begin release -> Complete release) and rate of said release of the brake pedal/pressure. I stress those two as most worthy of active attention at speed with vision control being nearly 85% (hmmm or maybe 84%..? ;P) and much of the remaining mental load capacity being on quick self-checks on how well you're balancing/rotating the car into and through the apex via smooth/assertive brake release.
Lately with my current protégé I've ruminated on the very small number of "hard" rules in terms of racing technique as you progress down The Path.. (closest I'd wager is the car going where your vision guides it, hence stressing it SO much), sometimes to go REALLY quick you actually may have to do the exact
OPPOSITE of traditional thinking. The prime example being braking/turn-in; common knowledge says you want to brake late and hard, and turn-in late for a late apex -> early exit -> etc... but then of course there's telemetry out there of some of the absolute greatest drivers ever gaining time against their teammates by braking *earlier and with less force*! (!!) AND beginning the rotation almost unfathomablly eary while still nailing the apex and exit!..!
...Now my comments are always tangential rants so I'll try to reign it in now and not reiterate everything your post and follow-up detail on WHY that sometimes is, but an example I find myself enjoying more and more as my own eye develops is watching the last two corners of laps on Top Gear's Star in a Reasonably Priced Car segment. It's phenomenal practice for coaching and driving to watch, compare, analyze and critique the average Joe's attempts, but then to compare that to when they give the F1 guys a go.. holy mother, I can never hold back a yelp of excitement when they send it into the penultimate corner an then through Gambon. I urge anyone who gets to the bottom of this comment to go see how early they turn in while still nailing a 'late' apex immediately, clearly you've got time on your hands!
I’ve been trying to practice something like this for a while, but I’ve got a mental program that insists I can’t start turning the wheel until after I’ve begun releasing the brakes. My traction circle is more like a diamond. Any tips for reprogramming?
Think of it this way: you're using 100% of the tires's traction when braking in a straight line; as you begin turning the steering wheel into the corner you trade off some of that braking traction for cornering - when you just begin turning in you're asking for, let's say, 10% of that traction for cornering, and 90% for braking; then 50% for cornering and 50% for braking; then 75% for cornering and 25% for braking; and eventually 100% for cornering and 0% for braking. Obviously, that doesn't happen in steps like this, but rather a smooth transition. So, you absolutely can turn the steering wheel while braking because you never go from 0% cornering to 100% cornering in an instant - it takes time (in our sport, this is a small amount of time, but it's still time) to build up to using all 100% of the tires's traction for cornering. You might as well be using the un-used percentage for braking while building up to 100% cornering traction.
That's the theory, and a good way of re-programming your mind into believing and knowing that you can, for sure, turn the steering wheel while slowly releasing the brakes. In reality, there are some subtle variations on this, and times where you might deliberately want to go over that 100% in one force direction, but that's not what we're talking about here.
Oh, and then you have to factor in load transfer because the 100% traction limit for one tire (or one pair of tires) will be different from the others. That's mostly what I'm talking about in my article - by keeping more load on the front, and less on the rear, the rear tires have less overall grip. By managing the TIMING AND RATE OF RELEASE OF THE BRAKES, you can manage the amount of rotation.
Braking while turning decreases the friction to the back wheels thus giving them the opportunity to slip/slide the back and thus rotate the car - is that what you are saying? That is a skill I have to improve as a little slide becomes a big slide in a heart beat. I love the concept...now need to learn to execute with confidence.
Yes, with more load on the front tires, and less on the rear, the slip angle of the rear will be greater. Think of this as "controlled, deliberate oversteer." I think of rotation as oversteer that I'm causing; oversteer that the car causes (due to the car's setup) is a different kind of oversteer. Yes, it takes practice, but you'll find that a little slide does not become a big slide in a heart beat if you're deliberately causing it. When slides turn into big slides in a heart beat is when you're not expecting them; if you're deliberately generating the rotation, you're expecting it, and it's relatively easy to control.
There are no tricks! :) I’m going to write more about this soon, but when you first start working on trail braking more, you over-slow the car, right? It makes sense since you’re hanging on the brakes longer. So it’s important to think about the “brake zone,” and shifting the entire zone in when trail braking more. That’ll keep min speed up while enabling you to use trail braking to rotate the car. We tend to think of the begin of braking (BoB) as a point, and even the end of braking (EoB) as a point, but we need to think about what happens in between as the zone that we can shift forward and back.
As always, I look forward to your writing. To clarify (I hope), I was referring to increasing the rate of release of the brake in the corner - beyond my comfort level - with the aim of increasing the min speed. The fear is losing grip. The benefit is finding more speed to ‘roll’ or float with mid-corner and setting up that 1 or 2 mph more exit speed than I know I can, to begin building on that speed for the straight. An engineer can compute the max speed, I;d bet, for a given turn and it’s surface condition, dry or wet. I won’t have that mph figure in my head at that moment in time, and even if I did, I;m not sure I could glance down in that moment to find it on the AIM dash. I am looking forward to working on this challenge, and more, in the upcoming season. Thanks for doing what you do, Ross, sharing it with all of us.
Good stuff Ross. I’ve started telling (teaching) my students that the brakes (the fine tuning of their use) is the key to being fast(er) at the track! Thx👊
I tracked an E30 M3 for over a decade and they have to be driven with a high rear slip angle. A couple of us worked with Seth Thomas who coached us to do what you described. Now I'm driving an E36 and it's a little harder to achieve the same results
Struggling with "rotation" - my brain doesn't believe me when I tell it something unless I can explain why. It would seem that releasing the brakes takes weight off the front and places it the only other place it has to go...to the rear. Correct? If so, how does that help increase yaw? Since the timing of the release seems critical is it because the car becomes unsettled and a tiny bit of traction comes off the rear as a result?
You’re absolutely right that releasing the brake unloads the front tires, and that usually reduces rotation. What I was saying was that I was delaying the release of the brakes - extending trail braking - and that’s why this increased rotation. Make sense?
The key is what’s happening with the tire. The time constant of braking is smaller (think “faster”) than the time constant of the bigger/heavier springs/dampers. So, when the “fast” brakes are released, the tires suddenly are asked to do less and give more to turning traction before the “slow” weight has transitioned to the rear... meanwhile (we’re talking split seconds) the front grips more and thus rotates the car. It’s like riding a wave with the brake pedal balancing the braking and turning grip.
This is not what I'm talking about. I'm talking about a long, slow release of the brakes to keep the front tires loaded, and the rear tires less loaded. That's what causes the rotation, not a fast release of the brakes. A fast release of the brakes usually results in understeer, not oversteer/rotation.
To coin a phrase, "Aha!". So in those split seconds the front tire gains grip BEFORE the load transfer moves to the rear, thus increasing yaw and we get rotation.
Thinking further, the more rapidly I release the brakes at the right moment the greater the effect? A paradigm example would be to "snap" the brakes off and the car would spin like a top?
I think my brain is beginning the understand the "why" behind the relationship between brake release and rotation. Thank you times a million. Now to put it into action....a little at a time.
No, that's not it. Snapping your foot off the brakes unloads the front tires and will likely (but not always) induce understeer, not rotation. It's the SLOW release of the brakes that keeps the front tires loaded that causes the rotation. If you snap your foot off the brakes, the front unloads, load goes to the rear, and the rear gains grip - so less rotation. Snapping your foot off the brakes will not cause the car to spin like a top. It's most likely to cause the car to plough or push almost straight ahead, and not rotate.
it is possible to overload the front tires with too much trail braking, but that is definitely not what I'm talking about in this article. I'm talking about keeping load on the front tires with a long, slow release of the brakes - trail braking a lot - keeping load on the front tires and unloading the rear tires so the car rotates a lot.
Ross, thanks for taking the time on this. I've written and erased four different responses to your comment over the past half hour because all of them would ultimately shine a brighter light on my ignorance. Maybe it will be easier to discuss in person next week at my favorite track and then I can add a chapter on rotation to my upcoming book "Performance Driving for the Completely Stupid". :)
OK, so further down the rabbit hole. In my quest to understand the "why" I found Andre Marziali's "Physics of Racing" on YouTube. At 31:55 in his video he explains the forces at play during trail braking, and along with everything I (mostly) already knew he added in the effect of the front suspension unloading. Using sample calculations it shows that the springs increase force without respect to mass when unloading AND that the rear loses force at a disproportional rate because it was under less load to begin with. Perhaps this is what I've been missing when trying to understand why load transfer from front to rear helps rotation. More study is needed.
I've come to believe my efforts to understand the "why" of rotation are bass-akwards. It's not about what the release of brakes is doing, it's what you're NOT doing if releasing them earlier. You're NOT transferring load to the rear prematurely which would prevent rotation. Hence the importance of "timing and rate".
Your diagram was the preferred method everyone was taught to do turns 17-18-19 at Calabogie. We open wheel racers quickly found entering on the inside and apexing earlier was the faster line.
Yeah, this is brilliant Ross ... I’m doing the math in my head about how many times I’d have to try it before I got it right. Fantastic description.
More than once?
Ross , in order to accomplish effective trail braking , I really need to be good at left foot braking ? Thanks
No, not really. One can trail brake with either right or left foot. I was only right foot braking in the story here.
God, I love this!
The two biggest things I learned from you and that I stress most when instructing (particularly with beginners) in terms of focus and conscious thought in race conditions are vision control and braking, specifically the release points (Begin release -> Complete release) and rate of said release of the brake pedal/pressure. I stress those two as most worthy of active attention at speed with vision control being nearly 85% (hmmm or maybe 84%..? ;P) and much of the remaining mental load capacity being on quick self-checks on how well you're balancing/rotating the car into and through the apex via smooth/assertive brake release.
Lately with my current protégé I've ruminated on the very small number of "hard" rules in terms of racing technique as you progress down The Path.. (closest I'd wager is the car going where your vision guides it, hence stressing it SO much), sometimes to go REALLY quick you actually may have to do the exact
OPPOSITE of traditional thinking. The prime example being braking/turn-in; common knowledge says you want to brake late and hard, and turn-in late for a late apex -> early exit -> etc... but then of course there's telemetry out there of some of the absolute greatest drivers ever gaining time against their teammates by braking *earlier and with less force*! (!!) AND beginning the rotation almost unfathomablly eary while still nailing the apex and exit!..!
...Now my comments are always tangential rants so I'll try to reign it in now and not reiterate everything your post and follow-up detail on WHY that sometimes is, but an example I find myself enjoying more and more as my own eye develops is watching the last two corners of laps on Top Gear's Star in a Reasonably Priced Car segment. It's phenomenal practice for coaching and driving to watch, compare, analyze and critique the average Joe's attempts, but then to compare that to when they give the F1 guys a go.. holy mother, I can never hold back a yelp of excitement when they send it into the penultimate corner an then through Gambon. I urge anyone who gets to the bottom of this comment to go see how early they turn in while still nailing a 'late' apex immediately, clearly you've got time on your hands!
I’ve been trying to practice something like this for a while, but I’ve got a mental program that insists I can’t start turning the wheel until after I’ve begun releasing the brakes. My traction circle is more like a diamond. Any tips for reprogramming?
Think of it this way: you're using 100% of the tires's traction when braking in a straight line; as you begin turning the steering wheel into the corner you trade off some of that braking traction for cornering - when you just begin turning in you're asking for, let's say, 10% of that traction for cornering, and 90% for braking; then 50% for cornering and 50% for braking; then 75% for cornering and 25% for braking; and eventually 100% for cornering and 0% for braking. Obviously, that doesn't happen in steps like this, but rather a smooth transition. So, you absolutely can turn the steering wheel while braking because you never go from 0% cornering to 100% cornering in an instant - it takes time (in our sport, this is a small amount of time, but it's still time) to build up to using all 100% of the tires's traction for cornering. You might as well be using the un-used percentage for braking while building up to 100% cornering traction.
That's the theory, and a good way of re-programming your mind into believing and knowing that you can, for sure, turn the steering wheel while slowly releasing the brakes. In reality, there are some subtle variations on this, and times where you might deliberately want to go over that 100% in one force direction, but that's not what we're talking about here.
Oh, and then you have to factor in load transfer because the 100% traction limit for one tire (or one pair of tires) will be different from the others. That's mostly what I'm talking about in my article - by keeping more load on the front, and less on the rear, the rear tires have less overall grip. By managing the TIMING AND RATE OF RELEASE OF THE BRAKES, you can manage the amount of rotation.
Braking while turning decreases the friction to the back wheels thus giving them the opportunity to slip/slide the back and thus rotate the car - is that what you are saying? That is a skill I have to improve as a little slide becomes a big slide in a heart beat. I love the concept...now need to learn to execute with confidence.
Yes, with more load on the front tires, and less on the rear, the slip angle of the rear will be greater. Think of this as "controlled, deliberate oversteer." I think of rotation as oversteer that I'm causing; oversteer that the car causes (due to the car's setup) is a different kind of oversteer. Yes, it takes practice, but you'll find that a little slide does not become a big slide in a heart beat if you're deliberately causing it. When slides turn into big slides in a heart beat is when you're not expecting them; if you're deliberately generating the rotation, you're expecting it, and it's relatively easy to control.
My current challenge is,*getting off the brakes faster* to allow more mid-corner speed.
Any tricks to this? I am thinking kind-of the inverse of ‘putting your left foot on top of your right foot going into The Kink”.
There are no tricks! :) I’m going to write more about this soon, but when you first start working on trail braking more, you over-slow the car, right? It makes sense since you’re hanging on the brakes longer. So it’s important to think about the “brake zone,” and shifting the entire zone in when trail braking more. That’ll keep min speed up while enabling you to use trail braking to rotate the car. We tend to think of the begin of braking (BoB) as a point, and even the end of braking (EoB) as a point, but we need to think about what happens in between as the zone that we can shift forward and back.
As always, I look forward to your writing. To clarify (I hope), I was referring to increasing the rate of release of the brake in the corner - beyond my comfort level - with the aim of increasing the min speed. The fear is losing grip. The benefit is finding more speed to ‘roll’ or float with mid-corner and setting up that 1 or 2 mph more exit speed than I know I can, to begin building on that speed for the straight. An engineer can compute the max speed, I;d bet, for a given turn and it’s surface condition, dry or wet. I won’t have that mph figure in my head at that moment in time, and even if I did, I;m not sure I could glance down in that moment to find it on the AIM dash. I am looking forward to working on this challenge, and more, in the upcoming season. Thanks for doing what you do, Ross, sharing it with all of us.
Thanks. Now I can't get the Simon n Garfunkel song out of my head.
(I've had worse tho!)
Ps- see? I do read you. #noregrats
Good stuff Ross. I’ve started telling (teaching) my students that the brakes (the fine tuning of their use) is the key to being fast(er) at the track! Thx👊
Yup!
I tracked an E30 M3 for over a decade and they have to be driven with a high rear slip angle. A couple of us worked with Seth Thomas who coached us to do what you described. Now I'm driving an E36 and it's a little harder to achieve the same results
Love the E30. And it was an E36 that I was driving in my story here.
🤯 I have a few things to think about in the office season
Off season
It beats watching TV!! :)
Struggling with "rotation" - my brain doesn't believe me when I tell it something unless I can explain why. It would seem that releasing the brakes takes weight off the front and places it the only other place it has to go...to the rear. Correct? If so, how does that help increase yaw? Since the timing of the release seems critical is it because the car becomes unsettled and a tiny bit of traction comes off the rear as a result?
You’re absolutely right that releasing the brake unloads the front tires, and that usually reduces rotation. What I was saying was that I was delaying the release of the brakes - extending trail braking - and that’s why this increased rotation. Make sense?
The key is what’s happening with the tire. The time constant of braking is smaller (think “faster”) than the time constant of the bigger/heavier springs/dampers. So, when the “fast” brakes are released, the tires suddenly are asked to do less and give more to turning traction before the “slow” weight has transitioned to the rear... meanwhile (we’re talking split seconds) the front grips more and thus rotates the car. It’s like riding a wave with the brake pedal balancing the braking and turning grip.
This is not what I'm talking about. I'm talking about a long, slow release of the brakes to keep the front tires loaded, and the rear tires less loaded. That's what causes the rotation, not a fast release of the brakes. A fast release of the brakes usually results in understeer, not oversteer/rotation.
I’m not talking about fast release of the brakes, either. Sorry for the confusion.
To coin a phrase, "Aha!". So in those split seconds the front tire gains grip BEFORE the load transfer moves to the rear, thus increasing yaw and we get rotation.
Thinking further, the more rapidly I release the brakes at the right moment the greater the effect? A paradigm example would be to "snap" the brakes off and the car would spin like a top?
I think my brain is beginning the understand the "why" behind the relationship between brake release and rotation. Thank you times a million. Now to put it into action....a little at a time.
No, that's not it. Snapping your foot off the brakes unloads the front tires and will likely (but not always) induce understeer, not rotation. It's the SLOW release of the brakes that keeps the front tires loaded that causes the rotation. If you snap your foot off the brakes, the front unloads, load goes to the rear, and the rear gains grip - so less rotation. Snapping your foot off the brakes will not cause the car to spin like a top. It's most likely to cause the car to plough or push almost straight ahead, and not rotate.
it is possible to overload the front tires with too much trail braking, but that is definitely not what I'm talking about in this article. I'm talking about keeping load on the front tires with a long, slow release of the brakes - trail braking a lot - keeping load on the front tires and unloading the rear tires so the car rotates a lot.
Does that make sense?
Ross, thanks for taking the time on this. I've written and erased four different responses to your comment over the past half hour because all of them would ultimately shine a brighter light on my ignorance. Maybe it will be easier to discuss in person next week at my favorite track and then I can add a chapter on rotation to my upcoming book "Performance Driving for the Completely Stupid". :)
OK, so further down the rabbit hole. In my quest to understand the "why" I found Andre Marziali's "Physics of Racing" on YouTube. At 31:55 in his video he explains the forces at play during trail braking, and along with everything I (mostly) already knew he added in the effect of the front suspension unloading. Using sample calculations it shows that the springs increase force without respect to mass when unloading AND that the rear loses force at a disproportional rate because it was under less load to begin with. Perhaps this is what I've been missing when trying to understand why load transfer from front to rear helps rotation. More study is needed.
I've come to believe my efforts to understand the "why" of rotation are bass-akwards. It's not about what the release of brakes is doing, it's what you're NOT doing if releasing them earlier. You're NOT transferring load to the rear prematurely which would prevent rotation. Hence the importance of "timing and rate".
So many corners where the physics don’t seem to match reality. Entry, minimum & exit speeds have a balance beyond my abilities (so far). Thanks Ross.