Sawing at the wheel
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From: Edmond, OK
Sawing at the wheel
Why do some top drivers seem to saw a lot at the wheel when they are driving and others seem to be very smooth with their hands? What does sawing accomplish and when is it appropriate?
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From: ..............
seeking and testing for front end grip near limit --
read this ... u will be sorry u asked hahaha
https://rennlist.com/forums/racing-a...le-work-2.html
read this ... u will be sorry u asked hahaha
https://rennlist.com/forums/racing-a...le-work-2.html
Drifting
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From: TX
I asked this question to instructors early in my development and could not get a really firm answer other than "searching for grip". My own explanation for this is thinking about how one would describe how they ride a bicycle. It is very hard to put into words, yet lots of people do it all the time. As time progressed, a funny thing happened, upon reviewing my own videos, I started doing it. Now, I don't do it a lot, but in my hottest laps, I do it. I almost never remember doing it in real time.
I'll just leave this here. If I hadn't have been looking at him, never would have "felt" the sawing for all but the "calibration" moves:
-Mike
I'll just leave this here. If I hadn't have been looking at him, never would have "felt" the sawing for all but the "calibration" moves:
-Mike
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It's unusual, not very common and not supported by data, but if it salves the drivers confidence, so be it.
That said, I went through a phase where I thought I needed to do that to "feel" grip, about twenty-five years ago. When I began in professional motorsports and Skip Barber, I learned that this was a subjectively required technique, not an objectively derived one.
When I see that on video with folks I am working with, most aren't aware they are doing this.
John Block has a great x-y plot in data called "steering panic," which tracks speed and amount of times steering angle changes without forces acting on the car changing much, if at all. Great chart!
That said, I went through a phase where I thought I needed to do that to "feel" grip, about twenty-five years ago. When I began in professional motorsports and Skip Barber, I learned that this was a subjectively required technique, not an objectively derived one.
When I see that on video with folks I am working with, most aren't aware they are doing this.
John Block has a great x-y plot in data called "steering panic," which tracks speed and amount of times steering angle changes without forces acting on the car changing much, if at all. Great chart!
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Every fast/pro driver straddles the peak of the grip vs slip-angle curve. Depending on the shape of the grip curve (sharp/narrow for a hooked up race car on slicks, wider for a street car on rcomps or street tires) and the ability of the driver to keep the straddle tight around the peak (not venture too far below or beyond it) the corrections will be more visible to an outside observer or less.
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Every fast/pro driver straddles the peak of the grip vs slip-angle curve. Depending on the shape of the grip curve (sharp/narrow for a hooked up race car on slicks, wider for a street car on rcomps or street tires) and the ability of the driver to keep the straddle tight around the peak (not venture too far below or beyond it) the corrections will be more visible to an outside observer or less.
Like many high level drivers (and this is the difference between the Am and the top-level Pro), Schuey is SO well tuned in his butt gyro that he will pitch the car in OVER the limit, in such a way that the car is doing a series of little "slides" as he adjusts the heading of the car to the most desired yaw rate for the radius he desires.
Your strip chart only shows his inputs, not the response (or stimulus to him) of the car. This is why you MUST have the whole picture (or at least more measuring points) before coming to a conclusion. THIS is why video is such a powerful tool!
It has been my experience that nearly all DE folks and most club level drivers that display "sawing" of the wheel are not generating the slip levels or yaw on a CONSISTENT or SUSTAINED basis to justify the amount and frequency of steering input they use. Usually it's a "save your butt" correction, not a planned, executed and continuous thing...
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Drifting
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I drive a fwd car w/ low hp in DEs/open track/lapping days so in order to keep my foot in it I do find myself sawing to scrub off speed at times.....I have no data to show if it's faster than other alternatives (other than noting my exit speeds out of the corner) but it gets me through the turn, and since I'm not (consciously) lifting it "feels" faster (so it probably isn't 
).
I do find myself consciously doing it more on a wet track to feel for grip/lack of.
Gary
).I do find myself consciously doing it more on a wet track to feel for grip/lack of.
Gary
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From: Edmond, OK
Originally Posted by golfnutintib
Originally Posted by ProCoach
I learned that this was a subjectively required technique, not an objectively derived one.
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2) Smooth has 2 reference points. Inside the vehicle and external to the vehicle. You don't have to have "smooth" hands inside the vehicle to have a "smooth" vehicle at the contact patch. To the contrary,
3) If you always have smooth hands, you are definitely not driving at/near the limit.
4) That is "sawing" in a corner can help certain drivers in certain platforms maximize grip. You will see a LOT of video of top drivers doing this.
Although I don't have any actual impircal data and have never studied it specifically, the anecdotal evidence and I've seen seems to back this up. I'm sure someone out there has data to provide a better analysis.
In my very limited and less than stellar experience, the faster the corner, the less I might correct in it. I suppose that's just self preservation!
-td
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What's not being shown in the video is the constant feathering of the accelerator. Everytime you press on that thing in a RWD you are creating grip, but you don't want too much grip in the rear or you oversteer too much.
At any given time, your car has a defined amount of grip. This means your car can maintain a specific, pre-determined maximum velocity on any given corner, assuming you're on the record line. Physics dictates your car will necessarily slow down during the turn, so you need to feather your accelerator to maintain this pre-determined maximum velocity. As you feather, you are teetering from slight below to slightly above this velocity curve. Hence, you ABSOLUTELY MUST have steering inputs to counter the oversteering your are generating through your feathering.
I hate to say it, but high performance racing is in many ways similar to drifting. Which is why most of the elite racers in Formula 1 and LMP1 are excellent rally and can outdrift and do donuts around most people. Straddling the edges of grip and controlling what is in essence a constant state of oversteer is something any quality driver should be able to do. When your tires screech, that means you are at the edges of grip.
1:20 for a good example. Watch the RPMs and throttle meter carefully to see the variations in 3rd gear during the turn and the corresponding and resulting necessary countersteering action.
At any given time, your car has a defined amount of grip. This means your car can maintain a specific, pre-determined maximum velocity on any given corner, assuming you're on the record line. Physics dictates your car will necessarily slow down during the turn, so you need to feather your accelerator to maintain this pre-determined maximum velocity. As you feather, you are teetering from slight below to slightly above this velocity curve. Hence, you ABSOLUTELY MUST have steering inputs to counter the oversteering your are generating through your feathering.
I hate to say it, but high performance racing is in many ways similar to drifting. Which is why most of the elite racers in Formula 1 and LMP1 are excellent rally and can outdrift and do donuts around most people. Straddling the edges of grip and controlling what is in essence a constant state of oversteer is something any quality driver should be able to do. When your tires screech, that means you are at the edges of grip.
1:20 for a good example. Watch the RPMs and throttle meter carefully to see the variations in 3rd gear during the turn and the corresponding and resulting necessary countersteering action.
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Looks like a mistake to me.
Barlesi is not an example I would use to justify this technique, or to even illustrate the very fine balance of grip and slip. His website is dead and other than some regional karting championship and the local FLM series championship in 2010, he didn't ever get anywhere. Interesting his team principal from this video, Vitafone's 2009 FIA GT1 World Champion Michael Bartels, is here at Daytona racing this weekend. Now, he's fun to watch! And smoooth...
Barlesi is not an example I would use to justify this technique, or to even illustrate the very fine balance of grip and slip. His website is dead and other than some regional karting championship and the local FLM series championship in 2010, he didn't ever get anywhere. Interesting his team principal from this video, Vitafone's 2009 FIA GT1 World Champion Michael Bartels, is here at Daytona racing this weekend. Now, he's fun to watch! And smoooth...
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This was him when he was 20 years old. Imagine being given an LMP2 car at 20. One thing I really like about him is he shares his data online. You can see what gear he's in, his throttle and braking.
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Interesting that you should post an LMPC (Oreca FLM09) video. I happen to be working with a team this weekend at Daytona running one of several. Butch Leitzinger is co-driving with the owner.
It is my professional opinion that Barlesi is still driving prototypes and GT cars like a kart. He's never been able to break that habit, based on both of the videos you've posted. There is no question his steering inputs are exaggerated and many (including the provocations and resulting corrections) are unnecessary.
This type of technique is not desirable and is not helpful to the engineers working on the team because it is not possible for the driver to evaluate any sort of steady-state handling or balance states. The engineers would have to spend an inordinate amount of time diagnosing if the car was doing that to him, or he was doing that to the car! Haha!
I've worked with a pro driver (who people on this forum have worked with) who made it nearly impossible to engineer the car due to the inconsistency and sheer amount of "steering panic" he inflicted on the car. Was he fast? Sure. He "hustled" the car, and that can count for a lot. At least until the tires degrade more rapidly and the platform goes away.
I prefer the Colin Braun school of steering input. One of the most versatile and accomplished pro drivers, he is a joy to engineer and takes very, very good care of the equipment. He's even faster than the above mentioned pro...
This is Colin in the car he won the IMSA LMP-C title in 2015. Same car as above video.
It is my professional opinion that Barlesi is still driving prototypes and GT cars like a kart. He's never been able to break that habit, based on both of the videos you've posted. There is no question his steering inputs are exaggerated and many (including the provocations and resulting corrections) are unnecessary.
This type of technique is not desirable and is not helpful to the engineers working on the team because it is not possible for the driver to evaluate any sort of steady-state handling or balance states. The engineers would have to spend an inordinate amount of time diagnosing if the car was doing that to him, or he was doing that to the car! Haha!
I've worked with a pro driver (who people on this forum have worked with) who made it nearly impossible to engineer the car due to the inconsistency and sheer amount of "steering panic" he inflicted on the car. Was he fast? Sure. He "hustled" the car, and that can count for a lot. At least until the tires degrade more rapidly and the platform goes away.
I prefer the Colin Braun school of steering input. One of the most versatile and accomplished pro drivers, he is a joy to engineer and takes very, very good care of the equipment. He's even faster than the above mentioned pro...
This is Colin in the car he won the IMSA LMP-C title in 2015. Same car as above video.
