zzyzx

Adam, great to see you on here! I actually thought you were already posting.


You should stay on this thread and not make a sub thread because so much of what has been talked about here relates to topics in your books.

zzyzx

You guys should all read Adam's books, which were published just this past year.


(Disclaimer: I don't know Adam, the author, and don't have any connection to him.)


I would say that his books are not going to help someone who is totally new to racing. (The Skip Barber book is excellent for people new to racing, and also for drivers with experience.) These books are aimed at people like us who have some racing experience and want to dig deeper into cornering theory. These books (it is a three-volume set) are not easy reading, but they are really fascinating in how they explain cornering theory using concepts of physics and what has learned from data analysis. I can't recommend them highly enough!

Matt Romanowski

You've definitely hit the target for your audience and books. It's nice to have the "next level" of driving book that goes beyond the basics. Hopefully people read them and then apply the skills.

zzyzx

Can anyone explain the physics involved in a tank slapper?
Also, how you would explain the Scandinavian flick using concepts of physics?
Why is it that if you are holding a barbell, you can move the barbell more easily in one direction if you first turn it the other way? I.e., you flick the barbell with your wrist to your right, and then while it is still moving, you flick it to the left?

Veloce Raptor

For lack of a more technical explanation, it essentially creates a pendulum effect that loosens up the rotating end of the vehicle (the back).

Manifold

This is something of an illusion. The barbell will tend to continue moving in the direction it's already moving (conservation of momentum). The perception that it's easier to make it change direction comes from the favorably 'cocked' orientation of your hand when you change the direction.

zzyzx

Yeah, I suppose that's true. Now that I think about it, by moving the barbel in one direction first, you are stretching ligaments and muscle fibers in your wrist, which then want to retract and will contribute to making it easier to move the barbel in the other direction.

The way I've always explained it to myself is that when, say, the back of the car is oversteering heavily and sliding to the right, the slip angles of the tires are way beyond the point where they can produce any cornering force. Once the back of the car stops sliding (reducing the yaw angle) due to the friction of sliding and because of countersteering, the slip angles will get back to where the tires will suddenly regain cornering force, and since the steering wheel may still be pointed to the right, the car will swing around in the other direction.

However, I think this is only a partial explanation of how tank slappers happen. There's something else contributing. I think the springs in the suspension contribute. I don't think a vehicle with no suspension, like a go kart, would be as likely to do tank slappers.

Manifold

Yes, on the barbell, do the experiment you described and compare starting with the barbell stationary vs moving in the opposite direction of the direction you want to move it. The latter requires noticeably more momentum change, energy, work, and force.

Here's more on the Scandinavian flick (not a **** movie):

https://en.wikipedia.org/wiki/Scandinavian_flick

T&T Racing

LapI have read all three books and have it has helped to understand racing at the fundamental level. My educational background is holding a BS and MS engineering degrees. I decided to drive a race car after I retired from earning a living and had been a crew chief for Warren Agor's Monza team running in the IMSA series from 1975 - 1977. I attended the Skip Barber race driving school, earned a SCCA license, attended several Bob Bondurant advanced race driving schools, and then drove Warren Agor's restored Monza at DE's and SVRA. That was from 2001 to 2007.
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Then, I took a hiatus from auto racing until 2013 when I purchased a Greg Fordahl prepared Porsche 944 from the original in Seattle. My age at the time of purchase was 73. My yearly track time is limited to a few DE's and SVRA. My progress learning to drive a momentum with limited track time was accelerated using procoaches, namely Peter Krause, Peter Argetsinger and Simon Kirkby. My lap times at Watkins Glen have plateaued to a 2:28. Last Fall, Peter Argetsinger was my coach and he drove the race car for an entire DE session. The session was videotaped using a GoPro camera and track data recorded with an AIM MXL, witt h extra sensors for brake pressure and throttle position.
Here is my approach to reverse engineer Peter's data to develop a plan to improve my lap times.

1. Review Peter's best lap time (the four segment times were also the best times for the session ) video at half speed. Determine for each corner the straight line braking zone, the down shift point, the release of the brake point, the throttle maintenance point, the Euler spiral amount (rate over time and or distance), the apex point with where the car is pointing, and full throttle point. My approach is to view the video to determine when he lifts his right leg to go from throttle to starting of braking (freeze the video and save the image), and so on for all key points to track out.
2. For the track data, I divided the track into 4 segments. The track data displayed on the split screen was brake pressure, throttle position, lateral acceleration, and the math channel Radius.
3. For each segment, I zoom in to expand the x axis, distance, to index the track data with the instantaneous frozen track video image.
4. This cumulative data a video is the inputs to my lap time improvement plan.

It is labor intensive, but it is a good winter project. Maybe a refurbished AIM Smartycam will come my way. Any offers, free for a trial or BO?

I completed the analysis from throttle lift to start of turn in for corner 1

Keep you posted on what I learn


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Gary R.

Why have Adam's posts been deleted??

Manifold

Adam Brouillard just put out this excellent video which illustrates some of the concepts in his books:


I've spent a lot of time reading and re-reading Adam's books, and have found that his insights and guidance are validated by careful study of videos and data from top drivers. I don't know of any resource which presents what Adam is presenting with as much clarity and depth as Adam - and so far, he's giving away these pearls of wisdom pretty much for free!

Gary R.

Thanks for re-posting the video!

DTMiller

Sponsor rules, I'd bet. Sometimes we lose value around here as a result but rules are rules, I guess.

Manifold

I wasn't aware of any deleted posts, but am happy to spread the word about Adam's excellent work. Adam has improved my approach to driving and instructing more than perhaps any other resource.

I've watched the Skip Barber video many times, but IMO this video from Adam goes well beyond it.

ProCoach

It's practical information you can USE...