Spinning at Buttonwillow (1CW)

[orthojoe]

Skip to 17:57
This is what you did:
[ame="https://www.youtube.com/watch?v=RAZV_o3b7NU"]Ana BRZ Laguna Seca Session 2 - YouTube[/ame]



Start at 3:48 and ignore the ridiculous fanfare. Watch my steering wheel position
Go to 5:38, and you can watch from behind.
This is what you should do:
[ame="http://youtu.be/QsEVH4z8Eec"]http://youtu.be/QsEVH4z8Eec?t=3m48s[/ame]

[ddeflyer]

Originally Posted by orthojoe

OP, this looks like a pretty straight forward situation to me. This has nothing to do with VSC.

It has everything to do with you still having steering lock applied when you dropped 2 off and immediately came back on track. You hooked the car. This is almost impossible to save. Think about it this way: When you drop 2 off and your steering wheel is still turned in a direction that will take you back on track, the FRONT tires gets back on pavement first and regains traction. However, the rear still doesn't have traction while it's on dirt. Then the rear suddenly gains traction as it comes back onto the pavement, and you still have steering lock. What happens then is major oversteer. The vast majority of cars have been lost on the race track in this fashion. Turn 3 and 4 at Laguna Seca. Turn 15 at Thunderhill.

What you should have done:
a) Realized that you were going too fast through that turn and that you weren't going to make it
b) drive straight off the track. Not just off. Straight off.
c) allow the car to settle and slow down off the track
d) slowly and gently bring the car back onto the track in a fashion where you are gliding back onto to the track with your steering wheel pointed straight forward as you get back on.

All this other talk about countersteer, adding throttle, reacting faster, etc, etc means nothing. As soon as you dropped 2 off, that all went out the window.

BTW, this wasn't a tank slapper. A tank slapper involves the rear end rotating from one direction to another. You only rotated in one direction: counter clockwise.

Glad to see that all you needed was a vacuum cleaner to get back into play.

There are alot of things I am still unsure about with all of this, but one that I am completely certain of is that the rear end of the car was yawing (relative to the front end) back and forth. It was not a major tank slapper and is barely visible in the video (frankly it is barely visible in the full res video even), but it did happen. I don't know if that had anything to do with the actual off or if it just distracted me so I didn't see how close I was to the berm, but it was there. If I had seen/felt I was going off I would have gone straight (which may be due to the distraction of the tail wagging) which I've done before (dropping two wheels and also on the other time I've gone four wheels off). Once I felt the tail pop I tried to go straight but it was too late.

As far as the actual dropping wheels off, even though it looks kind of like it from the video, I am not sure my front right wheel actually went off the berm. The rear right did for sure though. Tonight I am going to setup the gopro again and get some frame grabs to see where things line up from that perspective.

Honestly I managed to get myself into a situation that overwhelmed both my safety buffer (consumed by exiting the turn faster than I had ever exited it before and maybe some effect of the tail wagging making me track further out) and my ability to handle emergency situations (because there was a minor strange thing happening to the tail of the car that took my focus). Part of the learning experience is to understand what happened and my gut is telling me that this might not be the classic two wheels dropped scenario.

[orthojoe]

Originally Posted by ddeflyer

As far as the actual dropping wheels off, even though it looks kind of like it from the video, I am not sure my front right wheel actually went off the berm. The rear right did for sure though.

That is all you need for what happened to occur.

[ddeflyer]

Originally Posted by orthojoe

That is all you need for what happened to occur.

And that is where things are really fascinating there. What I remember feeling was that the tail went right, then VSC pulled it left and then it started going right again (which I think might have been part of the VSC catching the leftward movement) at which point it just went the whole way around. You can see some of this I think if you watch the video very closely as the suspension unloads from the left hand side for two or three frames before starting to go around.

Irrespective of if the VSC over corrected and pushed the rear wheel out or if it was just natural oversteer, I have a major fault here in that I should have triggered my go straight recovery plan as I came to the berm with oversteer happening. Unfortunately I am not as experienced dealing with oversteer (and where the car is while oversteering) as I am with other non-optimal handling scenarios. Before this double day I had been using stock alignment and mostly all VSC on full so situations like this would have been nose first. Tail being the outside point (relative to the tarmac) is not something I have much experience with yet.

On a totally unrelated note, do you go with HOD very often? I've been to several with them so I'm wondering if I've seen you there.

[orthojoe]

Originally Posted by ddeflyer

And that is where things are really fascinating there. What I remember feeling was that the tail went right, then VSC pulled it left and then it started going right again (which I think might have been part of the VSC catching the leftward movement) at which point it just went the whole way around. You can see some of this I think if you watch the video very closely as the suspension unloads from the left hand side for two or three frames before starting to go around.

Did you feel this happening after you dropped a wheel off? If so, yes, VSC was trying to save you. However, as I said before, this type of situation is almost impossible to save, even with stability control.

On a totally unrelated note, do you go with HOD very often? I've been to several with them so I'm wondering if I've seen you there.

Yes, I frequent HOD events. You have probably seen me there.

BTW, this is a real tank slapper (start at 0:53)
[ame="https://www.youtube.com/watch?v=k37BQvcKk6c"]Laguna Seca Near Disaster July 2012 - YouTube[/ame]

[ddeflyer]

Originally Posted by orthojoe

Did you feel this happening after you dropped a wheel off? If so, yes, VSC was trying to save you. However, as I said before, this type of situation is almost impossible to save, even with stability control.

Yes, I frequent HOD events. You have probably seen me there.

BTW, this is a real tank slapper (start at 0:53)

Yeah, maybe I shouldn't be calling it a tank slapper since that implies a much stronger and longer duration back and forth.

What I am referring to started well before I was to the berm. Specifically, a little after I passed the apex I added some steering input (I think I was trying to get myself back into the seat better and basically bumped the wheel as I tried to lever back into the seat) to the left. This brought the rear end out a little and the VSC activated. At this point it brought the rear back relative to the direction of travel or even slightly to the left. At this point I am just a foot or two from the berm, and either the tires just caught hold and pushed it back right or the VSC tried to damp the oscillation and started it going right again. Either way, the end result was that the rear stepped out that half foot or so needed to get off the berm and start the spin. All I knew at the time was that instead of a damping oscillation it just kept going. I went to straight but it was too little too late. I didn't even realize at the time that any tires had dropped until I saw the video.

[ddeflyer]

Another detail about the day in general is that I was trying to explore the sensations of oversteer and traction sensing on the tail of the car by getting some slight oversteer going and letting the VSC catch it (well, really I was trying to get some oversteer without the VSC activating but I'm not that good at balancing the car yet). I was primarily doing this on Bus stop but I think I let some of that creep into other turns such as this one. My goal was to get familiar with the sensation before totally disabling VSC so I would have a better set of reactions when the tail started to come out. Obviously it didn't work out so well...

[orthojoe]

Originally Posted by ddeflyer

Yeah, maybe I shouldn't be calling it a tank slapper since that implies a much stronger and longer duration back and forth.

What I am referring to started well before I was to the berm. Specifically, a little after I passed the apex I added some steering input (I think I was trying to get myself back into the seat better and basically bumped the wheel as I tried to lever back into the seat) to the left. This brought the rear end out a little and the VSC activated. At this point it brought the rear back relative to the direction of travel or even slightly to the left. At this point I am just a foot or two from the berm, and either the tires just caught hold and pushed it back right or the VSC tried to damp the oscillation and started it going right again. Either way, the end result was that the rear stepped out that half foot or so needed to get off the berm and start the spin. All I knew at the time was that instead of a damping oscillation it just kept going. I went to straight but it was too little too late. I didn't even realize at the time that any tires had dropped until I saw the video.

Bottom line is, you were going too fast through that corner. The error was not realizing that soon enough. VSC on/off is irrelevant. If it was off, you would have spun as well and most likely sooner because you added steering input after going past the apex. You had to add steering input because the line you were driving was going to take you off course. Adding that steering input pushed the car into oversteer, your VSC probably stopped you from spinning out before you dropped a wheel. Once you dropped the wheel off, it was beyound what VSC could save.

[orthojoe]

Originally Posted by ddeflyer

Another detail about the day in general is that I was trying to explore the sensations of oversteer and traction sensing on the tail of the car by getting some slight oversteer going and letting the VSC catch it (well, really I was trying to get some oversteer without the VSC activating but I'm not that good at balancing the car yet). I was primarily doing this on Bus stop but I think I let some of that creep into other turns such as this one. My goal was to get familiar with the sensation before totally disabling VSC so I would have a better set of reactions when the tail started to come out. Obviously it didn't work out so well...

VSC doesn't allow much slip angle at all. Bouncing off VSC isn't the best way to do this. Skid pad is the best way to practice this, IMO. I rented out the skid pad at thill recently, and this really helped me a lot.

[ame="https://www.youtube.com/watch?v=6PxFUqr9u3Y"]Skid pad practice at Thunderhill - YouTube[/ame]

[CSG Mike]

Originally Posted by ddeflyer

Yeah, maybe I shouldn't be calling it a tank slapper since that implies a much stronger and longer duration back and forth.

What I am referring to started well before I was to the berm. Specifically, a little after I passed the apex I added some steering input (I think I was trying to get myself back into the seat better and basically bumped the wheel as I tried to lever back into the seat) to the left. This brought the rear end out a little and the VSC activated. At this point it brought the rear back relative to the direction of travel or even slightly to the left. At this point I am just a foot or two from the berm, and either the tires just caught hold and pushed it back right or the VSC tried to damp the oscillation and started it going right again. Either way, the end result was that the rear stepped out that half foot or so needed to get off the berm and start the spin. All I knew at the time was that instead of a damping oscillation it just kept going. I went to straight but it was too little too late. I didn't even realize at the time that any tires had dropped until I saw the video.

What you experienced was slip angle. Maintaining slip angle is the fastest state of cornering.

It's what people are referring to when they say that they feel like the car is "floating" when I drive, and that my steering inputs seem to have no correlation with what the car is doing.

At a basic level, your steering inputs shift the direction of the front of the car. At a more advanced level, your driving inputs shift the thrust angle of the car.

[CSG Mike]

Originally Posted by orthojoe

Bottom line is, you were going too fast through that corner. The error was not realizing that soon enough. VSC on/off is irrelevant. If it was off, you would have spun as well and most likely sooner because you added steering input after going past the apex. You had to add steering input because the line you were driving was going to take you off course. Adding that steering input pushed the car into oversteer, your VSC probably stopped you from spinning out before you dropped a wheel. Once you dropped the wheel off, it was beyound what VSC could save.

I don't think he was going too fast through the corner. VSC was not stopping the slip angle (it allows some slip).

What did happen, IMO, is that he got nervous as a result of the slip angle, and eased up on turning compared to what he would normally do, which ultimately resulted in a 2 off. The increased velocity doesn't help.

[ddeflyer]

There were two other issues that happened there; one was that I hit a bit of an early apex and the second is that I was pretty far out from the apex. The first was just a simple mistake, the second is an artifact of my originally being scared of the track out with the nasty inside berm being tall (so fear of hitting it and having the tires come off the ground and killing traction).

[ddeflyer]

Originally Posted by CSG Mike

What you experienced was slip angle. Maintaining slip angle is the fastest state of cornering.

It's what people are referring to when they say that they feel like the car is "floating" when I drive, and that my steering inputs seem to have no correlation with what the car is doing.

At a basic level, your steering inputs shift the direction of the front of the car. At a more advanced level, your driving inputs shift the thrust angle of the car.

I've only had a few experiences with balanced, steady state slip angles and it is one of the pieces that I am trying to put together.

Earlier in the day I managed to get just the right balance of smooth entry, throttle and initial speed to get VSC to allow substantial slip angle through the bus stop. It was an amazing feeling as I released some of the steering lock (what felt to me like a slight counter steer though the wheel was still turned into the turn) and just kind of gained speed as the car turned so nicely! I want to get better at the pre-conditions for that so I can confidently disable the VSC and know how the car will behave.

I'd had it the weekend before once at T-Hill also. Going around turn 6 when I got just the right throttle at turn in. That time I was scared and didn't hold it there but it was such an amazing sensation. Prior to that I'd only had some brief moments of slight rear slip angle when I got my tires greasy going over 5, so it just felt crazy and scary to have the car move underneath me like that.

[mike the snake]

I'm glad you were almost fully turned around by the time you went into the dirt. I've seen cars hit the dirt sideways and dig in with really bad endings.