Lessons to learn from track cam footage? (errors spins crashes )

[flipper35]

Originally Posted by LeeH

Shocktek's Michael G. O'Callaghan further explains the problems encountered by most street cars: "Typically, when the shocks are at the end of their life cycle, the rod seal will fail (hopefully slowly) and the shock absorber fluid will leak out. The damping characteristics of these aged shocks are not good: the overall damping forces are much lower, the damping curves have changed and there may be air in the shock which may act like a spring. Bottom line: wheel hop, uncontrolled porpoising, excessive body roll. Very dangerous in a collision avoidance maneuver. [Source]

Another guy (I can't remember his name at the moment) on the same note that does a lot of Miatas and S2000s on a shock dyno said they will hit the bump stops as well and it throws off the wheel rates pretty badly.

[winders]

Originally Posted by john rogers

....never brake when turning (although this can be modified now with the new cars and ABS)

Sigh.....this is just wrong. You don't need ABS to trail brake and, if you want to be fast, you better figure out how to trail brake!

P.S. When I road raced motorcycles, I did a lot of trail braking too.

[Geneman]

Thanks for chiming in Scott.. while still I consider myself a newby,... have had most coaches and other peeps tell me .. exactly that what you said.... you must accomplish weight transfer ( even with the rear engine oversteer tendency of a 911) during cornering ...reduces understeer on applying throttle at near apex... .
i have had to painfully unlearn most of DE habits to race... possible most importantly expunge from your muscle memory is straight line braking... whilst a great teaching ( and safety tool for both instructors and students)..not good for racing... and the abs comment is spot.. chhers frank

[aigel]

Originally Posted by LeeH

Autocrossing in a parking lot is probably about as safe as it's going to get... assuming you choose a parking lot without trees.

And THAT is why you keep your arm inside the window when instructing / being a passenger in an event ... I wonder if the guy was able to pull the arm in in time.

G

[Geneman]

Tim T in that Lime Rock Lap video you posted seems like the driver is leaving alot of time on the table.. he is way late to throttle vis a vis apex at most turns.. (maybe not comin out of big bend) but the rest ... ... would be great to have some telemetry... moreover he is modulating throttle throughout most of big bend.. .. the aces told me to treat big bend like turn 17 at sebring drive deep into it before braking, then rotate the car, drop a gear and accelerate out with the ass end doing its job... ( but actually while typing this i realize he is not in a rear engine car which could account for it..)

[sugarwood]

TimT, you're blowing away cars on the straights. What car is in the 4 videos?
The car sounds like a jet plane. Is that the sound of a Turbo?

[TimT]

Tim T in that Lime Rock Lap video you posted seems like the driver is leaving alot of time on the table..

That video was of of first lap out of a car that had been completely rebuilt from the ground up... its maiden voyage.... Yet even holding back driving at 6-7/10th did a 1:00 lap at LRP which is nothing to sneeze about....

It was as DE, did you see how fast the car closed on the "pack"?

but actually while typing this i realize he is not in a rear engine car which could account for it..

Really? don't recognize that big Tach in the center of the dash? The car is a 935 copy.. built on a 79 930 tub...

The car sounds like a jet plane. Is that the sound of a Turbo?

You are hearing the sounds that a high strung 800 hp turbocharged flat six makes....

Waste gate, blow off valves, turbo...

[sugarwood]

VIDEO #3
What went wrong in this turn?

[VaSteve]

Looks like fixated on the car in front (or the one behind). Looks like a little early turn in combined with hitting the curbing and likely panic lifted. You can't really tell since its a bumper cam and not from inside the car.

SUgarwood with all due respect if you're this concerned about track spins and such, track driving is probably Not for you

[Christien]

Interesting to note that 2 of the 4 crash/spin videos have the driver losing control and regaining it before the loss of control that led to the crash. If you get slippery and recover, the best thing to do (imo) is to hit the bits and debrief. Clear your head, reflect on what went wrong, then head back out and don't do it again. These goofs are far too manly to let a little loss of control get in their way, and look what happened. In my experience, the majority of crashes are caused by people driving beyond their own skill level, usually due to ego. Keep that in check and you'll be fine.

The last one seemed much smoother, like the driver knew what he was doing and just overcooked it a bit, which happens. But look at some details: first, he did it in a place with lots of runoff room, and second, he pulled off the track, presumably to catch his breath and make sure everything looks clear before completing the lap. That indicates someone who knows what they're doing.

[sugarwood]

I watched video #1 again, and saw that his hands were pretty slow in the countersteer.
He needed to have faster hands violently turning that wheel left, right?

[Z-man]

Originally Posted by sugarwood

What does "tracking out" mean?

I watched #1 again.
Is turning a bit too early such a huge error that you end up crashing?

This video kind of concerns me.
#1 did not suddenly jerk the wheel or do anything reckless.
Once he was in oversteer, he corrected his steering.
Meanwhile, he totaled his car and could have gotten hurt or killed.
I was under the impression AX and DE are somewhat safe, but I am rethinking that.

There are some things worth noting in the Subaru crash at Lime Rock that are not revealed in the video:

1. The Red mist. The Subbie driver was attempting to catch up to and pass Howard, who was driving the 911. (I wasn't at the track when the crash occurred, but I am friends with Howard). So the driver was overdriving. I have seen this all too often at track events. There is no need to have that mentality at a DE - you are there to learn how to drive, not to compare your speed and ability with other drivers and cars. Your trophy is the ability to take your car home in one piece - drive with that in mind. The Subaru driver did not have this mentality.

2. The video seems to indicate that the driver is an early-apexer: he early apexed the entry onto Noname straight (the back straight at Lime Rock - before the uphill turn where he went sunny side down). While early apexing a corner is sometimes the best line through a corner, that is not the case with the Uphill turn at Lime Rock.

3. The Uphill can be a tricky corner: right after the turn-in, the angle of the track becomes very steep, which compresses the suspension and with it comes a lot of grip. However, the hill levels off a bit just before the turn straightens out. At that point, the suspension gets uncompressed for a moment, and then settles down. If during that part of the turn the wheels are not pointed straight, the car can get a bit squiggly. If the driver over-reacts to that squiggle, the car will wind up in the tire wall to the right of the track. But the Subaru driver met his fate long before the track-out point.

4. As I mention in the point above, the uphill is quite steep. The driver was out-of sorts as he entered the turn, and his car was sideways to the track just about where the track was the steepest. you can't really see how steep it is in the video. At that point, physics took over: the driver's side suspension compressed against the track, and his momentum essentially caused his passenger side to lift up and soon thereafter, his roof met up with the track!

While Lime Rock Park is not a complicated track - it is a very technical track. Get one turn wrong, and you pay for it for the rest of the lap. Of all the tracks I have driven on in the Northeast, Lime Rock is by far my favorite track: every time I have gone there, I have learned a difference nuance of the track.

Do not be discouraged by that video - if you keep your head about you, and drive to your ability, Lime Rock can be a very rewarding and safe place to hone your track experience.

Originally Posted by sugarwood

I watched video #1 again, and saw that his hands were pretty slow in the countersteer.
He needed to have faster hands violently turning that wheel left, right?

Actually, no. Violent, jerky motions are NOT proper techniques for track driving, even in that video. The driver should have reacted earlier and made a correction sooner, but with a smooth, deliberate motions. The difference between an amateur driver and a pro driver is not how fast he moves his hands, but how soon he realizes a correction is necessary. The sooner a driver can make a smooth correction, the faster he will go. This is known as driving 'infront' of the car or ahead of the car. Amateur drivers typically only react when something gets out a sorts, but pro drivers act (make corrections) before they need to react to their car being out of sorts.


-Z-man.

[sugarwood]

Thanks for the analysis.

Originally Posted by Z-man

Actually, no. Violent, jerky motions are NOT proper techniques for track driving, even in that video. The driver should have reacted earlier and made a correction sooner, but with a smooth, deliberate motions. The difference between an amateur driver and a pro driver is not how fast he moves his hands, but how soon he realizes a correction is necessary. The sooner a driver can make a smooth correction, the faster he will go. This is known as driving 'infront' of the car or ahead of the car. Amateur drivers typically only react when something gets out a sorts, but pro drivers act (make corrections) before they need to react to their car being out of sorts.
-Z-man.

That said, if an advanced driver was magically placed into that exact spot in time,
he would have countersteered harder and faster than the Subie guy did, right?
Look at his hands, he barely countersteered!

[Z-man]

Originally Posted by sugarwood

Thanks for the analysis.

That said, if an advanced driver was magically placed into that exact spot in time,
he would have countersteered harder and faster than the Subie guy did, right?
Look at his hands, he barely countersteered!

There are many different ways that accident could have been avoided. Most effective would have been to countersteer significantly sooner that the driver did - A veteran driver would have realized he was coming in too hot too early, and would have adjusted right after turn-in. He would have known that the steepness of the track would give him more grip right after turn in, where he could make more adjustments to ensure he won't fly off the track after track-out.

Another technique that may have helped save the car would have been to put the car into a full spin. There's a 1 in a million chance that could work, but if the driver would have gotten the car around 180 degrees before the hill, and gone up the hill backwards, it would have prevented the car from flipping. Those types of 'saves' are more lucky than anything...

-Z

[winders]

I am going to disagree again.....

What appears to be happening from outside the car and what is happening inside the car can be very different. A well driven well setup car at or slightly beyond the limit will look smooth, deliberate, and under control from the outside. But, what is happening with the steering wheel may look completely different. Corrections at the limit are done quickly with anticipation. They will not look smooth or deliberate.

See here:

https://www.youtube.com/watch?v=EokoS6R_6c8

Now, if you are driving at a DE at 7/10's, sure, everything should look smooth and deliberate and there should be no real corrections required.

[Tervuren]

Originally Posted by winders

I am going to disagree again.....

What appears to be happening from outside the car and what is happening inside the car can be very different. A well driven well setup car at or slightly beyond the limit will look smooth, deliberate, and under control from the outside. But, what is happening with the steering wheel may look completely different. Corrections at the limit are done quickly with anticipation. They will not look smooth or deliberate.

See here:

https://www.youtube.com/watch?v=EokoS6R_6c8

Now, if you are driving at a DE at 7/10's, sure, everything should look smooth and deliberate and there should be no real corrections required.

I used to think smooth meant slow deliberate motions until I actually started racing.

I've since redefined smoothness, as being able to hold the car to the limits without exceeding those limits. Smoothness is the ability to hold the vehichle at 100% without going to 100.01%. If you take a graph of available grip, a smooth driver maintains it closer to the line without excessive overs or dips.

On a track surface that has video game quality smoothness, no wind, and no other race car around to mess with your aero, your amount of input changes will be mostly limited to setting the car, then moving to a fairly constant corner rate, then transitioning to tracking out on and picking up speed on exit.

Throw in a bump in the road, or a patch of smooth concrete going to deeply etched asphalt, and you need to make extremely rapid inputs as your front wheels find grip that your back wheels won't have, followed by grip your back wheels have but your front doesn't.

The other side, is balance, this is shifting around where you have your grip as you set the car differently.

There is a distinction between making rapid steering input changes as late corrections, vs rapid steering input changes to hold a car at the limit. If you do not allow yourself the second, you will limit your abilities. If you are doing the former, back the frick down and chill until you get a feel for whats going wrong.

[Tervuren]

Originally Posted by winders

Sigh.....this is just wrong. You don't need ABS to trail brake and, if you want to be fast, you better figure out how to trail brake!

P.S. When I road raced motorcycles, I did a lot of trail braking too.

Notice how he said don't try to follow the guys who know what they are doing? Those guys aren't following that advice. This is good advice though to keep someone relatively safe. In a motorcycle or kart, braking and cornering once set/leaned over will absolutely kill your speed brutally, as you have to feed in a lot of steering input to overcome the braking force on the outside of the center of gravity. Ideally, you want to be on throttle in the corner enough to not have engine braking, so that this force outside the center of gravity is helping you corner from your back tire, letting you straighten the front wheel.

Corners you want to slow the frick down, and are not trying to carry speed or get a good exit, you can brake and turn, but you will be putting a lot of heat into your tires. Not recommended for street tires on a track, as you'll get a lot of fade out fast doing that.

A corner with high entry speed, and a slow corner right after, requires braking in the corner, and its an act of balancing grip levels to the different actions. A leaned over motorcycle is going to push like mad with either front or rear braking(assuming you don't exceed the rear tire's grip and snap oversteer).

I would not say the advice was "bad", but that it was a safe over generalization.

[Z-man]

winders, tervuren - smooth, deliberate, and quick are relative terms, I suppose. Winders: you say what is outside the car, and inside the car are two very different looking things -- and I agree. But if you take it a step further - inside the driver's mind - that is where the smoothness is most evident - especially if the driver has the ability to anticipate well ahead of the need for an input. I should not have said deliberate - perhaps calculated and efficient (and quick) are better ways to describe the techniques... You don't see veteran drivers flailing and sawing at the steering wheel for no reason, do you?

The video in the OP's first post was at a DE event, not a race. At DE's, one should not focus on racecraft, but rather on techniques associated with performance driving. Granted, at times those two overlap. I have not dived into club racing (yet). So my experience is indeed limited to DE's and autocross.

Now if that bozo parking in the fast lane would just MOVE OVER...

-Z

[wayner]

Here is a lesson that I have hopefully learned from watching a video before it happens to me!

As 911 owners we've all hopefully been schooled about lift throttle oversteer and how our cars will leave the road backwards if we are not careful.

I've always been very deliberate in my actions and being careful not to do that ENTERING a corner. BUT, I never considered that the situation may be created when entering on to a straight until this video was posted. Now it seems so obvious to me that this can happen.

The first video shows a guy getting it wrong (pinch the corner exit and lift at 1:19- oops, and yes I know that a slide started entering part II, of the corner but it all went wrong when he ran out of track and pinched at the exit.)

The second video shows a pro's better reaction to running out of room (stay in it and put a wheel off at 2:20 in the second video)

I'm all ears though to learn more form the pros.

See 1:19 in video one and 2:20 in video 2)

[sugarwood]

Originally Posted by Z-man

Most effective would have been to countersteer significantly sooner that the driver did
-Z

You're right, in VIDEO 1 he's very late in beginning to correct.
It's like he's missing that instinct you develop as a teenager doing fishtails in the snow.


You think he flipped because of the incline?
I assumed he was just to fast sideways, and he caught traction on the dirt or grass.
Are you saying it's pretty hard to flip your car on level ground?