Scottybob

iTrader: (3)

After looking at the video from this thread I ended up with a long winded answer that is a better fit in this forum.

I watched the vid a couple of times and I think I've figured out what happened.

If you watch the tire line (for lack of a better term) from the car in front you see a point where there is no tire line. This indicates that there is deep standing water at that point. The driver apparently did not recognize the standing water, or else he would have brought the steering and throttle to neutral as he crossed the puddle. What resulted is a perfect example of why we should always be concerned with hydroplaning and know how to handle the situation.

What I believe you see in the video is the driver accelerating and turning on a very fast part of the track. He hits the water, which instantly brings the traction of the tires to basically zero. The momentum of the car caused it to continue to turn resulting in snap oversteer. The big lesson you can take from this video, and this applies for both track and street driving, is do not be turning or speeding up or slowing down when you are going to hit standing water. Nasty things will happen. Neutral steering - neutral throttle and you will still be in control on the other side of the water.

I feel the primary cause of this accident was that the driver had a good bit of steering input as he hit the water. The car definitely had some lateral forces applied. Add to that it sounded like he was off the gas, or at least feathering the throttle pretty good as he hit the water. This transfers weight to the front wheels and gives them a great bite when they come out of the puddle. Guess what’s happening at the back of the car when the fronts hit relatively dry pavement and pull the front of the car hard in the direction of the steering input? The rear tires still have almost zero traction. The back of the car keeps going in a straight line because the rear tires have no way to oppose the rotation of the car.

I feel really sorry for the driver. That was a long 4 second ride with noting he could do to salvage the situation. We can pick up on one driver error in the video. As he looses traction and begins to counter steer he gets completely off the throttle. This only exaggerates the problem by taking weight off the back wheels. He needed to stay in the gas just a little to try to keep some weight and traction at the rear.

racerjon1

First, thanks for posting this here. I think we can discuss this here without people laughing, that hurt to watch, and the other threads were lacking in maturity.

First thing that I saw, which isn't well taught anywhere is using a rain line. In the early corners he is on the "normal" line. On a well used racetrack, the racing line gets polished and smooth. (think of water running over a stone in a river) Cars do the same thing to the asphalt. When it gets rainy, the surface holds water on the race line because the surface has less "depth" also.. the oil and such that gets dropped on the rain line can be brought to the surface.

This is where the "rain line" comes in. You actually want to move your car over so that you are not on the polished shiny part of the track. There will be less standing water, rougher surface, and hence more grip.

If you have a long sweeping corner, the rain line is usually on the inside, people going for a late apex usually polish the outside. If its a short tighter corner, then the rain line is usually on the outside. People cutting across the corner tend to polish much of the inside in this case.

Many times you dont have to be all the way off line, just a few feet. Sometimes, you do want to be all the way off, avoid concrete patches in the wet. (Watkins Glen, Road America, and I think Summit point have those)

When you look at his video, he is on the line and he actually loses the car at the 2nd water flow across the track. Its very possible that he hit the first one, car started to hydroplane, and then caught the 2nd one before it settled. This is probably why the different throttle response and steering input.

From what I can see, my line would have been on the inside (long sweeping corner where normal line is late apex, so I would drive inside of it) and then as i came to the two water flows, I would let the car straighten out to drive across them. Like in the dry, your tires can only do so much: accel, braking, cornering.. in the wet the same thing. If you know about a flow, cross it straight, and either braking, or accelerating, but not turning at all if you can help it.

Aside from a guy tearing up his car and probably being pretty sore, the "worst" thing i saw was actually after he had already lost it. He kept his hands on the wheel. Thats a good way to break your thumbs, especially since he grabbed it tighter.

A tip: If you are cussing cause you know you are about to hit a guardrail/wall.. you have enough time to take your hands off the wheel.

In one of the other threads someone said "I will never track my car in the wet" I don't agree, and I think that that is where people should go to learn wet driving, the same as dry performance driving. I feel bad for the guy, I hate crashes, and I know how expensive they can be. But you are still not going to get a safer place to learn about situations like that.

Jon K
www.seat-time.com

JoizeeX

very good posts you guys thanks for the info. some ppl in the other thread were making me sick. my question is. when he was trying to countersteer, do you think he didn't turn the wheel enough? it seems like he only turned it about 100-110 degrees. i've skidded out in the rain before (not on a track) when i was making a left turn from a stop and got on gas too soon. i was new to the car and didn't expect awd to kick out the rear so much when boost kicked it. the car rotated about 45 degrees, i turned the wheel into the skid about 100 degrees and let off gas halfway. the rear finally got grip but i think it's because i didn't countersteer enough, the car went forward instead of straigtening out and i rode onto a 6" curb
so do you think in his and my cases we shoud've applied full lock into the skid? and then as the car was straightening out unwind the wheel back to center? it would seem to make sense because when the front wheels aren't turned as much during a massive skid, the front has lateral traction, while rear doesn't, so the front becomes the pivoting point for the car. if the front wheels are turned more, they just roll in the direction of the skid and don't provide lateral traction and the front is no longer the pivoting point. i know this sounds pretty obvious, as this is the physics behind correcting oversteer, but i just wanted your input. thanks.

racerjon1

Thank you for the compliment, I am glad we can have a productive discussion about it, If someone had to crash, the best thing we can do is learn from the mistakes.

When he was trying to countersteer, do you think he didn't turn the wheel enough?

It's hard to say. Each spin/skid is different and there is no set amount. I will say that this does happen.. I try to describe it as the shopping cart effect. When you "drift" a shopping cart in the grocery store. (don't deny it, you know you have) Notice the front wheels turn into the "skid" the perfect amount. (we could discuss caster here but for this we will keep it simple) The simple point is, cars do the same thing. Its why we teach a relaxed grip on the wheel: "thumbs up driving." Sometimes you have to let the car do what it wants, in a slide sometimes just relaxing the car will do a lot of the work for you. I am not advocating taking your hands off the wheel, but I am pointing out how you can correct into a skid as taught, but actually be holding the car back. (which is why in both yours and his cases it MIGHT have affected the outcome.)

The best thing to do to help avoid this is to keep looking ahead, and not worry about exactly how much you are turning the wheel. By looking ahead you get a much better representation of the actual attitude of your car, and have much less of a chance of over, or underreacting.

and then as the car was straightening out unwind the wheel back to center?

Yep. This is what actually causes "overcorrection" its when the car goes back straight but the wheels are still pointed into the "corrected" direction causing those horrible feeling back and forth motions till you a) get lucky and save it b) go ahead and spin. (A skill I had the enjoyment of Randy Pobst teaching me at Road Atlanta. Good thing too, I went flat through turn one the next session and used the "****** back" from having a horrible 120 mph off in a Formula Ford.)

the rear finally got grip but I think it's because I didn't countersteer enough, the car went forward instead of straightening out and I rode onto a 6" curb.
so do you think in his and my cases we shoud've applied full lock into the skid?

It is so hard to decide what exactly was right in this kind of situation on the street, you had steering inputs, throttle inputs, and then there is the very inconsistant surface of a street in which you might have found a slightly less wet spot that changed the behavior.

Steering into the skid will give it grip back of course, getting the tires only doing one of their three things. Letting off the throttle also put more traction on the front wheels (weight transfer forward) which usually has a tendancy to either just shoot the car in the direction the wheels were turned. (like an overcorrection, but not always in the other direction if you were not turned enough) Again, without being in the car that one is much harder.. maybe by answering the rest of this it will help.

it would seem to make sense because when the front wheels aren't turned as much during a massive skid, the front has lateral traction, while rear doesn't, so the front becomes the pivoting point for the car.

Exactly, which, like you say, is why you have to "turn into" the skid. You are really unwinding the wheel and letting the car catch back up straight. (same kinda reason why you can unwind to stop understeer too..

I will run through some basic skid control.
First there are two types.

1) Throttle on: (Powerslide, drifting, etc.. ) car is turning, tires cant do as much turning and throttle as you are asking, and the tires break loose. (FWD this means push, RWD/AWD this means loose)
How to fix it: Don't add anymore throttle. Turn into the skid as much as needed. Don't lift off either though. If you do, the car slows, weight goes forward, front gets more traction, the already sliding back looses traction and goes ahead and finishes off the spin. So.. steady throttle, slight correction.

2) Lateral g overload: usually this is corner entry sliding. Turn in, car rotates.
How to fix it: Get back in the throttle.
You save this one by rolling into the throttle because it transfers weight back to the rear, and that weight helps with traction. If its a fast corner (no braking just a lift) that's when you run into people wanting to lift more and just sends them spinning. (might very well be what happened to our poor friend in the Subaru, many corners in the wet become "fast" non braking corners.)

Warning: sometimes both these types of skids are just too much too fast. In these cases you just cant catch it. Its a harsh fact of playing on the edge with an insane amount of variables. its why its best to play at Autocrosses/skidpads/track days where better safety is in place.

Jon K
www.seat-time.com

vegasboy301

iTrader: (9)

here is the puddle i heard you mention

JoizeeX

thanks racerjon1. i've read much on the subject before and it always helps to have another input to grasp the whole picture. playing rally games also helped me a lot to understand how gas/brake/lift affect if the car is gonna tighten the corner or wash out more. i recently bought the new logitech wheel with 2.5 lock to lock turns, partially for the fun of it, partially to learn how to steer a real car in a skid because i felt that no matter how good i got in racing games, all my reflexes and inputs didn't help as much because in performance driving i'm mostly used to analog thumb stick and sliding throttle. the idea might sound kinda silly, but i really did learn much in a safe environment where my car wasn't in danger. the difficult part is getting used to turning it to lock quickly and then centering it back at a proper pace with all that force feedback happening.

i've spun my integra at an autox once after slowing from 55mph (went in too hot with trailbraking, should've braked earlier) because i didn't use "****** back" quickly enough, so as the car slowed down from sliding it snapped the other way and at that point there was no forward motion left to catch it with throttle application. another reason why i would never upgrade just the rear sway bar, i rather have some understeer just so i can brake harder with a safety margin. although that's a whole other debate, feel free to comment.

oh and i drift shopping carts ALL the time

in the vid it looked like he went off the other guy's tire marks for a lil bit and then tried to get back into them by twitching slightly to the right, which then kicked out the rear, courtesy of the puddle. or so it seems like to me.

racerjon1

I am glad I am not the only one terrorizing soccer moms at the grocery store.

The video game thing works.. it teaches you the looking ahead, and many of them have good enough physics models to create some ida of weight transfer. I had a student last year who came out in a CRX, engine swap, etc.. right off the bat starts running good times.. really good times.. I knew he had only autocrossed twice, and i was very surprised when he came in and told me "its pushing on corner entry, so i went up in the rebound setting of the rear shocks so i can carry a little more speed into the corner, if it doesn't work, i will probably drop the front rebound next session.." (which is a good set of adjustments for what he wanted)

I asked him "where did you learn all this?"

His reply: "I play at lot of Gran Tourismo."

As far as upgrading only the rear sway bar, especially on FWD.. I have a decade of autocrossing and roadracing CRXs.. i usually run with no front sway bar and the stiffest i can get in the rear.. As i would describe it "crash it on corner entry, save it with the throttle" But, you really have to be on top of the cars, its faster that way, but its tough to drive. Even the times i ran front bars, the rear would be a LOT stiffer...

As far as being on the tire tracks, its hard to tell if he is off and getting back on, or the car is already darting across the water, I can see both places where there is a break in the tracks, that I believe are the water flows, and he goes over one, then right after he goes over the 2nd the car takes off. To me.. it just looks like a reason to be on the rain line and cross those flows with the wheels straight.

Jon K
www.seat-time.com

Scottybob

iTrader: (3)

Dont be afraid to track your car in the wet. You learn a great deal about car control at much slower speeds in the wet. My lesson for wet weather usually goes something like this:

-Assess your equipment and conditions. You obviously don’t want to go out in a hurricane on slicks. The combo you want to avoid is coupling big standing or flowing water with no tread. If it looks like you might have to bum a ride home from Noah in the arcmobile, and you don’t have some full tread tires for the car; you might want to wait till it slacks off a bit. Dry tires on a damp track are fine. Personally my favorite driving condition is a well drained, consistently damp track with a light drizzle of rain. So I can run dry tires, but not have to worry about standing water. (If we are really lucky the track hasn’t been run in the dry)

- Look around and enjoy. See how many fewer people are on the track (whimps). Lots of free track space with no other cars to worry about, right? We are hopefully doing this for the first time at a DE type non-competitive event. To get your feet wet not having to constantly look out for traffic is a good thing.

- Pick your battles. Lets give up those 120mph sweepers with the retaining walls just off the white line, and find a couple of slow corners with good run off. Drive at a prudent speed around the rest of the circuit. However, do not relax your brain on track. I’ve heard many a wreck story starting out with “I wasn’t even pushing the car.” Pay attention.

- Begin to explore the limit. See how those brakes work in the wet. Find a spot, maybe the braking zone on one of our nice safe corners (No turning while trying this, please). Brake early and see how much force you can generate before the ABS engages or a wheel begins to lock up.

- Now we’re having fun. (This bit is the way I got comfortable in the wet, results and opinions may vary) Pick a braking point for your nice safe corners where you can bring the car to a very controllable speed by using a lot less force required to lock the brakes. Gradually build your speed through the turn by using the same braking point, but less brake force. As you slowly build up your entry speed you should begin to get understeer, correct as needed. Congratulations, you have just survived your first wet track skid.


From this point on it depends a lot on what kind of car you are driving, and what works for you when trying to approach your limits. You will notice a couple of things right away. First handling characteristics are exaggerated by the wet conditions, more understeer in a car prone to understeer and more oversteer in a car prone to oversteer. Second you will find that there is a better line than the dry one you have been using.

Dont be afraid of the wet track its a lot of fun.

racerjon1

^ ^ ^ Good post.

My first time in the wet went like this:
Daytona Florida, Formula Ford.. great bright sunny florida day. Race starts, lap one and two cars get together coming off the banking in NASCAR 2.. both cars lose all 4 corners..

50 min black flag later and we are about to head out on track when we get one of those great florida thunderstorms..

Drivers: "Can we go change to rains?"
Officials: "Nope, we are already an hour behind, go race."

I kept my head clean, passed a lot of the guys going off, and finished 4th.

I absolutly LOVE wet racing now. Doesn't matter what I am in.
two biggest things to rememebr are:
1) relax. lots of people beat themselves in the rain because they psych themselves out.
2) you dont have to be "pushing the limits" the same way you do in the dry. Be consistant, be smooth, be calm.

Jon K
www.seat-time.com

JoizeeX

i noticed that driving in the rain, on or off track, i just basically have to be a lil more conservative and things will be just fine. i decided not to experiment in the evo just yet, but i push my teg in the rain pretty hard at times (provided there are no cars on the streets that will be in my way). it's very predictable with power-understeer when going around corners and sometimes i floor it just as i'm straightening out, to get the feel of the traction limit, then let off to feel the tires catch the pavement again. and if i'm feeling brave that day, i'll do a hand brake 90 degree turn when no one's around. my teg rides on about 50% tread on dunlop sp8000 ultra high perf summer tires. they suck in the wet (since the compound has hardened after 2 yrs), mostly in accel and braking department, the lateral traction is still ok especially with the car being lowered => negative camber and i've had no hydroplaning issues even at 80mph on wet roads with drizzle (fo' shizzle).
once i learn the limits of the evo, i'm gonna feel a lot more comfortable with it in the rain. i wanna take it to an empty parking lot at night in the rain, just to feel braking and turning limits. i'm actually more compfortable in the teg taking tight exit ramps at 60 than in the evo.
racing games have definitely taught me fine throttle control, racing lines, some passing techniques and some car tuning, as well as how not to go in too hot to prevent understeer on factory setup cars.

Kayaalp

iTrader: (1)

Standing water is a whole different ball-game. Once you hit it you really can't do too much to improve things. In fact, anything you do (especially harsh inputs) will probably make things worse. If the driver doesn't anticipate standing water, then he doesn't have many options. Even if the driver in the vid hadn't lifted, he still would have wrecked the car.

The only way to deal with standing water is to know it's there and set the car up WELL before-hand so that you skate straight across it (as scottybob says) with neutral throttle and neutral steering. You need a light touch on the wheel and you have to fight the temptation to "do something" when the car starts moving around under you: just be zen...let the car skate...then take control once you're out of the puddle.

I really sympathize with this video. I wrecked a BMW at Le Circuit mont-tremblant when I hit standing water in Turn 6 (a very high-speed left-hand sweeper). The track had just been repaved and it was my first time driving the "new Tremblant" in pissing rain. I didn't see the standing water and hit it with significant steering lock and almost full throttle at the top of 4th gear (maybe 80-90 mph). I hit the tire wall HARD and the car was finished.

Emre

Kayaalp

iTrader: (1)

Grow some *****.

Driving in the rain is absolutely the BEST way to get good at high-speed driving. You need to be smooth and delicate in your inputs. You need to be very sensitive to what the car is doing. HP doesn't mean much. And you get to see how your car really handles. I remember one season where I had maybe 8-10 track days in a row in hard rain in my E30. My driving improved SO quickly I was amazed.

Anyone can throw R-compounds on a car like the Evo or STi and post quick lap-times in the dry.

Emre

Scottybob

iTrader: (3)

Emre's first post reminded me of something I was going to comment on.

The kind of snap oversteer you see in this video is almost impossible to recover from. That poor guy really didint have much of a chance.

In theory he could have tried to let the car continue to rotate to end up going backwards or do a complete 360. The hope being that if you can get either end of the car pointed in the direction of movement, then at least you have some ability to use the brakes.

A lot of DE programs teach that once you know you have lost control of the car you should "clutch in brake in" a technique that I do not aggree with. This is good for novice drivers who often get themselves in trouble with post traction loss inputs. Once some skills begin to develop drivers should try to leave the track in a straight line (prevents rollovers), get the car under control, and contiue. If its obvious that you are going to hit something hard, then for god's sake do SOMETHING.

The driver in our video had about 4 seconds from loss of control untill he hit the wall, plus time to start screaming. He really didn't do anything after his initinal correction, and ended up with the worst kind of hit (drivers door)

Slovak

iTrader: (4)

Being a professional driver of the 18 wheeler type for 10+ years prior to changing careers, I also was a driver trainer and taught in Michigan at Eaton Fullers (transmissions) test facility on their skid pad, I can tell you from experience that when one hits water that causes hydroplaning, the best thing to do is first let off the gas and do not hit or tap the brakes, then you must counter-steer in the direction your *** end is sliding, BUT, not giant turns, tiny choppy turns of the wheel in the direction that the *** end is sliding. When I say tiny I mean like half inch at a time turns quickly until you "feel" the *** end sort of not sliding any further, then counter steer the opposite direction to bring the *** end back around. I have tested this in both 18 wheelers, and my car, a Ford Taurus at the time. It does work if done properly. If you live in a snowy area try this in a huge empty parking lot when up to about 20mph, mash your brakes hard enough to cause a spin out then release them and practice the steering method to recover from the spin.

racerjon1

This is the "double down" technique, and it should be taught.

When you double down you continue in whatever direction you are going in a straight line. (direction of travel wise: rotation may continue)

Why its good: Your movement is predictable. If you are on and off the brakes while spinning, your car does stange things, none of which at that point are really controlled.

If you are chaning directions at odd intervals, then it makes it harder for anyone behind you to avoid you, which is more dangerous than you alone hitting a barrier. (less people at risk if nothing else)

Also.. if you change direction while spinning, and you are in soft sand, this increases your risk of rollover.

As you noted if you do know you are going off, then sure... drive straight off, but the double down technique is for a car that you have lost, and is spinning.

Jon K
www.seat-time.com