Learning from others mistakes

Originally Posted by PunchIt

I remember when I did a track event two years ago, one of the instructors said that the S2000s break free very easily. That anytime they were pushed to the limit and the driver lifted they snap spun.

Any ideas? Maybe something to do with driveline?

The s2k had some revisions recently to the suspension to help dial out the tendency to snap oversteer. Looking at that vid, as soon as the driver released the brake, you can see the left front almost immediately countersteering.

If the driver mis-matched revs bad enough to cause a spin, you'd see the rears lock up.

Originally Posted by elbert

Maybe too much braking during turn-in (like he was trying to trail-brake but not doing a good job), snapping the tail out.

yeap, you can see his brake lights were lit throughout the whole turn. My guess is he saw the M coupe in his mirror and didn't want to let him by, so ended up too hot in the turn and tried to still save it. Ironically, he didn't let off the brake until he had already started to spin...which was his second mistake. When you've lost it, you should have brake and clutch in. Frankly if he had gotten on the gas at turn in I think he would have made it...those S2000s handle great! Worst case he would have dropped two wheels at track out, which would have been better than almost getting T-boned at the apex. Kudos to the M coupe driver for having his car in control.

Originally Posted by PunchIt

I remember when I did a track event two years ago, one of the instructors said that the S2000s break free very easily. That anytime they were pushed to the limit and the driver lifted they snap spun.

Any ideas? Maybe something to do with driveline?

There is nothing wrong with the S2000 at all...its a pure driver's car. Yes Honda is revising the suspension and dialing in more understeer at the behest of the legal deparment I'm sure. This will help mask driver's mistakes (lifing/braking in a turn). Virtually any car would have spun if taken through turn 5 with the brakes on....braking should be done in a straight line.

Originally Posted by StahlGrauM3

Ironically, he didn't let off the brake until he had already started to spin...

He didn't do enough braking before the turn-in point and in conjunction with trail braking and the change in camber of the road, he managed to lose too much traction in the rear. This is a great example of why you should get your braking done before your turn-in point.

Not much to add that you guys haven't already said, except I also think he turned in too late.

That, combined with the braking mistakes you've cited = spin.

Next.....

Originally Posted by racerdave

Not much to add that you guys haven't already said, except I also think he turned in too late.

That, combined with the braking mistakes you've cited = spin.

I can't tell if he turned in too late, but what is apparent is that he didn't preload the suspension for the turn-in. It appears that he's snapping the wheel over and there just isn't enough preloading on the suspension for the turn.

Originally Posted by PunchIt

Next.....

I hate seeing clips like this one. I have my theory as to what happened but I want to read what people post first though.

Viper crash at PIR (1.8mb)

ugh what a crash. This one has me stumped. Pretty rare a car would swerve just like that for the wall.

Wild guess is either:
--he locked up the rears by mismatching revs
--something broke.

Originally Posted by sergiok

I hate seeing clips like this one. I have my theory as to what happened but I want to read what people post first though.

Viper crash at PIR (1.8mb)

Wow. It appears only one rear wheel locked up, so I'm guessing he mis-shifted from 5th...tried to get 4th and was really in 2nd. If so, not only does he have body damage, but also a blown engine.


SMG does have its benefits.

Originally Posted by StahlGrauM3

Wow. It appears only one rear wheel locked up, so I'm guessing he mis-shifted from 5th...tried to get 4th and was really in 2nd. If so, not only does he have body damage, but also a blown engine.


SMG does have its benefits.

Yes, SMG won't let you shift through a turn! The lateral G sensors know if the car is going through a turn and it won't let you shift. Very smart indeed!

From what I can tell, he was braking to get into the infield section but screwed up the heel-toe downshift thus locking up the the rear end. Ouch!

Originally Posted by sergiok

Yes, SMG won't let you shift through a turn! The lateral G sensors know if the car is going through a turn and it won't let you shift. Very smart indeed!

From what I can tell, he was braking to get into the infield section but screwed up the heel-toe downshift thus locking up the the rear end. Ouch!

Well SMG certainly would have allowed a shift in the Viper's situation...what it won't allow is a downshift that will exceed redline and blow the engine, thus locking up the wheels.

I guess I agree, the sound is rough so you can't really tell if the engine revs real high (miss shift) but it does appear by the single skid mark that he locked the one wheel up. Too bad. Any chance that the damage is just body work?

I don't get it, why would locking up the rear tires make it turn over to the wall? I guess it might turn when only one rear was locked up, but why would that happen when u make a moneyshift? shouldn't both rear tyres lock up?

--Andrew

Originally Posted by ayn

I don't get it, why would locking up the rear tires make it turn over to the wall? I guess it might turn when only one rear was locked up, but why would that happen when u make a moneyshift? shouldn't both rear tyres lock up?

--Andrew

Perhaps someone more technically knowledgeable can confirm this, but it seems that a car without a limited slip diff might have only one wheel lockup with an inappropriate downshift.

I am not familar with the track layout, but why would the driver be downshifting? The car was positioned in the middle of the track and does not appear to be slowing down for a turn. The car could be approarching some kind of turn on an oval track layout, but do you need to downshift for that?

I think it was set up as a roval--a road course inside an oval.

Originally Posted by StahlGrauM3

Perhaps someone more technically knowledgeable can confirm this, but it seems that a car without a limited slip diff might have only one wheel lockup with an inappropriate downshift.

Wouldn't the opposite be true?

A limited slip diff only allows the tires to rotate freely (independently) to a certain degree, then the 'limited slip' portion kicks in making both tires turn in unison (to a degree, thus the 'limited slip').

Another clip:

Spinning GTO (590k)

I'm looking at it (the Viper clip) and is it possible his left rear tire went down? I don't see a blowout

Originally Posted by scottn2retro

I'm looking at it (the Viper clip) and is it possible his left rear tire went down? I don't see a blowout

If you look closely, you can just barely make out the skid mark left on the pavement by the right rear tire early in the slide.

I asked a firend of mine who is a track junkie, here's what he said:

I didn't see any lockup on the rear tires early in the incident, so I don't think it was a "money shift".

I would guess the guy got on the brakes to start slowing for an upcoming turn, and also started to turn the wheel. He was braking too hard, and trailing throttle oversteer ensued (tail got light, and stepped out a little bit towards the driver's right since he was starting to turn the car to his left?)

Then it looks like his reflexes weren't fast enough to correct for the tail stepping out, and off he went towards the wall!

Originally Posted by ayn

I asked a firend of mine who is a track junkie, here's what he said:

Quote:
I didn't see any lockup on the rear tires early in the incident, so I don't think it was a "money shift".

I would guess the guy got on the brakes to start slowing for an upcoming turn, and also started to turn the wheel. He was braking too hard, and trailing throttle oversteer ensued (tail got light, and stepped out a little bit towards the driver's right since he was starting to turn the car to his left?)

Then it looks like his reflexes weren't fast enough to correct for the tail stepping out, and off he went towards the wall!



I just don't see enough steering input to create a trailing throttle oversteer situation. If you look at the front wheels just prior to hitting the wall, he is countersteering, but it seems to have no effect on the car's direction...leading me to believe that there was a rear lockup or tire failure or something that caused the car to dive directly into the wall like that. I'm going to check with a guy I know that has a viper and see if he knows about this incident. Curiousity has gotten the best of me.

I agree with Stahl on the Viper.

Something happened to lock the rears up.

In a kart, it would be like "sticking" the motor at the end of a straight: rears lock and you're around faster than you can blink.

I think it happens way too suddenly to be an overzealous trail-brake situation.

Also, I don't think it was a "money shift," as when I think of that, I think of it happening during an upshift.

It was either a mechanical failure (but there's no smoke) or a botched downshift like Stahl suggested.

Off to the GTO...

Ah, the GTO... a classic case of being "pushy loose" as the Nascar boys say.

Driver turned into the left-hand (last) part of the chicane slightly too early, was on the power early, then had to keep the wheel turned because he was 1) understeering or 2) running out of track. He should've been straightening the steering at that point, not adding or maintaining lock. The front tires bit, and snapped the rear end around.

So that line error, coupled with excess steering input and gobs of throttle (and the engine getting up on the cam) at the exit = the spin.