Falcon

Hunting for ideas on what caused this Cobra to flip at VIR. I know the short wheelbase doesn't help. It could have been some mechanical issue.

It's just odd since we don't see many cars do this.

Any ideas from the video?

I'd like mine over easy, please!

John Shiels

nasty luckily I have no experience to tell you! Was he OK? Just to fast and when he lost it for what ever reason it grabbed. He could have turned the wheel to recover the wrong way also.

Mikelly

I've seen that before on live axle cars. The spring compresses only so far before the force "springs" and digs in. That energy has to go somewhere and you see the results...

Hope he was ok...
Mike

AU N EGL

Norbert and Jami were at that event too.

That woman driver, crashed her Crbra, and their Viper. then they parked their Ford GT.

The couple refused instructor help and was apparent they had no on track experience, just deep pockets.

ghoffman

Apex'ed too early, common mistake.

GO_BLUE_VETTES

Looks like the car pivoted on the left rear tire. As the car spun, right before it flipped all the weight was on the left hand side = grip. Looks like it flipped right at the instant where the left rear tire was perpendicular to the direction of travel. The track is just starting downhill where the flip occurred too.

Did the roll bar stay intact? The video is quick, but it almost looks to me like it collapses a bit and you see parts moving around (helmet).

Z06cool

This was a TrackDaze event. I was there but didn't see it happen, only saw it driving by. That was ALOHAC5 behind the camera car. She seemed okay but shaken afterwards.

RAFTRACER

Besides the fact the person "lost" it, the car looks like it was really softly sprung(especially in the rear), that coupled with high aspect ratio tires and alot of roll resistance (bars) is a recipe for these things. I once saw a old Datsun 2000 roadster do almost the same thing on an autocross course. The car had Hoosier bias-plies, high rate roll-bars, and super soft springs. Car bicycled in mid corner and ended up sliding across the parking lot on its rollbar (thank god he had one). Guy was screaming "get me the hell out of here", myself and a few others blasted the car right side up and the driver was OK depsite his beautiful little car being destroyed.... He has since rebuilt the car and had been competing with a completely different suspension set-up.

Miaugi

High center of gravity probably didn't help, I wonder if it was a big block car?

parkerracing

That caused the spin for sure, but the sudden bite and flip?

beerkat

The way the car pivoted I think the front right brake graped and the car rolled

AU N EGL

Driver also put a Viper into a wall that day too. IIRC

ghoffman

Same deal here with a Suby at Lime Rock. We have all seen this video, but it is a good reminder.
http://www.youtube.com/watch?v=n7Q5ZeV5ud0

Tintin

I had a Superformance Cobra for about 5 years and in that time I knew of at least 5 of these cars that rolled over in bizzare circumstances. As stated above, the giant tires do not help the situation one bit. The high end fakes are all independently sprung, the live axle is only the Factory Five car which is what you would expect in a car you can build for less than $40K. These cars have absolutely diabolical handling, like they did in the 60's and are completely unsafe in a wreck of any kind as you have no doubt seen for yourself in the video. The centre of gravity is very low, the shape of the body makes the car appear larger than it is. It is the same size as a Miata but about 500 pounds lighter and about 300 more hp .They dig in like that and go over because...

The cars typically have 295 to 315 aspect rear tires and 275 to 295 fronts. The purists use 15 inch wheels and thus end up with a 60 aspect ratio. Since the cars only weigh between 2100 and 2600 pounds total, you run only 20 pounds of air on the street and maybe 25 on the track. You get a little sidewall flex.. .. to say the least. I drove one on the BFG drag radials and it cornered like it was on a rubber band, turn-snap back, turn snap-back, yikes! I have seen one of these cars roll at Thunderhill at less than 25 mph while going downhill from the hilltop hairpin, and I absolutely could not believe my eyes. Neither would you, it seemed impossible at that speed.

Here is a picture of Tintin in that same corner from the Superformance website, notice how the tires are not deformed, they have 24 pounds of air...



Here is a link to their website, the other pic is of me too, photoshopped to cover the beige grass up there.

http://www.superformance.com/MKIII.aspx

That was the only day that I took that car to a high speed track and I can tell you that these things can really fly in a straight line but it takes a ton of skill to corner them. I hit 140mph on the straight at Thunderhill at half track and it was not a stable experience at all. I drove 140mph in endurance races in pouring rain many times - it was like that. This was the only time on the track ever that I felt like I could be hurt in a car. I only did 3 laps and came in, that was enough . I only took it to the little track at Firebird one other time and confined it to street driving after that. I intend to collect my 401K and social security.

Anyone who takes one of these things onto the track without a full cage and arm restraints is a fool IMHO.

I have a question, why did the following (camera) car slow down and drive off the track? That is almost as scary and easily as dangerous as that toppling action. When stuff like that happens, hammer it and be somewhere else before the pack joins in.. Just a word to the wise...

racerjon1

Amung all the things posted above.. light car, grippy tires, roll center, etc -

IF YOU SPIN - BOTH FEET IN.

He lets off the brake as the car comes around, and now he has a car with its wheels rolling and turned... Next time at the grocery store push your shopping cart backwards, watch how easy it turns. tight turning radius + sticky tires + spin momentum = not good.

Seriously, I think if he keeps his foot on the brakes the wheels stay locked and he just continues to spin. I am sure I have heard an instructor or two say something about that.


Jon K

Tintin

You are correct that you will continue in a straight line with the wheels locked but in that car you are still going to need a ton of luck not to go over. If she had locked the wheels and touched the grass , the result would be the same.. I know someone who spent 5 months in an ICU from a crash just like that one, this person must have swallowed a horseshoe before they went out...

racerjon1

Yea, there were a lot of factors there, but she made sure she was going to flip when she let off the brake right as the car was coming around..

if a stunt driver was going to make sure that car flipped, that's how it would have been done.

Jon K

robvuk

That's pretty much my assessment as well. If you look at it frame by frame, you can see the black rubber marks stop when she starts going backwards. At the same time she let off the brakes, it looks like the wheels get turned to her right, causing the front end to whip to her left while moving in reverse.

Solofast

It would have been a lot harder (or very unlikely) for the car to go over if he(she) had kept the wheels locked. If you watch closely, what happened is that the driver spun and was actually going backwards for a bit. With the wheels locked it would have likely backed off the track, but it wouldn't have gone over. In this case, the front wheels were still turned as the car was rolling backwards, the effect of the wheels being turned is like having a huge slip angle at the back of the car and none at the front and the most rearward part of the car (what is normally the front) is now fast trying to pass the part that is ahead of it. Since all the wheels were turning, they can hook up and grip big time, which is what happened. If the wheels are locked you are sliding the friction isn't there to roll the car. These are not real wide cars and the CG is not that low so you get a propensity to roll. I do agree that if the car went off the track totally sideways the probably same result would have happened, but not locking the wheels and having the fronts turned is what caused it to hook up violently and go over on the pavement. Our cars are much less likely to roll, but there is most certainly a lesson in there...

I went to college with Tim Chitwood, we got to be pretty good friends, and he said that if you are going backwards at speed you work really hard to keep the wheel straight. If you want to spin back around, he said all you do is jog the wheel a bit to one side to break the front tires loose, and then straighten it back up real quick and the car spins back around. He was pretty nonchalant about it, but then anybody who could "bicycle" his car for the length of the Homecoming parade (he was the leadoff vehicle in the parade) had car control down, going forwards, backwards, or edgeways...

Learn to spin! both feet in is the way I learned it...

FasterIsBetter

From the beginning of the video, the Cobra was not on the racing line at all. Driving the track like it was the street. Looked like she hit the brake hard when she realized she had to go right, which broke the rear end loose, and then just spun out. Once she was going sideways, the wheels caught and over she went. The trailing car did a nice job of braking in a straight line and getting off the track there.