A few members have been asking about over steer, and what causes it. I found a great example of a particular type of over steer, called snap over steer in some of my track footage.

Over steer is generally caused by the driver applying more steering input than the rear axle of the car can handle in a particular situation. Rear of the car looses grip before the front, which induces the rear to come around.

Snap over-steer is caused by an over correction to initial over steer, or by holding the correction too long. Remeber CPR from driver's ed? Correct, pause, recover. But don't pause for too long, or this happens.

 

I saw it happen to a Gen 2 MR2 at AutoX once. Apparently they were really bad about that.

 

I've found this is more likely to happen when I'm on cold tires. As they heat up, oversteer tends to become more progressive.

Good post!

 

The video shows the classic mistake made by inexperienced drivers. When the car gets loose and the tail starts to drift, the worst thing you can do is get off the throttle 100%. Depending on how bad the car has gotten out of shape, it can be controlled or completely corrected by gently modulating the throttle to neutral to extremely slight decel and staying with the counter steer. You might still go off in the beans but you're still partly in control and still heading in the right direction when you finally regain complete control of the car. If you're too far out of shape and physics has gained the upper hand, just stay in the throttle and force the car around. In that mode, once the car is 180 to your once intended course the forward spin of the tires helps brake the car. If the throttle is released in a drift, the back end either snaps back uncontrollably as shown, or depending on how far gone you are, will go all the way around again, uncontrolled, often causing the car to back into the wall if there is one. I've seen it happen time and time again up at BIR...some real nice and expensive cars relagated to the scrap yard.


I guess the lesson is: Learn your car, learn car control, learn your person limits!


John

 

huh, learn something new every day . . . I did not know that was "snap oversteer" I thought that was called "over correction"

I thought "snap oversteer" was when oversteer happens extremely suddenly like the rear "snaps loose." I had that happen to me once on the track, accelerating out of right hand turn (turn 2 at Thompson for those who are familiar) and I was in the grass on the inside of the turn before I knew what happened.

 

Oh Snap! Glad you and the car are fine.

I'm of the opinion snap means the car rapidly switches direction, but I guess any kind of sudden traction loss of the back end in a corner could be it.

 

that was definitely an "oh snap" moment, sliding across the grass at about 70, looking forward to see what I was going to hit . . . luckilly came to a stop about 20 yards before the ditch with no damage other than my ego and a car full of grass and a black-flag trip to pit lane to explain my mistake, LOL

 

That looked like an S2000... Drove like an S2000, was it an S2000?

 

Interesting place to have that happen at Thompson. Most spins I've seen are turn.. 5 I think, the transition onto the oval under the bridge. Glad you didn't have any contact with a wall!

 

Yes it was. Wearing really aggressive tires too.

 

People were saying that is where you left your cooler and you meant to turn in like that??