Oversteer and understeer info

[wadeh]

I answered this earlier, but I'd like to elaborate a bit on it.

Understeer is when your front tires lose cornering grip and the car does not turn as sharply as the front tires.

Oversteer is when the rear tires lose cornering grip and the car turns more sharply than the front tires. You can get the rear tires to lose grip two ways: If you apply to much throttle, they will lose grip and you get regular oversteer. If you lift off the throttle in a fast turn at the limit, weight will transfer to the front of the car. The reduced weight on the rear tires will cause them to lose grip. This is called trailing throttle oversteer.

If you experience understeer, you are likely to say "this car doesn't handle very well". If you encounter regular oversteer, you are likely to say "woo hoo!!!". If you encounter trailing throttle oversteer, you are likely to blurt out some curse words and need a change of underwear. If you are lucky, you won't total the car.

You can affect a car's tendency to understeer or oversteer by changing the suspension setup. Most (if not all) street cars are set up by the manufacturer to tends to some degree towards understeer because understeer is less likely to result in the driver losing control of the vehicle. In general, the less the tendency towards understeer, the better the car is considered to handle. If a car is neutral or tending towards oversteer, it is sometimes considered unsafe (see recent discussions about the Porsche Carrera GT after Paul Walker's death).

[eagle1]

Originally Posted by Normagene

I live on a Cul-de-sac, big ol circle, and I love ripping a few rounds, three or four usually, before whipping it into my driveway. I've yet to oversteer, but understeer like crazy, depending on the temp. 1.2 on the G Meter is my best. Where the road intersects the circle is where I try to really put down the power because I've got a much wider piece of pavement in case I spin out.

Anyway, I watched somebody's video posted here with an instructor in the passenger seat. Just this one little comment the instructor kept making greatly improved my performance. "EYES UP". I noticed I tended to look/focus directly in front of the car instead of looking up ahead. Also I'm learning to keep my eyes where I Want the car to go and not where the car is going.

If she starts to slide off track/course, don't look where she is heading, but focus on where you want her to go. It's pretty amazing but it's like I automatically respond accordingly. Whether I need to let off a little, brake a little, or accelerate a little, looking where I want the car to go is key!

If you fixate on something, let's say you're sliding towards a tree or wall, and your eyes lock on that track, THATS WHERE YOURE GOING TO GO, instead you have to ALWAYS LOOK WHERE YOU WANT THE CAR TO GO!!!!!!...... Believe me its easier said than done. Panic can set in very quickly and you can freeze up instead of focusing on where you want to go. Big empty lot = Practice Practice Practice.

Normagene were did you find the vid you talking about. Before the winter cold set in i manage to put about 2500 miles on the camaro. One thing i notice was that it has and unbelievable amount of traction in the hot weather. Some time you could hear the sand being pick up by the tires and hitting the wheel well! This reminded me of the slicks on my drag car coming back on return lane. As for letting off a little,braking a little or accelerating a little sound like a balance thing. I need to pick up on that better like a driving school. Right now my driving knowledge tool box is made up of all the crazy thing we do on pavement or snow. None is road course knowledge. Thanks for info.

Originally Posted by wadeh

I answered this earlier, but I'd like to elaborate a bit on it.

Understeer is when your front tires lose cornering grip and the car does not turn as sharply as the front tires.

Oversteer is when the rear tires lose cornering grip and the car turns more sharply than the front tires. You can get the rear tires to lose grip two ways: If you apply to much throttle, they will lose grip and you get regular oversteer. If you lift off the throttle in a fast turn at the limit, weight will transfer to the front of the car. The reduced weight on the rear tires will cause them to lose grip. This is called trailing throttle oversteer.

If you experience understeer, you are likely to say "this car doesn't handle very well". If you encounter regular oversteer, you are likely to say "woo hoo!!!". If you encounter trailing throttle oversteer, you are likely to blurt out some curse words and need a change of underwear. If you are lucky, you won't total the car.

You can affect a car's tendency to understeer or oversteer by changing the suspension setup. Most (if not all) street cars are set up by the manufacturer to tends to some degree towards understeer because understeer is less likely to result in the driver losing control of the vehicle. In general, the less the tendency towards understeer, the better the car is considered to handle. If a car is neutral or tending towards oversteer, it is sometimes considered unsafe (see recent discussions about the Porsche Carrera GT after Paul Walker's death).

Wadeh thats very good info. I kinda understand it better now. A light bulb went off when you explain the seriousness between understeer and oversteer. I have been in situation where the brakes are lock, steering turn full lock and car is still tracking in the wrong direction. Not until i let off the brakes would it come back. I also felt the car shifting mass weight all over the place as it start to go back in the right direction. I had and extreme case of oversteer in a 67 chevelle with stiff suspension and N50's in the back. Just as i pass under and intersection after a heavy down pour i felt the rear end brake lose and start to go counter clock wise to the right. No big deal, been there done that before, but this time it didn't catch and before i could finish that thought i was looking in the direction i had just came from. I was traveling north on a six lane road in the middle lane. I cross the medium and all three north bound lane and ended up in this parking lot of a tire place and i knew every one there. I was very embarrass! I had so much sod on top of the car and under the car it was crazy. So if i had a choice at which one to deal with i would pick understeer. Thanks my friend.

[Norm Peterson]

Originally Posted by eagle1

Todd thanks for sharing your info here. You would think that on the skid pad that because of the speed the weight is shifting to the outside and lifting or unloading the inside tire so the lost of traction.

That is of course happening, but the way the car responds to that depends (more or less) on whether more load is transferred across the front tires than across the rear tires (understeerish) or vice-versa. Adding power, or engine compression braking, or braking with the service brakes changes the overall picture . . . and the change can result in either more understeer, less understeer, or oversteer.


Norm

[eagle1]

Originally Posted by Norm Peterson

That is of course happening, but the way the car responds to that depends (more or less) on whether more load is transferred across the front tires than across the rear tires (understeerish) or vice-versa. Adding power, or engine compression braking, or braking with the service brakes changes the overall picture . . . and the change can result in either more understeer, less understeer, or oversteer.


Norm

Norm just finish watching this vid and i seen just about everything you talk about and then some. All the guys are basically saying the same thing in there own words. I cant get over this guy ability to drive in wet condition.Big brass ones! He did some thing that i cant understand yet. At one point it look like the car drifting around a turn but the steering input didn't jive with with what the car was doing! Crazy!

http://youtu.be/hCJ-WfPdG8c

[Dr. Evil]

Understeer: Driver is scared

Oversteer: Passenger is scared

Theres a lot that goes into this. Power, suspension setup and alignment, car weight distribution, tires (size and available grip) etc.
You really want something that'll bake your noodle? A Porsche 930 is an absolute beast to drive. Rule number 1 is to not let off the gas in a turn. Most 930s (and 911s for that matter) will oversteer horribly in a turn if you let off the gas. A 930 will understeer getting on the gas coming out of a turn. I got to drive one a friend had a while back and it was strange coming from a corvette.

[jshaf]

the main reason I got ride of my 2003 3.5 Altima, was fun as hell to drive in the summer but in the winter that thing would do a 360 in the middle of the road at the drop of a hat. scariest damn car I ever owned in the winter.

[Normagene]

What I find so impressive in that video is in the speed/reflexes of the driver. He makes the corrections instantaneously. Damn good driving.

[eagle1]

Originally Posted by Dr. Evil

Understeer: Driver is scared

Oversteer: Passenger is scared

Theres a lot that goes into this. Power, suspension setup and alignment, car weight distribution, tires (size and available grip) etc.
You really want something that'll bake your noodle? A Porsche 930 is an absolute beast to drive. Rule number 1 is to not let off the gas in a turn. Most 930s (and 911s for that matter) will oversteer horribly in a turn if you let off the gas. A 930 will understeer getting on the gas coming out of a turn. I got to drive one a friend had a while back and it was strange coming from a corvette.

Sounds like a handfull but fun.

[eagle1]

Originally Posted by Normagene

What I find so impressive in that video is in the speed/reflexes of the driver. He makes the corrections instantaneously. Damn good driving.

Thats what im saying! I was looking at what he would do with the steering when things got out of hand. He would correct so quick like a ninja and almost punish the car for acting up by stabbing it harder. He's a animal behind the wheel! It almost looks like a dance.

[Norm Peterson]

Oversteer can be pretty damn spooky for the driver if conditions are such that either adding throttle or dropping throttle makes it worse. Been there (and once was enough).


Norm

[woodside783]

The alignment can help with the car pushing or understeering. With just 2 degrees - camber my car stopped understeer.

[eagle1]

Originally Posted by Norm Peterson

Oversteer can be pretty damn spooky for the driver if conditions are such that either adding throttle or dropping throttle makes it worse. Been there (and once was enough).

Im definitely going to learn how to crawl before i learn to walk or run!
Norm

Originally Posted by woodside783

The alignment can help with the car pushing or understeering. With just 2 degrees - camber my car stopped understeer.

I seen on here where a guy from Cali put up some good info on 4 wheel alignment. Will keep that in mine. Thanks