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03 cobra toy
10-02-2006, 05:18 PM
Happy reading :D

Understeer and Oversteer

When discussing the handling characteristics of a vehicle, the words "oversteer" and "understeer" come up all the time. Here's a basic description of what those terms mean, and a little bit of theory about why particular cars exhibit either oversteer or understeer.

Definitions:

"Understeer", also known as "push", and "dammit, why won't the car turn?", happens when a vehicle doesn't turn as quickly as the angle of the front wheels would suggest. Turning the steering wheel further just makes the tires slip more. An understeering vehicle wants to point to the outside of a turn, plowing ahead instead of where the wheels are aimed.

"Oversteer", AKA "loose", or "OH S*&T!", is when the vehicle wants to turn too far, with the back end sliding around and, in extreme cases, trying to pass the front. An oversteering vehicle feels like it's about to spin, and frequently does if the driver isn't skilled enough to "catch" it.

An easy way to remember the difference is that Understeer is when you see what you're about to hit through the windshield, but Oversteer means you see it in the mirrors...

A little theory:

There are a lot of different dynamics that cause under- or oversteer; the front-to-rear weight bias of the car, the presence or absence of anti-sway bar(s), which wheels are doing the work of accelerating the car, and even the size and type of tires.

Most cars come from the factory with a bias towards understeer. That's because it's generally thought that understeer is easier for the average driver to cope with than oversteer, which is probably true. The instinctual reaction for a driver in a sliding car is to lift off the throttle and hit the brakes, which will transfer weight to the front end and increase traction there, helping an understeering car to recover control. Doing the same thing in a car that's oversteering will usually make the situation worse by unloading the rear tires and further reducing their traction.

For this reason, you'll almost never see a factory-stock car with a rear anti-roll bar, but no bar on the front. Without getting into a lot of advanced car dynamics, I'll just say that putting a "swaybar" or anti-roll bar on one end of the car (or replacing an existing one with a stiffer bar) will tend to give the opposite end of the car more traction. Thus, most cars come equipped with a front bar but none in the rear, or if they have both, the front bar will be considerably stiffer. This preserves the tendency to "safely" understeer once the limits of handling are reached.

Great links !!

http://www.rallylights.com/other/stuning.htm#alignment

http://www.turnzero.com/technical_resources.php?resource=vehicle_dynamics_assistant

Levi
10-02-2006, 06:43 PM
I have the ,,,,,,,,,,,,"dammit, why won't the car turn?".

Thanks big D for the info. you ROCK :D :cool: :thumbsup:

jimmysidecarr
10-02-2006, 08:15 PM
Really good stuff everybody!!!

Solid info in an easy to understand format...


Nice job and good find David!!!

Thanks for posting that!!! :thumbsup:

Andy M
10-03-2006, 09:01 AM
I forget which NASCAR driver said this, but here goes... this is SO true!!!

Understeer is when you hit the wall with the FRONT of your car!!! :eek:

Oversteer is when you hit the wall with the BACK of your car!!! :eek:

:rolleyes:

Y2KCOBRA88
10-16-2006, 09:57 PM
"Oversteer", AKA "loose", or "OH S*&T!", is when the vehicle wants to turn too far, with the back end sliding around and, in extreme cases, trying to pass the front. An oversteering vehicle feels like it's about to spin, and frequently does if the driver isn't skilled enough to "catch" it.


The new term for this phenomenon is called "Drifting" :)

03 cobra toy
11-13-2007, 06:34 PM
Ttt


:thumbsup:

97CasperCobra
11-13-2007, 06:47 PM
I had PLENTY of oversteer this past weekend.....:D

Right Stan..... :p

03 cobra toy
11-13-2007, 06:56 PM
I had PLENTY of oversteer this past weekend.....:D

Right Stan..... :p

;).......

Levi
11-13-2007, 08:18 PM
That's Right.... :rotf:

Bartman01
11-13-2007, 09:45 PM
I had a first hand encounter with snap-oversteer on Saturday.