Oversteer & Understeer

**kimpOy** · December 20th, 2004 04:51 PM

good point ebbsfolls, i was pertaining my notion to a "SportCAR" or "Race car"
in which its easier to manuever by drivers who are usually know what they are doing..afterall this is in the "Circuit" forum

goodday

**boydapa** · December 20th, 2004 05:07 PM

at last tinanong na rin yan... matagal ko na ksi gusto malaman din. matagal nako nagdadrive pero di ko alam yun mga pinagsasabi ng mge expert drivers lalo na when they test cars for handling performance "pre malakas oversteer o understeer netong otong ito" something like that so i just say " ewan ko basta alam ko lumiliko yun oto i dnt know what u r talking about"

madalas ako manood ng rallye WRC sa tv sa bilis ng mga oto napapansin ko puro oversteer sila pero ang galing nila bumawi o magcounter nun effect

**jim** · December 20th, 2004 05:24 PM

Originally Posted by boydapa

madalas ako manood ng rallye WRC sa tv sa bilis ng mga oto napapansin ko puro oversteer sila pero ang galing nila bumawi o magcounter nun effect

yup sa wrc dapat may oversteer ang mga cars kasi kung hindi lagot sila sa turning lalo na kung kelangan ang mga "power turns" or "power slides". saka ang weight distribution sa wrc cars even. hindi mas mabigat sa harap at hindi mas mabigat sa likod.

**ebbfolls** · December 21st, 2004 02:34 AM

Originally Posted by boydapa

at last tinanong na rin yan... matagal ko na ksi gusto malaman din. matagal nako nagdadrive pero di ko alam yun mga pinagsasabi ng mge expert drivers lalo na when they test cars for handling performance "pre malakas oversteer o understeer netong otong ito" something like that so i just say " ewan ko basta alam ko lumiliko yun oto i dnt know what u r talking about"

Sir,

One important measure of a car's performance is high speed handling, or the ability of a car to maintain its line of direction when turning at speed. For obvious reasons, it is more desirable to drive a car that steers promptly and efficiently, than one that needs a lot of effort to keep in line. Ideally, a car should go wherever you point the steering at the exact time that you want it to. But in the real world design compromises towards ride comfort, and other imperfections, cause some time delay and puts a limitation to the steering capability of a car.

One of these material limitations is the traction of the tires. When cornering, a car is guided through the turn independently by the front and rear axles. The car's directional vector is then directly related to the available traction on either axle. What this means is that if a car is going through a steady turn, losing traction in the front will cause the car to decrease its turning rate, and the driver needs to twist the steering wheel even more. On the other hand, if the car loses traction in the rear, the car will consequently increase its turning rate, thus causing the driver to need to decrease the turning angle of the steering wheel. The first situation is called understeer (i.e., not enough steering input) and the other one is called oversteer (i.e., excessive steering input).

As I've mentioned in another post, designers find understeering safer than oversteer. The reason for this is that the driver is more likely to react instinctively in an emergency situation--such as when a car loses traction. Human instinct dictates that the driver will lift off his/her foot off the gas pedal when the car will start acting strange. Lifting off the gas will then cause the car to decelerate, resulting in weight transfer from the rear tires to the front tires.

Needless to say, transferring weight to the front axle will add more traction to the front tires. Consequently, it will also reduce traction in the rear tires. If the car was oversteering at the time (tail steps out), further reducing traction in the rear will aggravate the situation. However, if the car was understeering at the time (front end plows forward), adding traction to the front tires will obviously help improve traction and steering.

There is however a negative side to front wheel drive (prone to understeering) especially in racing. As pointed out by some of our fellow posters, an oversteering car moves quicker around a corner than an understeering one. Nevertheless, too much of a good thing is also bad. An excessive tendency to oversteer can also eventually make it more difficult for the driver to guide the car around the corner efficiently. As such, having a neutral steering tendency (equal oversteer and understeer tendencies) is best. For this reason, designers always try to achieve a 50-50 weight distribution, especially in a racing car.

**jojo_mouth2** · December 28th, 2004 08:51 PM

nice one ebbfols...

**imprezawrxsti** · January 10th, 2005 02:49 AM

Originally Posted by kimpOy

advantage ang RWD,

imagine this ano ang mas bilis at mas may control
Pulling a cariton or Pushing it?

This is kind of late but.... Front wheel drive has more control in real life, that's why that's one of the reason mas maraming front wheel drive, sa mud and snow RWD is hopeless. Sa tight cornering, AWD is the best, it's like a guided missile, turo ka lang ng turo. Once you got into AWD the're's no turning back. Imagine yourself in 110/km hr in a tight corner.....sarap.

**imprezawrxsti** · January 10th, 2005 03:22 AM

Originally Posted by boydapa

at last tinanong na rin yan... matagal ko na ksi gusto malaman din. matagal nako nagdadrive pero di ko alam yun mga pinagsasabi ng mge expert drivers lalo na when they test cars for handling performance "pre malakas oversteer o understeer netong otong ito" something like that so i just say " ewan ko basta alam ko lumiliko yun oto i dnt know what u r talking about"

madalas ako manood ng rallye WRC sa tv sa bilis ng mga oto napapansin ko puro oversteer sila pero ang galing nila bumawi o magcounter nun effect

Yong sa WRC ang mga sasakyan ay AWD, sa pag-counter ng effect ng high speed there is a driver's talent of course but the most part i think is yong high technology ng AWD system ng rally cars, like transfering to front wheel drive/ rear wheel or part with the most traction in a seconds. Sa STI there's a DCCD sa evo yata ay YAW control.You can do it manually, or leave to the computer to figure it out.

**wrecker** · January 13th, 2005 06:15 PM

this thread is very informative :cool:

**nugundam93** · January 20th, 2005 09:04 AM

Originally Posted by imprezawrxsti

This is kind of late but.... Front wheel drive has more control in real life, that's why that's one of the reason mas maraming front wheel drive, sa mud and snow RWD is hopeless. Sa tight cornering, AWD is the best, it's like a guided missile, turo ka lang ng turo. Once you got into AWD the're's no turning back. Imagine yourself in 110/km hr in a tight corner.....sarap.

has anyone seen a video of vicki butler henderson (dunno if it was from top gear or another show) where she compares FF, FR, and AWD sedans? one of the tests there was putting a pengiun plushie at the end of a rather tight s-curve. the AWD car was able to avoid the pengiun with some understeer, the FR car was clearly able to avoid it, while the FF car plain ran over the pengiun.

pero sabagay, she knows what she's doing (countersteer, etc.) so mejo napapalabo din yung idealness of the test. and she did acknowledge na some FF cars perform better than others, etc...

road cars, awd or ff talaga.

race cars, fr, or with 50/50, or awd. :D

**Marc MD** · February 9th, 2005 06:09 PM

buti nlng FF ang Corolla ko... pero i experienced an oversteer sa dulo ng Macapagal highway.. yun T section ng Macapagal at Buendia.. i was zooming from Macapagal turning right to Buendia.. when suddenly i oversteered and made an almost 360 na ikot... my whole flashbacked in my mind and all i can see is a revolving buendia street before me... i tried to counter the tailspin but walang nangyari... my engine went off as i stopped and my whole body was shaking i didnt even see how fast i was.. fortunately no one was hurt and i dint bump onto anything.. but it sure taught me what oversteering was...