i dont get hwat causes understeer and why it only/ mostly happens on FWD cars. does it happen when you turn and inut throuttle so the wheel spins, therefore not getting grip and slidding foward? thanks

 

Well, understeer happens for many different reasons. On FWD cars, generally it happens because the the car doesn't have 50/50 weight distribution AND when you go around a turn since the front wheels are the pulling wheels and they are turned while giving throttle the front tires lose traction causing the car to continue in a linear motion....straight.

You can induce understeer also on any car by pumping the front tires up more than the rears. The front tires will grip a little leass than the rears causing the car to slide more through the turns. Also, if your car has a staggered wheel setup (rear wheels are wider than the front) this will cause understeer.
Hope this helps.

 

sidewalls also cause understeer. Picture your tire sitting there with loads of sidewall. When you turn your wheel to the right, the rubber on the pavement won't move right away. The tire is too flexible and allows this to occure. the more sidewall you have, the more you'll have to turn your steering wheel to the right just to get the "contact patch" to turn right. Low profile tires have less sidewall, therefor you'll have to turn your steering wheel less to the right to get the contact patch to turn. When you turn the steering wheel and it moves alot more than the contact patch, it's called "understeer". This is because as you turn the wheel, the car will still want to go straight, or "understeer" if that makes any sense whats-so-ever

 

thanks, so basically i was right. thanks alot

 

having no ***, causes understeer..

 

this is pure BS

 

fix ur tire pressure and throw in some left foot braking and you wont have any understeer

 

What causes understeer.. Well, basically, your outside front just gets overloaded, and breaks traction sooner then the rear.. Every production car built understeers at the limit, they are designed to, its "safer" and the average Joe can control it...

Now, to get rid of oversteer, a nice phat rear swaybar will help, because it puts more transitional weight onto the outside rear, basically doubling the spring rate of the rear suspension under corning, reducing the traciton of the outside rear tire, helping it to break traction faster then the front..

You can also put stiffer rear springs on.. most FWD cars have about a 150lb rear spring and 250lb front spring stock.. I run a 800lb front and 1000lb rear, the heavier rear springs help overload the rear tires, making them break traction at the same time as the front, to give the car a neutral feeling.. Mind you, these are RACECAR spring rates, and are WAY to stiff for the street...

 

How stiff is 'too stiff'? For instance, using your description for your neutral feeling, you'd swap out a 300lb rear spring and have roughly the same ratio as your racecar.

What does this do to the feeling of the car? ~what do you mean by neutral? (I'm a total newbie)

When you say brake traction at the same time, is that implying the car is sliding sideways on all 4 wheels ?

Thanks.




[Modified by kotetu, 6:43 AM 1/10/2003]

 

This guy know his stuff. If your wrong he'll let you know, and don't argue with him.

 

rear swaybar=***...

 

get a SH, tein, spoon strut bars, sticky tires and eliminate understeer.

 

huh? how the **** do sticky tires eliminate understeer?

and please do not copy Corey's setup, he came back to the pits complaining the car needed more rotation after being full lock sideways into turn one at Lowes (very fast and scary corner), three times in a row

 

I beg to differ. it's a form (or factor) of understeer. Look at a picture showing understeer, the front end wants to swing wider than the rear end. with the larger sidewall, it causes more flex between the contact patch and the rim its self, a form of understeer (IE> The rim is trying to make a tighter turn arc than is the contact patch its self, reducing the traction in the front region). Since the rear wheels dont' deal with this on a FWD the same as the fronts have to, it enhances the affect of the total understeer. Hence the reason when you go to a larger diameter rim on a FWD or increase the tire preasure, the front won't have this problem as bad and it helps reduce the overall understeer

>>Understeer
<Back to Last Page> <Full Glossary>
Related Terms
• push
• tight
• loose
• oversteer
Definition: This is when the front tires are not getting enough grip on the racetrack. This causes the car to want to continue straight ahead when the driver turns the wheel.

 

You are right. The more sidewall you have..the more likely it will collapse underpressure. That's also why lower profile tires are used on performance cars.

That dude up top may know what he is talking about.....but there are other parts to the spectrum.

And yes, stickier tires will help decrease understeer.

 

this is prolly a stupid question but, what is sidewall? is it like the side of you tire?

 

you dumb ignorant cocksucka, sticky tires ain't the only thing i listed. learn how to read.

you act like he's the only/first one with that setup. copy? wtf you talkin bout you ***** rider.

 

yeap, the area that runs past your rim (IE> connects the tread section to the rim its self). and just a side note, only the top section of sidewall actually keeps your tires off the ground. it's much like the spokes on a bike. when you sit on the bike, the bottom of the "rim" doesn't really do anything, and if you've ever looked at how they are made you'd know. the top section actually suspends the "axle" and that's what holds your car off of the ground

 

LOL ...

Getting an SH may not be the easiest way to decrease understeer, you know. But yes, SH has less understeer, mainly due to ATTS system and a smaller front anti-roll bar.

TEIN suspension will not decrease understeer. The Tein SS has 8kg/mm front, 4 kg/mm rear and the Type-HA has 12 kg/mm front and 8 kg/mm rear. These are approximately the same ratio of spring rates as OE. Therefore, even though you're increasing the wheel rate, you're increasing them proportionally front and rear.

Spoon strut bars won't contribute much to understeer/oversteer. It just eliminates chassis flex during hard cornering. Spoon strut bars don't use triangulation and are not part of a roll cage, and look better than they perform.

Sticky tires won't reduce understeer because you increase the traction capacity both front and rear. Unless of course you mean putting stickier tires in the front and using *** tires in the rear.

I'd say the most cost-effective way to reduce understeer is to use a larger diameter anti-roll bar as Corey said.

As for the argument about sidewall ... conceptually that might make *some* sense, but it has no place in real world applications. The reason FF race cars use lower profile tires is so they can fit larger rotors in the larger wheels. The R-compound tires of today don't flex much at all and aren't subject to that reasoning.

~Nam

 

Another way to help lessen understeer is to learn how to take corners and bends properly.(not meaning to sound like a *****)The way you drive affects your ability to keep traction and or lack of under your control.

 

Dont you mean understeer??? I thought adding a stiffer rear sway bar on the Prelude helps to get rid of the cars natural tendancy to understeer?? Not Oversteer. Can you please clarify??

I got a ST sway bar set that seems to stiffen up the rear more than the front. So what steering aspect is being changed?

 

first of all take a f-ing joke .............. don't read to far into things

second of all everything you listed made very little sense

SH?
tein?
what's so special about Spoon strut bars?
sticky tires even with what little I can decipher from that setup will not help loosen the car up

learn to explain things legibly instead of wasting space with useless info and maybe next time you will have an arguement against me

and no, sticky tires willl not reduce understeer, at the limit if the car is gonna push it will push wether on Hoosiers or Continentals


[Modified by urbanlegend21, 11:36 AM 1/11/2003]

 

No way dude, I am sorry.. Why do you think touring cars run big wheels, well, to either fit over the brakes, or the class makes them do so, the same reason why they ALL have rear spoilers, so people on the street will go out and buy rear spoilers and big wheels, so they think their car is a "touring" car now.. Most of racing is marketing, and doesn't make sence on a racetrack..

Now, if your tire is deflecting (rim is turning more degress then the tire) what do you do? well, TURN MORE! A tire w/ more sidewall does not have the responsiveness of a shorter sidewall tire, that is true, but it will grip just as much, if not more because it will form to the track better.. Also, you are forgetting how it responds to the rear tire.. the rear on a properly setup car is going to have just as much "weight" on it as the front, that is why roadracers put stiff springs in the rear.. so that rear tire is going to deflect as well on a large sidewall tire, and swing out the rear end.

this is correct

 

get rid of the ST front bar, put stock back on..

 

basically, but once you have the back end swinging out, your oversteer drifting, which is really slow!