Reading magazines, I see a lot of "has too much under/oversteer"... What is that?

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2000 Silver Lightning
#2798 of 4966
Born on date: May 9, 2000
Email: ColinMBurns@hotmail.com



Mods: SnugLid, 20% tint, Airaid, Slush Mats, Pioneer Speakers, Zaino

My Zing Album:
http://www.zing.com/album/?id=4292665015

 

Im pretty sure it is when there is too much "play" or movement in the steering wheel without actually moving. For instance in my 01, i can drive down the street and move the wheel about an inch to the right and to the left without the truck actually moving. Thats what i always thought it was, maybe im wrong.

 

Colin,

I'll take a stab at it....Oversteer is when you enter a curve and turn the steering wheel and the back end wants to swing out from centrifugal forces. Understeer is when you turn the steering wheel in a curve and the car wants to go straight ahead in the initial direction, regardless of steering wheel position.

My old Vette had bunches of oversteer - I could enter a curve and swing the back end a little and hit the gas and it would then want to go straight. If done at the right moment, it was lots of fun.

 

Aforce is generaly correct on this one. At least that what it feels like.



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Andy Whittle
White 2000
#2482 of 4966
Built 4/27/00

My Autocross car

 

Here is another way to say the same thing:

Oversteer: The vehicle turns more than you want it to, the back comes around too quickly.

Understeer: The vehicle wants to keep going straight.

Most vehicles are set up for understeer from the factory, less lawsuits that way...

 

Stock car racers put it simply:

If you hit the wall with your front-end, it's understeering. If you hit it with your rear, it's oversteering.

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Regards,
Gordon

'99 Red Lightning
Johnny Lightning Superchip
Johnny Lighting Ram Air Kit
Century Tonneau
Best 1/4 mi. ET: 13.249 secs

 

I wish our L's had more oversteer, I think thats why the Gen1 lightning was more fun it had more oversteer.

I love to let the rear hang out, and steer with the throttle, with the added power from my chip I can do it somewhat, but still want more oversteer.

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http://donf150.tripod.com/Welcome/id6.html

13.11 @ 104MPH

 

understeer = pushing
oversteer = loose = GOOOOOOOOOOD!


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Paul
'01 Silver L
Moderator: FASTasL at EFI-Street.com

 

Is "Aforce" generally correct, or incorrect? I feel like a junior member right now.

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Jim
Black '00
#1,757 built 3/30/00
Clear corners
JDM street program
JDM 2# blower pulley (ordered)
J.L. Stage II ram-air
90mm MAF
FRPP Oval throttle body
Twin 40 series Flowmasters
3.5" chrome tips

 

gforce

The are some very technicaly based answers to the question. Most people would only be confused and loose intrest if I tried to give one. Your answer was just fine If anyone wants the techie answer, I can point them to a few books on the subject.

Andy

 

Good question. Good topic. gForce had it right.

Loose handling-- (a.k.a. oversteer) occurs during cornering when the car's rear tires lose traction before the front tires. When this happens, the car begins to rotate about its center of gravity, and the back of the car swings out from the intended driving line.

Understeer-- (a.k.a. push, tight handling) occurs during cornering when the car's front tires lose traction before the rear tires. When this happens, the car will not turn as much as intended by the driver's steering input, and will start to drift to the outside of edge the turn.

Check out NLOC topic: http://nloc.org/ubb/Forum2/HTML/001939.html

Spike

 

Good to see I thought of something intelligent.
Would IRS or All-Wheel Drive help this problem? Or is it purely based in the steering mechanism.

Colin

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2000 Silver Lightning
#2798 of 4966
Born on date: May 9, 2000
Email: ColinMBurns@hotmail.com



Mods: SnugLid, 20% tint, Airaid, Slush Mats, Pioneer Speakers, Zaino

My Zing Album:
http://www.zing.com/album/?id=4292665015

 

.

[This message has been edited by DreaminAboutL (edited 06-22-2001).]

 

[This message has been edited by DreaminAboutL (edited 06-22-2001).]

 

This is something I wrote for an autcross message board. Some people may find it interesting. Hope it helps. If you have any questions, feel free to ask.

Andy

* * * * * * * * * * * * * * * * *

Some food for thought and discussion.

1) Most books written around the behavior of true race cars . . . . having
full cages and fully adjustable suspensions. The majority of our cars are
converted street cars or out of date race cars that are no longer are
competitive considering the state of the art courent race cars. Look are the
typical middle of the pack CP car as compared to Pro built by TC Kline BMW
in AP and you will get the idea. If you apply the rules that work on a full
tube frame race car and apply them to your flexible 65 Mustang that handling
of the 65 Mustang may improve, but for a very different reason.

2) A full 50% of this sport is still driver. . . and I am suspect it will
always be. The other 50% is car. I have seen on many ocations a hot shoe get
in the car of the guy yelling "cheater and the hot shoe takes one or two
runs and not only beats the hot head he even beats his own cars times in the
borrowed car. The other example is in A-Mod several drivers/builders have
put there 17-22 year old sons that have been hand trained to drive on the
street. Within a year of getting into the car they are way faster than dad.
Ask the Goodales, Bowlands, Whittles or lots of the families in Nascar and
Indy, the kids are fast. John Thomas in EP, Gary Milligan in A-mod and Peter
Raymond come to mind as "True Drivers". If any of those guys come to your
class, be prepared for large doses of humble pie.

3) Indexes work. . . I often here a driver say that indexes are BS. The
more I look at them, the more I believe in them. I have come to a couple of
conclusions. The high powered cars have a challenge on small slick lots. If
you are slowly getting better on the index you are getting better at
autocross. If you are 75th out of 100 drivers and 6 seconds of the winning
time it's you, the car or both.

4) Computer analysis programs work . . . . www.extremegeez.com makes one
that works. Having the ability to keep a chassis at full g's and balancing
aggressiveness and smoothness is an art that takes a full time driving
instructor or software or both. Women are best to work on aggressiveness
first and then smoothness, most men should work on smoothness first .

5) Attention to detail is hugely important. . . . I have seen any number of
people in formula cars with the tires pointed in every direction and they
wonder why it doesn't work. If you don't know the starting alignment for
your type car ask the fast guys in your type car and copy them. As a rule,
run lots of negative camber, Toe out in the front and toe in in the rear.

6) Most cars handle best then at full cornering you carry the inside tire
that is not powered but only by a little bit. Any more than about ¼" and
you are only putting positive camber into the outside tire of the undriven
tire. Add sway bars to the driven end if you are carrying the tire too
high.

7) If you feel bumps you have problems. . . Tires hate to be surprised and
feeling the bumps is really the transfer of those surprised loads into the
wheel and chassis. Too tight of shocks on the compression setting, running
out of suspension travel or too high of spring rates or heavy wheels tires
and suspension pieces are the most likely cause.

8) Spin out at least one out of six runs. . If you don't spin now and then
either the car is set up with too much push or you are not trying hard
enough.

9) Local autocrosses are just practice for the big time. Treat them as
testing. Try things and see what happens. Testing is everything.

10) Run the current tires for the class if you want to win. Anything else
is just playing. Good fresh tires are worth 2 seconds. If they pick up
gravel off the surface and have a oily look to them on concrete, You have
the right stuff.

11) Springs keep the car off the ground, Shocks are for the trasitions and
Swaybars are for the sweepers.

12) Real brake pads are built for autocross and street pads are for the
street. They realy are different.