over-steer/under-steer chart

[GMR911]

Hi, does anyone have the chart that shows the changes made to susp components/tires and how those changes affect over-steer/under-steer. Thanks Jerry

[Eagledriver]

You don't need a chart. If you increase the grip at the rear you'll increase understeer and if you increase grip at the front you'll increase oversteer. If you increase roll stiffness in front you'll increase understeer, if you increase roll stiffness in the rear you'll increase oversteer.

-Andy

[obrut]

I have one I put together from various sources (mainly Steve Weiner at Rennsport and Tyson Schmidt).

PM me your email address and I'll shoot it over.

Its a word doc and I can't seem to post it here.

[Won]

First result up on Google:

Front Springs Stiffer: Front roll resistance increases, increasing understeer or reducing oversteer
Rear Springs Stiffer: Rear roll resistance increases, increasing oversteer or reducing understeer

Front Stabilizers Stiffer: Front roll resistance increases, increasing understeer or decreasing oversteer. However, cars w/ independant suspensions may experience a reduction in camber change, allowing better tire contact patch compliance w/ the road surface. This reduces the total amount of understeer, but car is still in understeer mode.
Rear Stabilizers Stiffer: Rear roll resistance increases, increasing oversteer or decreasing understeer. However, cars w/ independant suspensions may experience a reduction in camber change, allowing better tire contact patch compliance w/ the road surface. This reduces the total amount of oversteer, but car is still in oversteer mode.

Front Dampers (Bump & Rebound rates not independant) Stiffer: Front roll resistance increases, increasing understeer or reducing oversteer
Rear Dampers (Bump & Rebound rates not independant) Stiffer: Rear roll resistance increases, increasing oversteer or reducing understeer
Suspensions with independant adjustability of Bump and Rebound Rates:
Increase rebound and bump rates: Ride harshness increases. Turn-in is more crisp.
Increase rebound rates only: On bumps, tires may leave track surface.
Increase bump rates only: Body roll resisted; outside tire loaded too quickly; car won't stabilize into a turn.
Decrease rebound and bump rates: Ride harshness decreases; car may float over bumps.
Decrease rebound rates only: On bumps, tires follow track surface more effectively; car may continue to oscillate after bumps.
Decrease bump rates only: Body rolls quickly; car is slower to respond to turn-in

Front Tire Pressure Lower: Lower tire pressure reduces the contact patch (contact patch shifted more to the edges), making the tire slightly less efficient. Less traction on the steering tires increases understeer.
Rear Tire Pressure Lower: Less traction on the rear tires may lead to the rear end sliding out, resulting in oversteer.

Weight Distribution: Tires only have 100% grip capacity available. A larger amount of traction is needed if there is more mass. When turning, moment arms must be taken into consideration since they basically add more forces for the tire to overcome. This is why 50/50 weight distribution is ideal. Under 50/50 distribution, the moment arms can be neglected and only the tire's maximum grip will be the issue.
Forward Weight Distribution: Moment arm loads the front tires which decreases grip capacity and increases understeer.
Rearward Weight Distribution: Moment arm loads rear tires which decreases grip capacity and increases oversteer.

http://www.superhonda.com/forum/f27/suspension-tuning-204-adjusting-oversteer-understeer-207942/