updated 7/25/2007
Tire & Handling Seminar
New Content
The seminar has evolved as I've learned more and figured out
how to better explain some of the more complicated topics. The
viscoelastic nature of rubber and rubber friction generates
a challenge to racers trying to tune a car for maximum grip.
"The car feels like it's up on top of the track instead
of down in the track," is a dreaded driver comment but
actually is a good intuitive description for what's happening
when lateral load transfer timing or damper tuning causes actions
at the contact patches that the tires don't like. I've added
considerable content explaining lateral load transfer timing
and how that timing effects grip and how the car feels to the
driver.
Content Summary
How a Car Turns a Corner: Paul begins each presentation
with an explanation of how a tire generates a lateral force with
a slip angle and how that allows a vehicle to turn a corner with
control at high speed. He returns to this topic later to cover
it in more detail.
Rubber & Rubber Friction: A short history of rubber
covers the discovery and development of this amazing material
and introduces some of its unique characteristics. The way rubber
interacts with a surface to produce friction forces is complex.
You'll learn about rubber's sensitivity to temperature, sliding
speed, surface texture, and vertical loading. Discover the real
reason why there's more grip off-line in the rain.
Rubber Compounding: Learn about rubber choices and
how carbon loading and the vulcanization process modify rubber
characteristics. The complex nature of tires starts with rubber.
Tire Design and Manufacture: Explains how tires can
be flexible but strong while describing some design goals and
structural variables. You'll learn why inflation pressure is
so critically important to tire performance and reliability.
See how a tire generates heat as it rolls.
Tire Behavior: Detail explanation of how a tire produces
lateral force and turns a car. See the importance of camber thrust,
induced drag, aligning torque, the friction circle, and load
sensitivity. Learn the real reason why wide tires produce more
grip.
Balance and Control: Explains understeer and oversteer
and describes how good drivers maintain control at the limit
of adhesion.
Race Tires: Shows how to take tire temperatures and
describes scrubbing, blistering, and graining. Explains how to
find the right inflation pressure. Presents typical data provided
by tire manufacturers to some race teams and discusses whether
this data is actually useful.
Basic Vehicle Dynamics: Presents an understandable
explanation of the physics of a car in a corner, describes lateral
and longitudinal weight transfer, and presents the importance
of roll centers and how to calculate the different components
of lateral weight transfer.
Tuning for Grip and Balance: Explains how to tune a
racecar one level at a time. Learn the difference between spring
rate, wheel rate, and tire rate and read how to choose initial
spring rates, anti-roll bar rates, and roll center locations.
What is geometric stiffness and why is it so important? Learn
the importance of wedge and how both anti-roll bars and dampers
produce wedge effects that help balance a car and generate grip.
Learn how dampers and roll center heights change lateral load
transfer timing and why this is so important. See a sequence
of tuning changes and how those changes affect tire contact patch
forces. Learn why a front anti-roll bar is so useful.
|