It is a piece of cake to imagine that designing a tire for the family-run
MPV is well at hand for modern engineering.
However, when it comes to high performance tires designed to make sports
cars handle, the expectations move considerably.
In addition to precision, grip, braking performance, and handling, the need
to be fully worthy of the performance car is important. The tire also needs
to deliver high levels of grip and braking performance for public roads and
also withstand high temperatures at the track without exhibiting any
weakness. A tall order indeed!
So, where does a tire manufacturer start? To find out, Car spent some time
with the engineers from Continental regarding the development of the new
ContiSportContact5P, one of the new breeds in performance tires.
The first step for the tire engineers involved specifying the requirements of
the tire – steering precision, balance, lateral grip, control, performance, and
change after tire warm up.
As with many tires, the P5s are original equipment on specific vehicles.
Therefore, the automakers provide the tire men with a long list of
requirements that the tire needs to meet. Continental was given
access to confidential information such as weight, suspension set-up,
etc. that was fed into a computer to be processed before the tire was
developed for prototype testing.
An important aspect of a tire’s performance involves its slip angle (the
angle between the direction that the tire contact patch is pointing and
the direction it is actually traveling). If there is a large slip angle at
the rear as compared to the front, the vehicle overseers (bits hard
in a corner). On the other hand, if the slip angle is large at the front
compared to the rear, the vehicle understeers (drifts to the outside of
a corner). A normal slip angle is between one and three degrees. However,
as cornering loads become greater when driving a sports car, the rate of
slip angle becomes non-linier (increases significantly). And the vehicle’s
handling becomes unpredictable at the limit and the steering becomes
The goal for performance tires is to optimize the tread pattern, compound
stiffness and maximize the tire’s contact patch. Under lateral acceleration
(which sports cars are known for), the size and the shape of the tire’s contact
patch changes, which affects the tire’s grip. If the tire compound is soft, it
locks in with the road surface, but it can deform under hard cornering.
What does this mean? Well, a high performance tire can have its tread designed
in blocks that helps the tire to distort less. Additionally, different compounds
are incorporated into the tire thus enabling the edge of the tread to have different
characteristics from the center tread of the tire.
Regarding Continental’s high performance tire, the engineers call the tire compound
“black chili’ because it is a cunning chemical recipe designed to provide just the
right balance of grip and temperature qualities that specify how the tire will perform
as it heats up. What is the one thing that is missing in regard to modern tires?
It is rubber, as all tires are now made of synthetic materials.
So making high performance tires is actually a good part science but also ‘black’
Have an auto question or comment? You can email it to me at
Kbusch3@verizon.net. Kyle Busch is the author of “Drive the Best
for the Price…” www.DriveTheBestBook.com.