ICON: A Little Jab
Tire temperature is a crucial parameter for the performance of any tire. A topic also reported on in the first issue of Christophorus 70 years ago.
The tires are the only connection between the surface of the road and the vehicle, whether series model or race car. Their grip properties play a key role in roadholding in everyday use and consistently fast laps on the racecourse. The Porsche racing engineers take this to heart in the early 1950s. Even back then, the key parameters for exploiting the full potential of the tires are air pressure and, more importantly, the temperature of the road surface – a topic also reported on in the first issue of Christophorus 70 years ago.
To this day, racing tires still receive a small jab whenever the driver makes a pit stop. The tire experts insert a fine needle probe just a few millimeters deep into the rubber. While this approach has changed very little over the decades, the method has been enhanced: once the key area of focus, the temperature at the center of the tread is now accompanied by that of the inside and outside.
The measurement results at these three points provide important insight: Is tire capacity being used efficiently? Are the tires overtaxed or could they withstand even more? Ideally, tire potential is used evenly across the full width of the contact surface.
Slick tires like it hot, with a temperature range of 90 to 110 degrees Celsius offering the best grip. In professional racing, the tires are preheated to around 80 degrees using electric blankets or heat chambers, which allows them to reach their optimal temperature range on the course faster.
While the measuring instruments were little more than antiquated fever thermometers in the 1950s, modern digital devices are now faster and more precise. What hasn’t changed is the analogue way in which the measurement values are recorded: they’re written down by hand on sheets of paper and passed on to the racing engineers.
Boxster 25 years
10.9 – 10.1 l/100 km
247 – 230 g/km
10.8 – 9.6 l/100 km
246 – 219 g/km