Hosting the DTM this weekend is the Norisring, the legendary street circuit in the heart of Nuremberg. As the shortest race track on the DTM calendar at 2.3 kilometers, the circuit enjoys a cult status with drivers and fans and is also known as the “Monaco of Germany” because of its very special flair.
The track runs over public roads that have been cordoned off for the event. Pilots drive past the Frankenstadion stadium, the old stone grandstand and the Dutzendteich pond. It is important that the competitors are totally concentrated over the entire distance, because instead of generous run-off areas they face barriers and at the exit of the Schöller-S many drivers have left their side mirrors on the infamous stone wall. However, the stresses placed on the Ventus Race tires of the exclusive DTM partner Hankook are very low compared to all other DTM circuits.
Public traffic normally rolls over the Nuremberg city circuit and for this reason there is a lot of dirt which can make the track slippery in the first sessions. Over the course of the DTM weekend, the racing line is driven clean, but competitors are advised not to stray from the ideal line otherwise they risk picking up dirt which can lead to off-track excursions.
The track surface of the Norisring is smooth and compact and in the last years has resulted in little wear and tear in the Hankook racing tires. The tarmac, however, has been constantly patched up and now consists of different types of surfaces. “For this reason the drivers must adapt to changing grip levels which can be balanced out with a neutral setup,” explains Thomas Baltes, Hankook’s DTM race engineer.
The need for a neutral setup also applies to the entire track layout of the Norisring, which changes constantly between slow passages and fast straights. Thomas Baltes: “In the tight corners and the hairpins you need a lot of traction to accelerate out of them, on the fast stretches, however, you want as little downforce as possible. That’s why the teams must find a vehicle setup that is balanced.”
Another critical factor are the brakes that are put under constant stress on the narrow street circuit. At the end of the finish straight, the drivers must decelerate for the Grundig-Kehre from 250 to 50 km/h and after exiting this corner they hit the brakes hard again for the S-corner. The very bumpy track makes the car unsettled, which makes it hard for the pilots to find the optimal braking point. “With slightly lower tire pressure the road holding and the traction of the cars improve. But this also increases wear on the Ventus Race tire,” explains Hankook’s DTM race engineer.
Many braking and acceleration manoeuvres put greater stresses on the tread than the structure of the Hankook race tire, which faces neither high kerbs nor high g-forces. Thomas Baltes: “The critical spots on the Norisring are the hairpins after the start and at the Dutzendteich on the opposite side of the track. Those who manage to find the correct braking points and afterwards the optimal traction will be amongst the front-runners.”
