Data from the Porsche 911 RSR transferred in milliseconds
The Porsche works team sends two 911 RSR to tackle the opening round of the FIA World Endurance Championship WEC at Spa-Francorchamps on 1 May. The successful team of the Stuttgart sports car manufacturer faces unique conditions in Belgium’s Ardennes region.
High or low downforce: only marginal differences
Every year we face the same question concerning the special features of the racetrack: high or low downforce? In terms of lap times, it actually doesn’t make a difference, describes Alexander Stehlig, Head of Operations WEC. The Porsche RSR, which contests the GTE-Pro category of the FIA WEC, offers several means to adjust the amount of downforce. “In contrast to the LMP1 prototype vehicles of the past few years, we don’t have a special aero kit for Le Mans in the GTE-Pro class to reduce drag,” says Stehlig.
In previous years, the LMP teams often used the WEC race in Belgium as a test run for the 24 Hours of Le Mans. At Spa-Francorchamps, we always opt for a lot of downforce, even if the long straights make a low-drag configuration seem appealing. This allows us to be faster in sections of the racetrack such as Pouhon, while in other places we lose a bit of time. It balances out in the end, says Stehlig. A setup for high downforce also makes it easier for the drivers in fast corners, on crests and in dips.
Those who want to make a phone call in a mountain village...
One 7.004-kilometre lap of Spa-Francorchamps means an elevation change of about 100 metres. Cutting-edge technologies are used to maintain radio contact with the driver and keep the ongoing flow of telemetry stable at all times. The two-way radio communication between the gantry and the cockpit is ensured by digital radios supplied by the British provider MRTC.
The broad bandwidth of the digital communication technology ensures that an exclusive channel is available for each vehicle and the race control officials. The technology that is installed in the Porsche 911 RSR weighs just a few hundred grams and is mounted where the passenger seat is in the road car. The team members at the mission control area and in the pits usually communicate with their full-speed heroes in the cockpit via sturdy headsets.
The technology decides autonomously
When it comes to exchanging data between the vehicle and the pits, Porsche relies on extensive mobile phone technology. The system checks at high frequency whether 3G, 4G, or soon even 5G data connection is the strongest. For example, from the La Source hairpin near the village of Francorchamps via satellite to Great Britain or Australia to the data centre of the mobile communications provider Vodafone, and back through orbit to the pit gantry on the Belgian circuit.
“Although the data travel long distances, all values are available within milliseconds, For emergencies, there’s a backup solution, for instance in case the data connections via the three strongest local mobile networks don’t work due to possible overloading, explains Torsten Eichler, Porsche 911 RSR system engineer for the FIA WEC. We have a receiver module at the pits for such situations. If the data can’t be sent in the normal way, the cars send parcels directly to our on-site server should it be necessary. The connections between the technicians’ laptops and the data server are secured, among other means, via a VPN tunnel – unauthorised access is not possible. It’s not enough for a really precise analysis of the setup or the drivers’ different racing lines. We only get the necessary data if we read it from the laptop at the vehicle during or after a session. We’re talking about ten megabytes of data per driven lap, says the experienced engineer. Reading the telemetry data The data packets, which are sent from the 911 RSR to the computer systems at the control centre during practice or the race, are usually only a few megabytes. “It’s enough to ensure the safe operation of the cars at all times and to make the most important tactical decisions,” explains Stehlig. It’s not enough for a really precise analysis of the setup or the drivers’ different racing lines. We only get the necessary data if we read it from the laptop at the vehicle during or after a session. We’re talking about ten megabytes of data per driven lap, says the experienced engineer.
Apr 26, 2021 at 17:46