Speed king
VW’S PURE ELECTRIC ID.R RACE CAR
Back in June, Volkswagen made electric vehicle (EV) history with a run around the legendary Nurburgring Nordschleife circuit in its ID.R racer. The fully electric ID.R raced through the 20.8km Green Hell in a time of 6:05.336 minutes and at an average speed of 204.96kmh, using just 24.7kWh of energy.
Driven by Romain Dumas, this meant the ID.R was not only significantly faster than a GT3 sports car, but also consumed only a quarter of the energy.
Now, VW has released some fascinating facts and figures about the run – some specifically about the ID.R, others that relate to the unique demands of such fast driving.
During the ID.R’s lap, Dumas was subjected to centrifugal forces equating to about three and a half times his own body weight while cornering. The measuring instruments on board the 500kW ID.R recorded up to 3.49g.
‘‘Two major differences between the ID.R and the sports car I drive in 24-hour races are the considerably higher cornering speeds and the shorter braking distances,’’ says Dumas.
The top value of 3.49g was recorded during the left-right combination in the Kallenhard section of the circuit. The most dramatic deceleration came when braking into the Aremberg corner, where the carbon-fibre brakes on the ID.R achieved a negative acceleration of 2.7g.
Your head weighs 20kg
The high centrifugal forces are a challenge for the driver, and particularly the neck muscles. When stationary, the neck must support roughly 5kg of head and about 1500g of helmet.
The top value of 3.49g in the Kallenhard section of the Nordschleife temporarily increased that weight to more than 20kg for Dumas.
He prepares for this kind of physical exertion with fitness and strength training. ‘‘To simulate that kind of situation, I have fitted an old helmet with weights. I use it to train my neck muscles in my fitness corner in the basement of my house,’’ says Dumas.
The ID.R hit top speed on its record-breaking lap in the Fuchsrohre section, a dip at the end of a longer downhill section.
Here, the sensors recorded 273kmh.
Dumas came through the famous Caracciola- Karussell at 83kmh, the lowest speed recorded on his record
DRS activated over 20 times
To make the most of the energy stored in the lithium-ion batteries on board the ID.R, Dumas had a manually-activated Drag Reduction System (DRS) at his disposal, similar to the one used in Formula 1.
‘‘At the push of a button I can adjust an element of the rear wing to significantly reduce drag,’’ Dumas explains.
While he was able to call on the maximum downforce generated by the two-metre plus rear wing, DRS reduced the aerodynamic drag of the ID.R in 23 spots on the circuit – such as when accelerating and on straights.
This way, the two electric motors on the front and rear axles were able to make particularly efficient use of the energy stored in the batteries. During the record-breaking lap, DRS was open for a total of 88.82 seconds, 24.3 per cent of the driving time. The longest section with DRS activated was the 3km Dottinger Hohe straight at the end of the lap.
The fact that Dumas was able to hit a high final velocity on this last section of the track was the result of an energy recovery strategy developed by Volkswagen Motorsport specifically for the Nordschleife.
The ID.R generated 9.2 per cent of the energy required for the record lap through brake energy regeneration.
This figure fluctuated over the course of the lap, depending on the circuit profile. The maximum value was achieved just before entering Dottinger Hohe. By the start of the straight, the ID.R had regenerated exactly 9.87 per cent of the energy consumed to that point.
Glycerin generator
To generate the energy required to charge the batteries, Volkswagen Motorsport turned to an innovative method.
For all of the ID.R’s record attempts, a conventional looking generator has produced the primary energy required. Its power unit does not run on diesel fuel, as is common, but on glycerin.
This liquid – in chemical terms a sugar alcohol, obtained as a byproduct of, for example, the production of bio-diesel – burns virtually without any harmful emissions or residues.
Glycerin itself is non-toxic and is even approved as additive E422 in the food and cosmetics industries.