With extensive experience in motorsport (leading roles in Sauber in F1 and in rallies with VW), Willy Rampf, VW technical consultant for the Pikes Peak project, received a call from the German car maker to lead the return to Pikes Peak 31 years after the victory escaped due to a mechanical failure a few corners before the getting to the peak. We talked with him about the most important aspects of the I.D. R before the moment of his coronation.
This is an unusual project, that of being able to create a racing car from scratch and in record time. Was that what made you leave your retirement on stand-by and come running to Colorado?
I undoubtedly packed my bags shortly after I received the invitation in early September last year. It is a special challenge to start a race at 2800 meters above sea level and finish at 4300 meters. A lot goes during these 1400 meters (every 100 meters going up you lose 1% of oxygen). We had to develop very special aerodynamics because at the finish line there is 35% less downforce than at the start-line and that explains this huge rear wing, the biggest I've ever used in my long career in motorsport. It is true that, unlike a car with a combustion engine, the engine does not lose performance because, but there are losses in brake cooling and it is hard on the driver.
Considering that between the start of project and the official presentation of the I.D. R only 9 months went by where did you do the altitude tests, considering that in Wolfsburg (note: VW´s headquarters city) is a flat region?
Yes, the highest mountain there must be less than 20 meters high. We had to work hard on simulators and we had a great help from our Porsche colleagues who run a very competent test centre in Weissach (note: and also considerable Porsche LMP1 know-how...). We got a very precise idea of the car´s handling and the difference to what we see in reality is very low. There are always some areas that we cannot work in the wind tunnel and there the simulation is instrumental.
I.D. R has to be fully recharged in 20 minutes due to the Pikes Peak regulation. Taking into account that charging is done at 90 kWh, this means that the battery should have some 40 kWh capacity. Are we far from reality? (note: VW did not disclose the battery capacity)
I'm not telling you the precise battery capacity (but it's enough to get to the top of the mountain). We have two batteries due to packaging reasons (one behind the driver and one on to his right, whereas his seat is on the left). The most important thing to note is that although they use lithium-ion chemistry (similar to that of mass-produced electric cars) they are quite different because they have high power as main priority, not high density that is necessary to assure the longest possible driving range which is the main issue on series production electric cars. The I.D. R has to be very fast on a short distance, an electric road car has to have a reasonable performance level but in the longest possible distance.
There are two motors, one close to each axle, with similar power, with a total output of 680 ps/650 Nm which is less than many internal combustion engine cars here at Pikes Peak. That means four-wheel drive ... but do you also play with variable torque distribution?
We have two independent propulsion centres and we just have to ensure that there is compatibility in the rotating speeds of the two motors. Thus, we vary the torque distribution on both axles but in a very small percentage. I admit that having torque vectoring on the wheels on the same axle would be an advantage (even with a little extra weight because more sensors and more complex electronics are needed), but we had no time for that. The same can be said about the possibility of having 4 motors instead of 2 (one per wheel and not one per axle). And we could have gone for more power but that would also mean more weight. The car had the best compromise in that respect.
And the rear wing is fixed by a technical option ... or also due to a time limitation for the car´s development?
I do not deny that it would have taken more time to develop a rear wing to generate a DRS effect (variable aerodynamic support like F1), but I think the benefits would be small as there is no very long enough straight at Pikes Peak.