Monday, 15 April 2013

Silverstone Musings

Six hours racing at Silverstone, then, and a dominant victory for Audi, just as at Sebring.

But things are rarely as simple as that, and I spent a long time after the race discussing the events of a race that, in the end, covered just three laps more than the six hour WEC race last August.

But the most significant aspect of the weekend, to my mind, was the fact that the works Audis pitted after just 22 laps of the race. Thereafter, the longest Audi stint was 25 laps, but this was only achieved when laps completed under “Full Course Yellow” conditions (and rain) slowed the pace dramatically - generally, the standard Audi stint was 24 laps.

This compares to last years race, in which the Audi R18 could manage 28 or 29 laps on its 58 litres of diesel. Indeed, a comparison of the amount of fuel used by the winning Audi last year and this years winner shows that McNish, Duval and Kristensen used 22% more fuel this year than Tréluyer, Fässler and Lotterer did to win last year's race.

When Allan McNish was asked about this during the race, he explained: “More downforce equals more drag equals more fuel,” which sounds reasonable enough, given the new aero package on this years R18 e-tron quattro, but even so, the amount of extra fuel used is still somewhat astonishing (and came as a surprise even to Toyota).

An analysis of the fastest 50 laps achieved by the two Audis reveals that the average lap time improved by nearly two seconds, compared to last year, an indication that the 2013 car is an improvement over last years model. This contrasts with Sebring, where the 2012 car actually beat the new car in a straight fight.

However, the fact that a front driveshaft failed on the number 1 Audi, and it was still able to finish a few yards behind the winner, indicates that the hybrid system, while improved (we are told) from last year, still does not contribute very much to the performance of the V6 turbodiesel internal combustion engine. This surely must be the aspect that Audi has to improve if it is to stand any chance of continuing its winning ways once the 2013 revision of the Toyota TS030 Hybrid appears at Spa.

And what any of this means for the low-downforce requirements of the 24-hour race at Le Mans is another matter altogether.

1 comment:

  1. Paul,
    Always good to get your initial analysis, and with hindsight I think there is a clear train of Audi thought behind it. Recalling the end of 2012 Toyota were handing out a bit of beating and clearly something had to change. Toyota showed higher pace and consumption plus tricks with aero, Audi have responded by levelling that playing field, 'if you can't beat them...'
    At Silverstone we saw the new arch/wing extensions, and presumably increased front downforce to balance that out. That is a fundamental difference to cranking everything up from a low downforce slippery Le Mans bred car. Dr Ullrich commented on expected wet running during the race, which in real terms never materialised, although Toyota fell for the shower bluff of trying the 'slick-sponges', but given the expectation and conditions of the previous two days Audi may have gone for a wetter set-up than optimal. As an aside this may in part have accounted for the observed and much discussed porpoising of the top contenders.
    Further to setup, the actual weather encountered, not in terms of rain, but high winds. It was quite brutal as we cycled the track, we saw the engine cover of the G-Drive car cleared from the racing line to the track extremities at T2/3 at one point purely by the wind at track level ! The Silverstone layout is largely twisty from West to East and on-throttle from Maggots to Stowe (East - West) into Sunday's prevailing wind. I'm no expert, but using a cycling perspective I suspect you gain little benefit through the twisty stuff, but when you head into the wind it seems much harder work... Did this impact upon the consumption too ? The porpoising was evident on the Audi's through Becketts, and worryingly so from the Toyotas at higher speeds on Hangar, given the once disturbed Davidson flight last year, and acknowledge aero brilliance of the Toyota this needs to be kept an eye on from a safety perspective.
    Finally, Hybrid systems.. Has the kinetic flywheel system peaked ? We're aware that from the off-season, as documented by Mike Fuller of, and 'the on/off bulge' that Audi were keen to introduce the Air Pressured Hybrid system, but were subsequently warned off... Was this an acknowledgement that flywheel development / deployment was limited either by development or regulation ?? I guess time will tell. I suspect the #2 car ran within itself matching the performance of its #1 slightly lame (through hybrid drive failure) brother, and only breaking cover in that seemingly magical chase-down in the final 30 minutes.
    It made for a great spectacle, and a truely fascinating race with close finishes in all categories, each of which deserve their own analysis. This in much contrast to the tyres and DRS fest going on elsewhere in the feeder series ! Long may endurance racing reign !