Tech Talk: WRC in the dark

WRC Greece 2013 Volkswagen Polo R WRC Andreas Mikkelsen night-time stage
© McKlein Image Database

Although rare in the World Rally Championship, night stages are still a dark art for the crews.

For rally fans little there’s else to make the hairs stand on end like the emerging noise and searching headlights of an approaching car on a night-time stage.

But for the World Rally Championship’s crews, night stages – such as the Kineta test on last weekend’s Acropolis Rally – add a whole new technical dimension.

It might sound crazy, but even with a lack of light the star names will set times comparable with those achieved when the sun is up. So how do they do it?

Pace notes
These are made during the mid-week recce of stages held in daylight, but a second pass of the stage in the dark helps to double check they are still going to make sense after sunset, as WRC leader Sebastien Ogier’s co-driver Julien Ingrassia explains to redbull.com: “For night-time, they must be super-accurate and we might also build in reference points such as a pole or a road sign that will reflect the lights to guide the driver – even sometimes a special tree that you only notice at night. It’s vital the notes are clean of any unnecessary markings as this can lead to misreading or missing a corner.”

WRC Greece 2013 pace notes
The pace notes have to be spot on for night time© McKlein Image Database

Jarmo Lehtinen, who sits alongside Citroen ace Mikko Hirvonen, adds: “Sure the scenery looks different at night, but you deliver the notes in the same time. Maybe you add in some small crests in case there is dust or fog which is when it can be difficult.”

In-car lighting
Cars are fitted with two LED ‘map lights’, just over the co-driver’s shoulder which beam down onto the book of pace notes in his or her lap. They look like a pair of tentacles and bend to enable easy adjustment should a hard landing knock them out of position.

A massive set of spotlights
The lightpod the teams attach to the noses of their cars just before they head off into the dark are incredibly powerful.
Included are six high intensity discharge lamps, with four in the middle and one either side. Each contains a 100-watt bulb – double the amount on your average road car. The drive lens (central pod) point directly forward to illuminate the road ahead with the fog lens (either side) helping to light a wider area of the road.

WRC Rally Sweden Juho Hanninen
Juho Hanninen's lightpod at Rally Sweden 2013© McKlein Image Database

Each pod weighs 7kgs, meaning a significant shift in weight transfer for the car. As M-Sport’s Richard Millener comments: “We counter that with adjustments to the suspension, but they also act as ballast so we can move ballast from elsewhere in the car. Certainly the car’s handling characteristics change and the driver needs to adjust.”

There’s one other obvious technical tweak. “Make sure your lights are at the correct angle. It’s easier to lose time at night than in the day,” says Greece winner Jari-Matti Latvala.

Shadow of doubt
Finally, the night can create the odd illusion. Killian Duffy, co-driver for WRC2 category points leader Abdulaziz Al Kuwari, explains: “We run after the WRC cars so a few rocks have been pulled onto the stage by the time we start – the light beam can hit those rocks and cast shadows across the stage surface giving the false impression there’s an obstacle or a big rut.

WRC Greece 2013 Nasser Al-Attiyah M-Sport Ford night-time stage
Don't get caught out by tricks of the light© McKlein Image Database

“Dust is always the thing you don’t want but even then there are tricks that help, like picking out the marshals’ reflective jackets to tell you which direction the road is going in.”

There’s also the fact of course that some drivers are simply braver than others at night. But never assume it’s that straight forward!