All over South Africa, and especially in Namibia, sand is a vital part of any 4×4 adventure. Once the skills to conquer it have been mastered, sand driving is possibly the most fun you can have in a 4×4. In this chapter, we delve into some of the tips and tricks to keep you on top.
Drop the pressure
Arguably the most important aspect of sand driving is tyre pressure. If you try driving on sand with hard tyres, you’ll soon find yourself struggling. When you reduce pressure by as much as 50% below standard, the footprint of your tyres is lengthened, thus spreading the load over a bigger area. A common misconception is that a softer tyre widens the footprint of the tyre, and although this is not technically true, the bulging sidewalls do offer an added modicum of support if you get bogged down.
Remember that by deflating your tyres, you also increase the likelihood of their popping off the rims, so smooth steering is vital (especially over ruts) if you want to avoid the tedious process of a tyre-change in baking sand.
Another common misconception is that wide tyres improve performance in sand. Remember that increased width equals increased resistance. Very wide tyres cause larger piles of sand to build in front of them, and this will slow you down. As we found at the Battle of the Dunes in Namibia, the guys who struggled had fitted massive, wide tyres.
When in doubt, flat out
Imagine your tyres as little speedboats resting low in the water. The boat needs speed to lift it up onto the surface to gain control and reduce resistance, and it’s the same with your tyres in sand. Driving too slowly in deep sand may cause a pile of it to build up in front of your tyres, increasing resistance and reducing control; if you keep your momentum up, you should be able to ‘float’ on the surface. Change gears as quickly and smoothly as possible at higher revs to reduce momentum loss and to keep in the power band of your engine. Before a hill climb, make sure you are in the right gear so that you don’t have to downshift half-way up.
Straight and smooth
Whether accelerating from a standstill or making turns, keep inputs smooth to reduce wheelspin and resistance. In a manual, you should ideally pull away in second or third gear low range, and ride the clutch a bit longer than usual to reduce wheel spin. That said, most sand should be tackled in high range.
Always take wide turns as opposed to full lock-to-lock U-turns. When pulling away on a flat, make sure that your wheels are pointed straight; and, if you’re in a rut, do not fight to escape the rut − just allow your vehicle to follow it, unless you have to escape. If you are bogging down on a gentler uphill stretch, point your wheels down the slope for a while to build up momentum.
If you do get stuck on a steeper incline which you should have tackled straight-on, keep your wheels straight and reverse out, accelerating gently back the way you went in. This ensures that you do not end up at a precarious angle, and so will avoid a rollover.Always remember to roll to a stop if possible – braking on sand will dig you in, making a smooth pull-away difficult.
Time is of the essence
Driving in the dunes in midday sun is not recommended, for reasons which include sand density and sand blindness. The latter (and more dangerous) symptom is most likely to occur in the rolling Namib dunes or in the white sands of the Cape, where direct sunlight from above causes the contours to disappear, and dunes to appear flat. Countless vehicles have been smashed up because of this phenomenon. Wearing sunglasses does not help, so if you’re in the dunes, be careful to drive either in the mornings or afternoons: take a break at lunch time.
Another time-critical element to sand driving is sand density. Sand is typically denser during colder mornings, when it holds more moisture, which binds the grains together. As the sand becomes hotter during the heat of the day, it becomes looser and more difficult to drive on.
Many years ago, I remember my father going red in the face and introducing me and his brand-new Discovery 3 V8 to a whole new vocabulary when it kept cutting out halfway up every sandy hill. The culprits were traction control and stability control (TC and SC). These systems are designed to reduce wheelspin and yaw movements by applying the brakes to certain wheels and cutting power.
On sand, both of these are precisely the opposite of what you should be doing. If you turn these systems off (hold the offending button in for a good few seconds), you’ll find that your vehicle performs much better in sand. Repeat the process when you turn off the vehicle, as most systems default to Traction Control on. In some vehicles the TC and SC cannot be completely turned off, and there may be some benefit in temporarily removing the traction control fuse. When back on firmer surfaces, get the tyre pressure back to the ideal for the terrain, and revert to TC/SC-on if your vehicle is so equipped.
By Andrew Middleton