So you have a 4×4 and plan on competing in a rally or getting to grips with some serious off-roading. Or perhaps you’re dreaming of overland adventures with wild camping under the stars? In this feature the experts from euro4x4parts Mecazine explain why it is so important to know your vehicle. Whatever your plans, it is important to know your 4×4 and have it set-up properly so that the vehicle is adapted to your requirements and the conditions it will encounter out in the field and therefore reduce the risks of breakdown or breakage.
Different 4x4s and different set-ups can be intended for very varied uses. From week-end green-laning to overlanding, rally-raid and extreme offroading , etc. It is important to know your 4×4, it’s specifications and limits. You will then be ready to choose the right parts and accessories for your set-up.
If you have a 4×4 and intend to enjoy green-laning, all-terrain tires and firmer suspension are a must. If your 4×4 is going to be used for long, overland journeys and perhaps wild camping, you will need: all-terrain tires, suspension lift, camping accessories and navigation equipment. For rally-raid or competition use, in addition to a standard off-roadset-up, it may require complete vehicle modification such as reinforced body, roll bar, etc in order to meet safety standards.
Finally, for extreme offroading, you will be looking at oversized all-terrain tires, so-called “extreme” suspension, hydraulic steering, a winch, roll bar, etc …From this, it becomes obvious that a basic 4×4 with stock set-up remains like any other vehicle and may not behave as expected as you push it over its basic limits.
So here are some of the basics you need to know when choosing your 4×4 and set-up so that together they match you plans and requirements.
One of the fundamental notions that determine just what your 4×4 is capable of is described in terms of “angles”.
1 – Approach angle
The approach angle, also known as the attack angle, refers to the angle between the point of contact with the ground and the lowest element of bodywork at the front of the 4×4. This is the angle at which an obstacle may be approached before the vehicle will touch it.
2 – Departure angle
The departure angle similarly refers to the angle between the point of contact with the ground and the lowest element of bodywork at the rear of your 4×4. This is the angle at which you can leave an obstacle.
3 – Ramp angle
The ramp angle, also known as the breakover angle, refers to the angle between the 2 points of contact with the ground and the lowest element under the middle of the 4×4. This angle determines the ability to clear an obstacle such as a ridge. This is angle is what makes the difference between long-wheelbase (LWB) & short-wheelbase (SWB) designs. The latter have a better ramp angle and therefore a better clearance ability.
Ground clearance is the height measured between the ground and the lowest element of the vehicle. For a 4×4 with a solid axle design, this is more often than not the differential. This is a key value to take into account when heading over rocks or when both wheels run through deep tracks.
These angles as well as the ground clearance can be modified & improved to increase the offroad performance of your 4×4 whether you are on an expedition or competing. As we mentioned above, you can change the suspension and tyres of your 4×4, for these kind of modifications.
In terms of improving the ability of your 4×4 one of the first steps is usually to install a suspension lift kit.
The immediate effect is improved attack, departure and breakthrough angles.