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TECHNICAL REVIEW SERIES PART 3

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POST XMAS TRIP

POST XMAS TRIP

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Approach Angle

As highlighted in Part 1 in Issue #485 of the Club Magazine, the lack of approach angle is a significant issue for the Subaru Outback and the XV, as the bottom of the front bumper bar simply digs in. However, by installing an off-road bull bar from SubaXtreme, the improved approach angle becomes sufficient to enable one to keep up with full size 4WDs that are lifted and with bull bars. The photo below is a XV going down steep sand dunes at Portland, which it would not have been able to without the improved approach angle.

Similar to most 4WDs, legally modified Subarus are still limited in their off-road capabilities. However, in most circumstances they are no less capable than similarly modified full size 4WDs.

When fitted with suitable tyre and wheels, Subarus are highly capable. Here are some photos of what suitably “shoed” Subarus are capable of. Modern Subarus have forward facing air intakes that are located just above the headlights. The air intake for older models are typically situated behind the headlights. In both cases, they are prone to water ingestion into the air filter box should the water level be too high. The breather for the rear differential is located just at the top of the differential.

With the rear differential breather re-routed, air filter box waterproofed, and the air intake relocated, Subarus are reasonably capable in crossing deep water.

Courtesy of Andrew Westerland

The standard ground clearance of 200mm220mm on stock Subarus is reasonably respectable. However, with most 4WDs using off-road tracks being lifted with large tyres, it is not uncommon for obstacles to require greater than 200mm ground clearance. A vehicle with increased ground clearance will also benefit from improved approach, ramp-over, and departure angles.

A rear differential locker forces both rear wheels to rotate at the same speed, eliminating the possibility of one of the rear wheels “spinning up” due to loss of traction. These two modifications together enable a Subaru to tackle terrain that would otherwise be considered a challenge for highly modified full size 4WDs.

Keeping up with highly modified full size 4WDs. This photo was taken from the XV in the above picture, which was following behind this modified GU Nissan Patrol. A suitably modified Subaru, even the modern CVT equipped models, can be highly capable off-road vehicles when suitably modified.

While there are some real limitations to a Subaru’s off-road capabilities, much of the “inadequacy” are perceived rather than real. The key obstacles that present serious difficulties for Subarus are • Very deep ruts, because there is a limit to the size of tyres Subarus can use (legally). • Very deep water crossings, because

Subarus are light vehicles thus is more at risk of floating or being pushed downstream by fast flowing currents. • Very high steps, as they require large diameter tyres and very good approach angles to get over. • Terrain with significant cross-axle obstacles.

However, modern Subarus equipped with

Traction Control / X-Mode have the advantage of “virtual lockers”. Adding a mechanical rear locker results in an effectively twin-differential-locked vehicle.

This significantly overcomes the loss of traction issue associated with wheel lifts, due to the lack of suspension travel / articulation limitation of Subaru platforms.

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