PCA Drives This Safari Porsche 911 SC:

Reinforcement

Front Struts

Bent struts are common problem. A hard impact bends the spindle upwards, causing a loss of camber. It is actually the strut body that is typically bent, not the spindle. Strut bodies can be reinforced by welding gussets between the spindle and strut body. This reduces the leverage the spindle has over the body and greatly reduces it’s propensity to bend. A second steering knuckle can be fitted to the strut. This puts the tie rod end in a double shear mount that is much stronger than stock. The double shear not only strengthens the steering knuckle, it also reduces twisting and flex of the steering knuckle by eliminating the bending moment of the stock single shear configuration.

Front Swaybar Mount Reinforcement

Chassis failure around the front swaybar mounts is a common problem.

The stock type through-body swaybar mounts attach to a single layer of sheet metal. It’s prone to flexing, cracking and failure. Reinforce proactively to prevent failure using our doubler plate. This reinforces the area, distributing the load to prevent cracking.

Rear Swaybar Mounts

Factory rear swaybar mounts are simply not up to the task. Originally designed for the lightweight 16mm diameter swaybars equipped on the cars in 1965, these flimsy sheet metal bits fail regularly even in street use. When used with stiffer swaybars or the added load of off-road driving, it’s just a matter of time to failure.

These can be replaced with our sturdy solid swaybar mounts. These are much stronger than factory parts and are pretty much bullet proof.

Rear Torsion Tube

Another common failure point is the area around the rear spring plate mounts. These commonly develop fatigue cracks around the welds that secure the mounting bosses to the chassis. Pre-galvanized cars are further prone to rust in this area. Our doubler plate reinforces this entire area, distributing the load and preventing failure.

Rear Shock Top

The 911 chassis was originally designed to use torsion bar springs. The rear shock tops and the crossmember that holds them where designed to carry the damper loads alone, and not the full weight of the car. Cars converted to a coilover suspension further load this area with the full vehicle weight and should be reinforced. Safari cars that retain torsion bars but will be driven hard are also advise to reinforce this area. Our shock tower reinforcement kit makes this easy.

Suspension Travel and Geometry

Travel

Suspension droop travel is lost when raising the car using factory adjusters. It is important to maintain droop travel. For the suspension to work properly it must not only compress to absorb bumps, it must also droop to maintain tire contact over dips and on the unloaded side of the car when rolling in turns. Further if the dampers (shocks) are topping out harshly they can be damaged. Topping out happens with the shock reaches its mechanical limit of extension.

This is addressed on the front suspension by using our safari struts. These struts have the spindles relocated to the bottom of the strut tube. This has the effect of raising the car without extending the damper. Further the dampers we equip have additional range of travel. This combination provides the added suspension travel and prevents topping out the dampers. On the rear we address this problem by extending the damper range of travel, plus extending its static length.

Geometry

The second problem caused by simply raising the suspension is undesirable geometry changes. This happens because the suspension members become angled such that they are outside of the normal operating range. Operating outside the intended operating range causes static and dynamic toe and camber curves that are poor. At the limit it causes unsafe operation and potential binding and breakage as ball joints and tie rods are forced beyond their design limits for angular deflection. Safari struts with their lowered spindle height corrects the angle of the lower control arms, restoring them back to reasonable position on the camber curve. Static camber is further corrected using our De Cambered Ball Joints.

Safari struts also correct toe curve by moving the tie rod end back to a correct relationship relative to the lower control arm. This keeps the tie rod in the center of it’s angular range of travel at the elevated safari height, avoiding binding and breakage.

Lift Height and Tire Selection

Two Popular Tire Choices

BFG A/T 215/65-16 – These have a diameter of 27 inches, putting the hubs about 1 inch higher than stock. These are the largest size tires that can reasonably be fit to the 911 chassis without major modification. The rear bolts right on, the front require trimming of the lower valence area.

These tires visually provide the big-tire, off road look. They provide the highest height and ground clearance. On the downside the large diameter raises effective gearing, impacting acceleration and torque to the ground. Added rotational inertial and diameter challenge the stock brakes and require a heavier pedal effort. Rally Tires These run on 15″ wheels and have a diameter of 26″, putting the hubs about 1/2″ higher than stock.

Still a large tire visually just dialed back a bit from the BFGs. The smaller diameter provides superior acceleration, braking and handling – relative to the taller tire.

Coilover vs Torsion Bar

Safari cars can continue to use torsion bars and this is most true to the design of the road cars. One issue with torsion bars in a safari application is the increase in suspension travel. Torsion bars twist in operation, that is how they provide their spring force. The amount of twist translates to suspension travel, so a safari car with increased travel will twist the torsion bar more than stock.

If the torsion bar is twisted too far, beyond its yield point, it will be permanently deformed. That’s another way of saying the car will start sagging down. Continue twisting and the bar will break. The maximum angular twist that can be tolerated without deforming is a function of the torsion bar diameter. Thinner bars can twist more than thicker bars. Thin bars also make for a softer suspension.

If you want to build a torsion bar safari car, the safe torsion bar size depends on how much you raise the suspension. But in general we recommend limiting front diameter to 21mm and rear diameter to 28mm. Another approach is to remove the torsion bars completely and convert to coilovers. Coilover setups can provide greater suspension travel than torsion bars. Quality coilover springs do not sag and can’t reach the yield point. This is because the coil travel is self-limiting. The coil will compress fully and coil bind before reaching the yield point. Properly selected coilover spring lengths will not even coil bind because the suspension will be compressing the bump stops before this happens. Our coilover setups are designed to do this properly.

When choosing to run a coilover setup, it is important to reinforce the rear shock towers. This strengthens them to deal with the increased loads presented by the coil springs. Coilover or torsion bar, either can provide a good safari suspension. In both cases quality bump stops of the right length and stiffness need to be equipped to the front and rear dampers. Bump stops provide a transition as the suspension approaches the end of its travel, increasing the effective spring rate of that corner to provide a smooth landing.

In the absence of bump stops, the suspension will bottom out metal-on-metalome, and something will break sooner rather than later.

Suspension Bushings

Firstly: the need to operate in dirt. Spherical bearings and the like are great for road cars but are not the choice for dirt. Rubber bushings are the best choice, they are extremely tolerant of dirty environments. Secondly: the bushings need to survive impact loads and isolate the chassis from those impacts. Again rubber is the clear winner. You may be thinking that rubber gives up precision and control of alignment settings, and reduces driver control. While this is true it is not significant to safari cars, especially when driven in the dirt. The loss of driver precision due to using rubber bushings is noise-level when running tall sidewall tires in dirt. Further, the cornering loads generated are much less then we see on street and track cars – the bushings just don’t deflect as much.

All in rubber is the best choice for most safari builds.

Stiffness

Stating the obvious, tires need to be in contact with the ground to stop, steer, or drive. A stiff suspension over uneven terrain can quickly become a tricycle. Consider that cars without limited slip differentials can actually get stuck if one of the rear wheels is off the ground, or barely touching. This is because open differentials direct the torque to the tire with the least traction. Cars that run only on the street will benefit from a stiffer suspension. Indeed the elevated center of mass in a safari car causes more profound weight transfer than a regular road height car. This is especially noticeable on dive and squat. 911s are known for being steered with the throttle as well as the wheel, this goes in spades on safari cars. Adjustable swaybars can be great way to tune the suspension for the day’s planned outing, street or dirt. Soften the swaybars for off road, stiffen them for street use and enhanced control. They also allow tuning to driver preference and terrain.

For this reason, we recommend adjustable swaybars for all safari builds.

We Correct the Geometry… Properly

Just as lowering a car on coil overs changes its handling and braking behavior, raising its center of gravity presents a corollary set of challenges. In order to optimize your 911’s performance both on and off road, even with a substantial increase in ride height, our engineering team calculated the precise load and response characteristics needed to replicate stock response even with substantial variation from stock parameters.

Elephant Racing Safari Kits are Easily Reversible

Our Safari Suspensions need not be a permanent modification. Run your Safari setup as long as you like, but should you ever decide to revert back to factory ride height, this is very easy to do.

Even if you’ve chosen one of our adjustable-height coilover safari packages, it is very easy to revert back to a factory torsion bar setup at any time and most of your safari components (bushings, drop links, camber plates, etc…) will carry over to enhance a factory ride-height suspension.