Porsche’s Million Dollar Rock Crawler

Porsche’s 959 was conceived as the multi-tool that would dominate Group B rallying, the no-holds-barred series that saw the likes of the Lancia Delta Turbo Integrale, Audi Quattro S1, Mitsubishi Lancer Evo, and Subaru WRX duke it out for top bragging rights on both tarmac and gravel. To qualify, Porsche had to homologate road cars that would be available for purchase by the general public.

Porsche’s Million Dollar Rock Crawler

Porsche’s 959 was conceived as the multi-tool that would dominate Group B rallying, the no-holds-barred series that saw the likes of the Lancia Delta Turbo Integrale, Audi Quattro S1, Mitsubishi Lancer Evo, and Subaru WRX duke it out for top bragging rights on both tarmac and gravel. To qualify, Porsche had to homologate road cars that would be available for purchase by the general public.

There was just one hitch: by the time the car was ready to debut, following a series of high-profile accidents, Group B had been cancelled.

We’ll never know how many titles the 959 could have claimed had Group B lived on, but we do know that the tradition of building Porsches that excelled at speed both on and off road can trace their origins back to Porsche themselves, long before the introduction of its Cayenne and Macan models.

Fast Forward to today, Dakar!

Porsche’s rally legacy continues. New in 2023 from is the 992 Dakar. Paying homage to the rally 911s of old, the Dakar is an impressive bit of kit.

Fast Forward to today, Dakar!

Porsche’s rally legacy continues. New in 2023 from is the 992 Dakar. Paying homage to the rally 911s of old, the Dakar is an impressive bit of kit. The suspension sits 50mm higher than stock, providing superior ground clearance and room for the all-terrain tires.

Dakar has a stainless front chassis guard and rocker panel guards that are integrated to the body shape. All 4 wheels are driven.

Safari Suspension Tech

Suspension Travel

The most obvious thing about Safari cars is raised ride height. Does that mean you can just install longer springs to raise the car and call it good? No, it does not.

If you simply install longer springs you created suspension travel problems that will degrade performance over rugged terrain, as well as potentially create unsafe condition with parts breakage. The shocks also need proper bump stops to protect from damage.

Suspension Travel

The most obvious thing about Safari cars is raised ride height. Does that mean you can just install longer springs to raise the car and call it good? No, it does not.

If you simply install longer springs you created suspension travel problems that will degrade performance over rugged terrain, as well as potentially create unsafe condition with parts breakage. The shocks also need proper bump stops to protect from damage.

Travel

When traversing rugged terrain tires have to stay in contact with the surface or traction, steering and braking are compromised. A tire that is not in contact offers no ability to control the car. Suspension travel is key for keeping tires in contact.

Travel is comprised of compression and droop. Compression travel is self-explanatory and is when the shocks compress in response increased corner load due to bumps or landing. Droop travel is when shocks extend longer than static ride height length.

Having adequate travel in both compression and droop directions is equally important for maintaining tire contact over uneven terrain.

Droop is limited by the fully extended length of the shock. A shock that is fully extended is said to be topped out. A shock that is fully compressed is said to be bottoming out.

How does that relate to raising the car? One could keep the stock shocks and raise the car by simply installing longer springs. However this extends the shock in the static height position, gaining compression travel but at the expense of droop travel.

The reduced droop travel increases the propensity to top out shocks. When this happens the tire loses contact with the surface, along with that tire’s ability to control the car. Topping out aggressively can damage the shock internally.

We address these problem by equipping safari shocks that have more travel and a longer fully extended length.

Bump Stops

Despite efforts to increase suspension travel and ensure proper compression and droop range, pushed hard enough and the suspension will bottom out and top out. Unprotected, this can damage shocks.

We prevent this damage by equipping safari shocks with bump stops.

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 compression travel, increasing the effective spring rate of that corner to provide a smooth landing. Bump stops are like assist springs that work only at the end of the shocks travel.

This is also important to protect a shock that is topping out. We equip bump stops internal to our safari shocks to provide a soft landing when the shock tops out.

In the absence of bump stops, the suspension will bottom out metal-on-metal. Something is going to break sooner rather than later.

Suspension Geometry and Alignment

Raising the suspension properly requires correcting geometry problems that are introduced by the higher ride height. If you simply raise the ride height without corrections you are putting the suspension into droop and the angles of the suspension members change in undesirable ways. You will introduce geometry and alignment problems, as well as potentially create unsafe condition with parts breakage.

Raising the suspension properly requires correcting geometry problems that are introduced by the higher ride height. If you simply raise the ride height without corrections you are putting the suspension into droop and the angles of the suspension members change in undesirable ways. You will introduce geometry and alignment problems, as well as potentially create unsafe condition with parts breakage.

Geometry

When the suspension is simply raised, the angles of all the suspension members change – they angle down aggressively with the wheel end dropping relative to the chassis end. This impacts all suspension members including control arms, tie rods, toe links, and the rear multi-link arms.

This causes the camber, caster and toe curves to be shifted and can make the car a handful to drive. Further the angles on the ball studs become more severe and if the car is raised enough, these ball studs will reach the end of their range of travel. This is unsafe and can cause breakage of the studs or suspension arms. We address these problems with our safari sub-frame spacer kits.

996 and 997 cars have full front and rear suspension sub-frames. The suspension sub-frames provide the inner mounting points for all the suspension arms.

Our safari sub-frame kits fit between the front and rear sub-frames and chassis. The sub-frame is thereby lowered and along with them the suspension arm inner mounting points are similarly lowered. Lowering the inner mounting points reduces the angle of the suspension member and corrects for the angular geometry problems introduced by raising the suspension.

Our safari sub-frame kit thereby shifts the camber, caster and toe curve back towards stock position and allows the car to behave more predictably and similar to a stock ride height cars – despite being raised safari height.

Alignment

When the suspension is raised, static camber moves in the positive direction. That is to say the top of the tires tilt outward at static ride height. This causes increased tire wear, poor traction and reduced grip in turns. While this can be partially compensated using the factory alignment eccentric adjusters, they are limited in adjustment range. For most safari cars with anything more than a modest rise in height, the factory alignments adjusters will max out before a proper static alignment setting can be reached.

We solve this problem by provisioning safari suspensions with adjustable length lower control arms. These LCAs can be lengthened to get the camber back into proper range.

Lift Height, Tire and Wheel Selection

Tire Selection

A wide variety of tire choices are available and range from mild appearing all season tires to rally competition tires and all terrain tires. Tire type and tread pattern have a big impact on appearance, ride quality and handling.

Increasing tire diameter will enhance ground clearance. However bigger tires will be a more challenging fitment and have greater potential for rubbing. Larger diameter tires will also negatively impact acceleration (gearing), braking, and introduce speedometer error.

A square setup is popular and allows full tire rotation, and a shared spare tire (on the roof rack of course). Some consider a square setup visually narrow on the rear of a 996/997, especially turbo and wide body cars. This can be mitigated with rear wheel spacers.

Alternatively a staggered front/rear setup can be used, allowing for wider rear tires to better fill the rear wheel wells.
997 C4 and Turbo cars should use a staggered front/rear setup due to the active front differential. The system is tuned for the front tires to have about 2-3% smaller rolling circumference than the rear tires. Failing to maintain that circumference difference makes the car buck.

We have used 225/55/R18 Front and 225/60/R18 Rear with good results on 997 C4 and turbo cars.

996 C4 and Turbo cars use a different style front differential and do not seem to need the front / rear tire stagger.

For most, tire selection is a compromise between competing objectives. Choose a tire that suits your intended use of the car, creates the visual appearance you want, and is suited to the level of fitment challenges you are prepared to deal with.

Following are some examples:
– 215x65x16 BFG All Terrain on 996
– 225x55x18 Toyo Open Country AT on 997
– 225x60x18 Toyo Open Country AT on 997
– 235x55x17 Falcon Wild Peak AT on 997

Wheel Selection

We’ve seen wheels equipped to 996 and 997 safari cars ranging from 16 inch to 18 inch diameter. For many this is largely a styling decision. Small diameter wheels with tall sidewalls is a classic off road look with a functional benefit by allowing tires to be run at low pressure for increased contact patch off road. Larger diameters create a more modern appearance and in fact the Porsche Dakar uses 19 and 20 inch wheels.

A good approach is to choose your tires first, then get wheels with the correct diameter and width to match the tires.

If you are considering smaller than stock wheel diameter, be sure the wheel you are considering will clear your brake calipers and your rear steering knuckles..

Here are few fitment sizing guidelines:
– 986/996 front and rear 16 inch +
– 987/997 front 16 inch +
– 997 rear 17 inch +

In addition to varying offset and back spacing, be aware that different wheels of a given diameter can have different rim and spoke shape and cross sections. Eg.Some 16 inch aftermarket wheels may not fit even if your car came equipped with 16 wheels from the factory. Some aftermarket wheel manufacturers can provide paper templates the capture the wheel cross-section and can be test fit to the car before purchase.

There are many options and choices for wheel selection. Appearance is the primary driver for most wheel selections. This is very much a matter of personal choice and there are many popular options including stock wheels and rally style wheels. Chose a style that suits the look you want for the car.

Tire Clearance and Positioning

Unless you are planning major surgery, 996 and 997 generation cars are limited in terms of tire diameter and width. The wheel arches have limited clearance. The rears are fairly easy to fit but the fronts are limited due to the need for steering. Tire width, diameter and wheel offset all play into how much room is needed for steering the front wheels.

For larger diameter tires, moving the radiators forward and centering the wheel with caster adjustment are key to fitment.

Radiators can be moved forward by about 1 inch by ovalizing the holes in the radiator mounting brackets, and sliding the radiators as far forward as possible.

Our safari kits include adjustable length caster arms. These provide the ability position the tire fore and aft in the wheel arch. For the front tires this is critical to balancing clearance in front and behind the tire. Both are potential rubbing points when the tire are steered.

We also equip our safari carts with adjustable caster arms for the rear suspension. While tire clearance is not a problem in the rear, these adjustable length arms are important for positioning the rear tires properly in the wheel arch. This is because the raised suspension draws the rear tires forward, and the adjustable caster arms allows them to be re-centered.

Bushings

Suspension bushing selection is critically important functions on off road vehicles. The demands and needs are very different from road cars.

Suspension bushing selection is critically important functions on off road vehicles. The demands and needs are very different from road cars.

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

How stiff should a safari suspension be? That really depends on how the car will be used. Cars that will run off-road over uneven terrain will benefit from softer suspension setups. This provides the compliance needed to allow the tires to follow and stay in contact with the surface.

How stiff should a safari suspension be? That really depends on how the car will be used.Cars that will run off-road over uneven terrain will benefit from softer suspension setups. This provides the compliance needed to allow the tires to follow and stay in contact with the surface.

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.

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.

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. Call us for details at 408-297-2789.