Part of the appeal of the Ultimate Adventure is that you never know what is coming next. It might be rockcrawling or sand dunes or mud or miles of twisty backroads. Building a suspension that can handle these various terrains is no small feat. Fortunately the brilliant minds at Fox are always looking for ways to build a better mousetrap. On the Ford Raptor they designed an internal bypass shock, and now they have devised externally adjustable dual-stage compression (DSC) adjusters.
DSC adjusters are optional on a wide range of Fox products, or you can upgrade your existing Fox remote reservoir shocks. We used them on 2 1⁄2-inch-diameter, 14-inch-travel Fox Performance Series coilovers on the Dynatrac Pro Rock 80 under the front of our Tug-Truck in conjunction with the three-link and track-bar suspension Pacific Fabrication designed and built for us. Out back, a smooth-boy Fox shock was used in conjunction with BDS leaf springs.
While Fox didn’t invent adjustable shocks, Fox has taken them to the next level by accounting for shock piston velocity. The low-speed compression adjustment has 10 settings that can be dialed up on the pavement to reduce sway and then dialed back in the dirt to maximize traction. The high-speed compression has 12 adjustments that allow you to improve the ride quality and then crank them up fast when off-road to prevent the suspension from bottoming out. Perfect for taking our Tug-Truck on a thousand-mile cross-country adventure!
We used 2 1⁄2-inch-diameter Performance Series coilover shocks on the front of Tug-Truck. The larger shock body provides increased fluid volume and a larger piston for better control of our heavy truck, while not being so large that the shocks are difficult to package.
The two dials on the top of the shock reservoir are clearly marked. The gold dial has 12 settings for high-speed compression, and the blue knob has 10 settings for low-speed compression. Turning in the “plus” direction (counterclockwise) results in firmer compression valving.
Pacific Fabrication built shock towers to position the coilover shocks to allow for 6 inches of uptravel and 8 inches of droop through the shock travel. This is a good compromise between low lift height and enough uptravel to soak up bumps at speed.
We cycled the suspension under Tug-Truck to determine bumpstop placement and measure for limit straps. These steps are critical to ensure that your coilover shocks are not the limiting factors for either compression or full droop, as this can damage the shocks.
In addition to coilover and bypass shocks, Fox also manufacturers smooth body shocks with DSCs that work in conjunction with leaf springs or coils. We matched up their 21⁄2-inch-diameter Performance Series remote reservoir shocks with our BDS springs to retain the payload of our truck while allowing for a plush ride when the bed is empty.
The high-speed compression (HSC) adjuster knob offers 12 settings and mainly affects compression damping during medium to fast suspension movements, such as steep jump faces, harsh flat landings, and aggressive washboard roads.
The low-speed compression (LSC) adjuster knob offers 10 settings and primarily affects compression damping during slow suspension movements, such as G-outs or smooth jump landings. It also affects wheel traction and the harshness or plushness of the vehicle’s ride.
The Fox coilovers worked great on the combination of pavement miles and varied 4-wheeling that we encountered at the Ultimate Adventure. We raised the HSC and lowered the LSC on the street, then dialed back the HSC when we got to the trailhead.