Going from a standard shock to a coilover is a step that every off-roader comes to sooner or later. After the lift kit, the wheels, and the tires are already upgraded, off-roaders looking for the next step will have to take into account their suspension.
Fortunately, Bilstein, one of the foremost manufacturers of shock absorbers in the world, has come out with a coilover that’s dressed to impress – the B8 8112 ZoneControl CR. Sporting Bilstein technology and offering direct-fit replacement, these coilovers are poised to shake up the off-road scene.
The ZoneControl covers late-model Tundras, 4Runners, F-150s, and Wrangler JLs and Gladiators, and comes as a swap-in replacement ready to take these applications to the next level. As one of the newer flagship dampers to come out of Bilstein, we wanted to do a showcase on this product. What follows is a deep dive into this damper and how it changes the off-road game.
Our inquiry into the ZoneControl put us in contact with several key figures at Bilstein. These included Justin Smith, Product Engineering Manager; Shane Casad, Head of Product Management; and Juan Alvarez, Bilstein Technical Center Supervisor. Smith spoke to the engineering side of the ZoneControl, sharing insight into its inner workings.
“Our vision with the B8 8112 ZoneControl CR was to provide a top-of-the-line direct-fit coilover that outperforms anything on the market,” he said. “That goes for both on and off-road driving.”
Part and parcel of this was the development of three independent pistons that fit into the coilover. These pistons control rebound and compression through the damper’s cycling. “Our objective was to develop a fully tunable, position dependent, large-bore coilover damper,” commented Smith. “The idea came from wanting to preserve the size of the main working piston, while decoupling it from the auxiliary damping zones to maximize on and off-road performance. This was ultimately achieved with a three-piston arrangement.”
“Two of the three pistons handle auxiliary compression and rebound,” continued Smith. “They are two-piece designs, and as such they engage with complementary mating parts to form a complete piston. They do this when they reach a predetermined, optimized stroke position.”
Compression is where a damper earns its stripes, and in this department, the ZoneControl sets itself apart. This is thanks to the mating part that conjoins the pistons. “The mating part is secured in a telescoping housing,” explained Smith. “During compression, the part reduces ‘dead length’ and makes the damping more effective. It actually creates the third compression zone once the second zone has collapsed, acting as a sort of safety net should the piston push that far.”
In essence, the ZoneControl’s oil travels through three zones during compression, each one more resilient than the last. What this makes for is a shock absorber that continually gets tougher to match the shock placed on it. In effect, while traveling through whoops and washboards – both of which will cycle the suspension repeatedly – the ZoneControl is prepared to meet these shocks and keep on performing.
Adding to the ZoneControl’s effectiveness are its appending features. One such feature is the external reservoir. “Here, the ZoneControl houses a dividing piston which separates the oil from pressurized nitrogen,” said Smith. “Since the dividing piston is located here, it frees up space in the shock body. It allows for longer damper travel, as well as improving the shock’s thermal performance and ride quality.
Another important feature of the ZoneControl is its threaded spring seat. “This allows for easy spring preload adjustment,” explained Smith. “It sets the vehicle ride height, too. The B8 8112 design is unique in that the upper mount and spring support are integrated as a single component. The rod end is threaded, as opposed to the tube. This allows for longer springs with greater travel, lower stresses, and therefore, improved durability.”
So it’s clear that the B8 8112 ZoneControl CR is well-suited to off-road driving. But how can a customer expect it to perform on-road? Product Engineer Blake Ramuno said, “These dampers handle on-road conditions phenomenally well. A lot of off-road dampers are tuned to excel off-road, while sacrificing off-road comfort, stability, and control. With the 8112s, our engineers designed and tuned with the mindset that people will be driving these vehicles on road daily. So on-road performance was a priority as well.”
Bilstein takes the matter of build quality very seriously. From the high-performance coilovers that go on race trucks and buggies down to the replacement shocks that go on daily drivers, Bilstein ensures that its dampers always get the care and attention they need before they wind up in customers’ hands.
Technical Center Coordinator Juan Alvarez commented on the testing procedures that went into the ZoneControl shocks. “We do our best to handle the product with care, scrutinize all blemishes, and take care of durability and performance issues,” he said. “We perform thorough dyno tests on all B8 8100 series shocks, and correct any damper that is out of tolerance. This ensures that 100 percent of the production run is within tolerance prior to shipment.”
With such stringent procedures, the end result is a coilover with an enviable lifespan. “Our off-road dampers are capable of giving you over 1,000 hard off-road race miles,” said Alvarez. “The B8 8100 series shocks are built with that same level of quality and performance. As long as the dampers aren’t physically compromised, they should average about 100,000 miles of mixed driving before service is needed.”
Rebuildability is also a feature of the ZoneControl shock absorbers, and Bilstein offers rebuilding as a service through its technical department. This involves tearing down a shock absorber to its bits and pieces – hoses, valves, pistons, etc. While a process like this is not something required of the average user, it’s nice to know that it has the capability for restoration, and Bilstein offers this service.
“Rebuilding a B8 8100 series will not be a very common concern for customers, but we recognize this topic is high on the list of concerns for customers buying shocks at this level,” said Shane Casad, Head of Product Management at Bilstein. “We expect customers to have many years of use before needing to rebuild the 8100s. In addition, these are covered under a two-year warranty. Because we follow Bilstein standards for quality, we deliver a high-end product that will not require constant maintenance.”
Fitment options for the B8 8112 ZoneControl CR coilovers cover a good number of popular trucks and SUVs on the market today. “We cover the 2003-20 Toyota 4Runner and Lexus GX460/GX470,” said Casad. “We also cover the 2005-20 Tacoma and 2007-20 Tundra, as well as the 2019-20 Jeep Wrangler JL and JT Gladiator and 2015 and newer Ford F-150. More applications are on the way, including the 2019 and newer Ram 1500, 2014 and newer Ram HD, 2007-18 Jeep Wrangler JK, and 2005 and newer Ford Super Duty.”
For a direct-replacement coilover that promises and delivers on performance, the ZoneControl B8 8112 CR is just what the doctor ordered. Be sure to find out more about this product on Bilstein’s website, and don’t forget to follow them on Facebook, too.