Story by Josh Patt, Photos by Brandon Schenk, Alwayz OffRoad
The Rock Cruiser, a vintage look combined with updated technology, for the newest in ProMod class design. Designed to interest the everyman in competitive rockcrawling. The ProMod class has been a staple of the W.E. Rock circuit, a required two-seat design that needs to look like a rig someone could buy.
The philosophy, design, and parts list of the Rock Cruiser is a collaboration of Josh Patt of Rock Tech Racing and Rory Desjardin of RADesigns. Together, they built a machine to tackle the W.E.Rock pro courses around the country. The goal: To compete in every East and West Coast series event in a single season. Seven events crisscrossing the country from Texas to Utah to Oklahoma, back to Colorado, then Tennessee and Washington. Wrapping up at Grand Nationals in New Mexico in September. RTR would be the first to accomplish this feat in the ProMod class. The challenge would take dedication, effort, and even some luck to pull off.
The Rock Cruiser is a complete, round tube chassis designed by RADesigns. It’s a 50” wide, two-seat, front-engine design. It can be built as a comfortable trail chassis or a high-level comp chassis. Josh wanted a chassis that would allow for a radical drive train layout, a mid-engine with a very low set that would include drive train placement with dual offset differentials. Lots of ground clearance while maintaining a low center of gravity. Highly important for the off-camber climbs and big drops that are common on the W.E.Rock pro circuit. The idea was to keep all the weight at the “Beltline” or below. The roof panel was carefully designed to offer the lightest but strongest panel on the car. With dimple dies and heat-treated alloy, it is more than capable of protecting Josh in an aggressive rollover without compromising top weight.
The Rock Cruiser’s drive train has a balance of strength and weight. The engine is a pro-built Toyota 22r series engine with tune-able injection and ignition. The block was even cryo’d! The transmission is a GM TH350 built with extreme rock crawling in mind. The transfer case is a Midnight Metal Works D300 rock box. This case is based on the standard Dana 300 but with major upgrades. It is a complete billet case, machined in-house at Midnight Metalworks. Internals are upgraded as well with 32 spline outputs and a 4.0 low range ratio to help get the Rock Cruiser thru any W.E.Rock course with control. The axles are RuffStuff housings based on the FJ80 land cruiser. They have RCV 300M internals and Detroit lockers with a 5.29 gear ratio built by Victors Offroad. The Hellfire knuckles offer maximum turning angles for the RuffStuff axles. The front and rear axles are offset to the same position in the chassis. This allowed the drive train to sit at an unprecedented height. Josh wanted it as low as physically possible. The skid plate runs the entire belly (front of the engine to the rear of the transfer case) for complete protection. JE Reel drivelines made the parts needed for the drive shafts and carrier bearing to get the power to the axles. Low and light is right!
The suspension setup is different from any standard ProMod buggy design. The Rock Cruiser uses a modified radius arm 3-link both front and rear! There isn’t a need for a sway bar as the bushings have a progressive resistance at the axle mount. The proof is there with being able to use all 14” of travel that the Radflo air shocks offer. This radius arm 3-link suspension is very stable compared to most 4-link suspension designs. It also offers great ground clearance. It’s a win-win.
The interior of the Rock Cruiser is simple. No fluff, just what is needed to pass W.E.Rock tech. Comfort is provided by the FJ40-style low-back Corbeau seats and Corbeau harnesses. There is a RADesigns VX shifter that controls the transmission with confidence. A lightweight, aluminum speedway steering wheel rounds out the rest of the interior.
As mentioned, this chassis can be built as a trail buggy. Keeping that in mind, Josh chose to incorporate rearsteer into the build. Rearsteer is not allowed in the ProMod class at W.E.Rock; that’s reserved for the Unlimited class. However, since Josh likes to tackle the hardest trails with some hardcore wheelers, he didn’t want to be without it. The rearsteer can be locked out in competition.
The decision to use a vintage FJ40 Landcruiser instead of the standard Jeep or Toyota truck was something Josh knew he wanted from the start. “I wanted to keep the Toyota heart/soul with the FJ40 body.” The RADesign chassis allows the FJ40 hood/grill to fit well. “The now Vintage 4x4s are what most of us started rock crawling in; this fits perfect in the ProMod class”. RADesigns did a great job on the aluminum interior and body panels. They brought the Rock Cruiser to life for Josh and the Rock Tech Racing team. It’s a beautiful example of when vintage meets new design for a winning combination. Look for the Rock Cruiser at the next W.E.Rock event.
