Suzuki Samurai Suspension Upgrade - Project Sami SupremePosted in How To on April 1, 2008
Picking up where we left off with the first part of our Sami Supreme project, a master plan was formulated to begin the radical transformation. Next, a toyota five-speed transmission was installed along with a dual-T-case setup, and it was time to address change in tire size. The 35-inch Baja Claws that were on the Sami from its initial buildup December 2003 issue) were great tires, as were the Eaton steel beadlock wheels they were mounted on, but there were many situations on the trail where a larger tire would have helped. The steel beadlock wheels are extremely tough wheels, but not the lightest, especially when you're trying to turn them with a 65hp engine, so a decision was made to upgrade both the wheels and tires to something taller and lighter.
After a bit of "wheelin' and dealin'," the Baja claws and Eatons were sold and replaced with an almost new set of 37x17 Goodyear MT/Rs. The MT/R is a great tire, suitable for a wide range of terrain, and is fairly lightweight compared to similar tires. The only problem was that the new 37-inch tires would not clear the firewall, so the front axle would have to be pushed forward a bit. This in turn would require modification to the front fenders, relocating the steering box, and the entire front suspension would have to be completely redesigned. A benefit of moving the axle forward would be a longer wheelbase. The current 87-inch wheelbase was simply too short to conquer extreme angles and hillclimbs, so a stretch in that department would really help.
With a bit of research and inquiries into popular wheelbase lengths, it was finally determined that 100-110 inches is optimal for a rig riding on 37-inch tires. Averaging this figure, it was decided that the new wheelbase should be 105 inches. With the wheelbase determined, it was time to figure out what to do with the suspension. While the Jeep Wrangler YJ leaf springs that had been on the sami for the past four years offered a lot of flex and stability, the setup was getting a little worn-out, and with all of the modifications to the wheelbase and chassis, it only seemed natural to step up to a link setup. There are a lot of different link setups out there to choose from, so the next crucial decision would be finding a setup that would work on the Sami while providing the ultimate in flex and drivability.
Looking further into linked-suspension setups and becoming thoroughly confused, a call was made to All-Pro Off-Road. Considering cost, clearance, usage, and everything else involved with the project, All-Pro recommended a three-link setup with a Panhard bar and air shocks. As luck would have it, the company had just developed its Taco' Supreme system, which is a weld-on front three-link (with Panhard bar) setup that could possibly be adapted to the samurai. Designed to retrofit a solid axle under the Toyota Tacoma, the Taco' Supreme kit includes all necessary frame and axle brackets as well as shock towers and heavy-duty adjustable links outfitted with large heim joints and extra-tough Johnny Joints.
With three-link kit in hand, it was evident that with some slight modifications, the kit would work on the ront of the Samurai and even push the front axle forward just the right amount to allow firewall clearance for the new 37-inch tires. The nice thing about using the All-Pro kit is that all of the engineering was already done by professionals, ensuring correct suspension geometry. Once the front suspension was set up, the rear could be duplicated using the same components to also provide correct geometry.
Starting up front, the all-Pro suspension was mocked-up and tacked into place. The front fenders were removed, and a new front bumper was fabricated to extend the framerails, providing a new mounting location for the steering box and winch. To complete the front suspension, a new, heavy-duty custom axlehousing was ordered from Diamond axles, making the setup extra-bulletproof. Finally, some tube fenders and a narrowed tube grille were fabricated to finish up the front, and it was time to tackle the rest of the rig.
Moving toward the back, the rear axle was repositioned to make the wheelbase 105 inches, and the bed was removed with a sawzall. Next, the rear framerails were narrowed to rovide clearance for the rear shocksand tires, and a new bumper was fabricated to tie it all together. A 12-gallon jaz fuel cell was chosen to replace the stock gas tank and integrated into the new rear end. Beneath the rear of the rig, a three-link setup (with Panhard bar) was designed, fabricated, and assembled to duplicate the same dimensions and geometry as the front all-Pro kit. Just like the front, a Diamond axle housing was used to finish up the rear-suspension setup.
After many hours of tube bending, notching, fitting, and welding, the rear of the sami supreme began to take shape with a rear extension added to the existing rollcage along with some new, integrated rock sliders. With the front and rear suspension tacked into place, everything was cycled and measured, using jacks and a forklift before permanently welding all frame, shock, and axle brackets into place.
Once the suspension and cage work received the final welds and gussets, it was time to address the details. Coast Driveline & gear built a custom set of driveshafts using standard, easily replaceable components. A new transmission tunnel and seat mount was fabbed up and tied into the frame. Next, a large bellypan skidplate was designed and constructed to protect the new drivetrain.
With everything buttoned up, the sami supreme was ready for some brief testing in the parking lot before turning it loose in its natural habitat. All of the steel was cleaned up and given a fresh coat of Krylon just hours before its debut at the 45th annual tierra Del sol Desert safari. Only a few short months after the project began, the sami supreme was tackling some serious terrain with ease at tds and wowing the crowds as it performed flawlessly the entire weekend. The story doesn't end here, however, as the next part of our sami supreme project will feature more trail testing and an upgrade in the horsepower department.