The off-road performance of '86 and newer IFS Toyota trucks leaves a lot to be desired, especially when compared to the earlier-model straight-axle trucks. We prefer to build our trails rigs with straight-axles too, but wondered if we could build a more versatile long-travel IFS setup that would perform well off-road without compromising the ride quality or on-road ride quality.
Total Chaos Fabrication of Corona, CA, has been building desert-racing-inspired IFS systems for over a decade. Their Gen. II Caddy Kit for '86-95 4WD Toyota trucks increases wheel-travel and tire clearance with minimal suspension lift to improve high-speed off-road performance. The Chrom-Moly upper and lower A-arms are extended 3.25" per-side and use 2.5x8" stroke coil-over shocks to dampen 12" of wheel-travel without eliminating four-wheel drive. The setup clears 33" tires (with fiberglass fenders) and is adjustable to achieve anywhere between 2-4" lift. As a secondary benefit, these suspension modifications actually improve the ride quality and the truck should handle better than stock. We ordered a Gen II Caddy Kit from Off-Road Warehouse to install on a '89 4Runner to compare the performance of an IFS overhaul to a straight-axle conversion.
All of the components included in the Total Chaos Gen II Caddy Kit are shown here. To complete the installation we ordered a pair of Sway-A-Way Racerunner 2.5x8" remote reservoir coil-over shocks and two 500x18" Eibach coil-springs. These race-quality coil-over shocks should allow us to really dial-in the spring-rate and shock-valving for a great ride and improved performance on/off-road.
Removing the stock suspension components on any older truck is a wild card. Almost every bolt and bushing in the front-end of our truck was seized in place. After removing the shocks from our `89 4Runner, we still couldn't cycle the stock suspension through its limited range of travel because the factory bushings were so worn-out and dried-up that they were holding the suspension in place.
Replacing the stock torsion bars with coil-overs (retaining 4WD) is one of the most distinguishing features of the Gen II Caddy Kit and provides enthusiasts with a much wider selection of spring-rates. We selected a pair of 3.0 x 18-inch x 500lb coil-spring for our application. 16-inch coil-springs are often used with 8-inch stroke shocks, but most 16-inch springs over 450lb have less than 8 inches of spring compression, which would result in coil-bind. This meant we had to use 18-inch coil-springs in order to get enough spring compression from free length. The 18-inch springs needed to be compressed about 3/4-inch just to fit onto the shock, which meant that there was no more room to adjust the preload/ride-height. Luckily the final ride-height settled to exactly what we were looking for: about 3 inches over stock.
We chose to use 33x10.5-inch BFG Mud Terrain tires, mounted on 15x8-inch forged aluminum wheels from Alcoa with 4.5 inches of backspacing. This is absolutely our favorite tire size for compact IFS pickups. These 10.5-inch wide tires are noticeably lighter than 33x12.5-inch tires. The reduced un-sprung weight improves acceleration, braking and handling without compromising traction off-road.
The Total Chaos coil-over Caddy Kit is just as expensive and almost as time-consuming to install as a properly done straight-axle conversion, but this is not a second-rate upgrade. Our completed 4Runner only sits 3 inches higher and 6.5 inches wider than stock, cycles 12 inches of vertical wheel-travel and clears 33-inch tires.
Our initial impression is that we're going to enjoy the improved ride-quality, handling and all-around performance of this versatile setup. We're planning to install a pair of Deaver leaf-springs in the rear along with a pair of 2.5x12" remote reservoir Sway-A-Way Racerunner shocks and then enjoying the drive on our way to the trail.