A JK Way Beyond Unlimited
Missouri 4Wheelers Supply, better known as 4WS.COM, is a major distributor of 4x4 parts and is known for its Jeep conversions. After a trip to the SEMA convention in Las Vegas in 2006 and being inspired by how the aftermarket had already embraced the new Jeep Wrangler JK, 4WS.com owner Kevin Wyas decided to get a JK of his own to show off a few of the parts his company offered. The plan was to keep it mild-at least that was the plan.
In 2007, both the plan and engine changed. The JK was taken to the extreme with a new 6.1L SRT-8 Hemi mated to a 5-45RFE automatic transmission. In the process of installing the engine, Kevin designed and started production of ceramic coated headers for the swap, which negated the immediate need for suspension modification, dramatically decreased under-hood temperatures, and increased low end power. This combination resulted in roughly double the horsepower and torque of the stock engine. The guys at 4WS.com were also able to get the Hemi swap tuned and dynoed so that it would be perfect for customers upon pick up. Just having a Hemi was good enough for a while, but more drastic upgrades were still in the future.
To tolerate the power that the 6.1L Hemi put out and the heavy wheeling Kevin wanted to do, the drivetrain was upgraded. Front and rear high-pinion Dana 60s are filled with ARB Air Lockers, Superior Evolution axle shafts, Superior 5.38 ring and pinion gears, and Mile Marker locking hubs, making the axles extremely strong yet still streetable. Attached to the front axle is a steering assist ram from Howe and a custom high-steer setup to help point the big 42s in the right direction and still keep it street legal. Bolted to the pinions are 1350 CV shafts connecting to an Atlas II transfer case with 3.8 low range gears. The 3.8 ratio lets the Jeep crawl with the low end torque the engine and transmission combination turns out and still lets the Jeep get enough speed to haul through the open flats.
The front Dana 60 is kept in place using a Rubicon Express long-arm kit with 12-inch-travel Rock Krawler dual rate coil-over shocks. The front control arms were adjusted out to move the front axle 1 inch forward. In the rear, Kevin adapted the Black Diamond X2 leaf springs to move the rear axle back about 3 inches. Leaf springs were used in the rear to keep the Jeep more stable on and off-road and to handle heavy loads. So far, the leafs have been tested in Moab, Hot Springs, Arkansas, and Seymour, Missouri, with results that are even better than expected. The Jeep is completely stable and predicable and doesn't sag in the rear as much as it used to when loaded down. After moving the axles, the fenders needed to be modified to fit the 42s. Xenon flares were painted and bolted on the front. Rear flares were built on extended AEV corners and the rear fenders were cut out to match the new corners and flares.