specifications

Not all Rally Fighters are built the same.  The specs below are for RF0143.

ENGINE AND TRANSMISSION

The “stock” Rally Fighters from the Local Motors micro-factory came furnished with a 6.2 L LS3 E-Rod package from General Motors.  This engine produced 430hp and 424 ft-lb of torque.  There was even a supercharged 640hp version.  As it was a complete package with the GM ECU from the factory this made the Rally Fighter 50 State emissions legal.  The engine was typically paired with a TH400 3 speed transmission or a 4L85E 4 speed transmission mated to a Ford 9 inch rear end with 31 spline alloy axles, an Eaton Truetrac limited slip differential and 4.11 gear ratio.

Due to an unforeseen engine and transmission failure at 11,000 miles, RF0143 has had a complete upgrade.  The best guess as to why the engine failed is because the oil pan on the LS3 was too shallow – so if the Rally Fighter had spent a lot of time in the air then it would likely have suffered oil starvation.

Given the opportunity to perform a “forced upgrade” I consulted with race engine builder Eric Herbert of Herbert Performance Co. in Reno, NV.  Eric has been building race engines for over twenty years and is a factory GM Performance dealer, so he was definitely the right person to source and build a Chevy V8 with genuine OEM components. 

Rather than re-work the original LS3 Eric suggested we “go big” and install a hybrid engine with a LS7 bottom end and ported LS3 heads.  This would give us more displacement with the same engine footprint.  The engine was furnished with forged internals, chromoly pushrods and a Lingenfelter cam.  To prevent another oil starvation issue Eric installed an ARE LS7 dry sump kit, which (mercifully) meant that it was possible to keep the stock air-conditioning system.  As part of the refresh all new ancillary parts were installed as well.   The end result is an engine putting out 540 hp and 560 ft-lb of torque on the engine dyno. The beauty of this engine build is that it makes nearly 500 ft-lb of torque at 2,500 rpms, where it will be usable.

Installing the motor would require some fabrication and knowledge of off-road platforms.  Fortunately Samco Fabrication stepped up to the plate and offered to tackle the project.  Sam and his team have have been building and driving winning desert race vehicles for over 12 years.  Their repertoire of customers include Baja 1000 legends Hall Racing USA as well as running factory Hummers for General Motors.  The good news is that they ran similar dry sump systems on their desert race engines, so they knew how to optimally configure the engine bay to fit all of the components.

Driving along the freeway with a 3 speed transmission was terrible, so the failed TH400 transmission was upgraded to a 4L85-E with upgraded 5 pinion planetary gears and a new Chevy Performance Automatic Transmission Controller that plugs directly into the E-Rod package ECU to keep things “OEM”.  To manage the increased torque of the engine a new torque converter was customized to the engine builder’s specs and installed.

WHEELS AND TIRES

Originally the Rally Fighter came with Method MR301 wheels.  These were not beadlock wheels, which meant that they were lighter, but there was always the possibility of the tires de-beading when aired down for driving off road.

Rather than install traditional beadlocks, which tend to be heavier, RF0143 has been furnished with ICON Rebound Pros, which utilize ICON’s Innerlock Technology, which secures the bead of the tire using bolts that thread directly through the shoulder of the wheel.

The original tires were Goodyear Wrangler Duratrac.  And by original, the date code on the tires meant they had been installed for over 10 years, so they needed to be replaced before they fell apart.  To ensure drivability on the road and capability while romping around in off road, RF0143 was equipped with BF Goodrich A/T KO2s, which are known for their durability and prowess in the desert.

The custom tire carrier allows for a full-size spare to be carried without taking up the precious cargo space on the inside.

BRAKES

The brakes were sourced from different OEM platforms to fit the vehicle. The front brakes are from a 2004-2009 Ford F150. The rear brakes are from a 1979-1985 Cadillac Eldorado. This makes getting new pads and hardware as simple as taking a trip to the local auto parts store.