 The Hummer H3 comes from the...  The Hummer H3 comes from the factory with a 3.5L, inline five-cylinder using a dual overhead cam, variable valve timing, and four valves per cylinder. The only modification that was to be made to the race truck's engine was a different air cleaner. The engine mates to the stock 4L60E four-speed auto tranny. |  The rear bed floorpan was...  The rear bed floorpan was cut open, and a steel sheet well was fabricated to house the fuel cell. |  This modification provides...  This modification provides a large, level surface and allows the cell to be dropped a few inches lower to keep the weight as low as possible. |
 A 44-gallon steel fuel cell...  A 44-gallon steel fuel cell was mounted in the newly fabricated floorpan well. Additional structure and strapping was later added to fully secure the cell and the fuel-line plumbing. |  In stock form, the Hummer...  In stock form, the Hummer has no front support to tie the two framerails together after the bumper has been removed. The build crew added a square tube support to provide mounting and support for the skidplate. |  Here, the body sits on jackstands...  Here, the body sits on jackstands above the framerails. All of the extraneous bracketry and unneeded tabs have been stripped from the rails. The stock rubber body-mount pucks were replaced with 1-inch-longer pucks machined from aluminum round stock. |
 This area of the frame under...  This area of the frame under the front corner of the cab was reinforced, and box material was added here. The front pillar cage legs were later welded to this surface. |  The front end is protected...  The front end is protected with a large 3/8-inch-thick aluminum skidplate built to withstand harsh impact with rocks and other debris. The lower mounting points all use recessed attachment points so that bolt heads do not protrude past the aluminum sheet. |  A 1/4-inch-thick aluminum...  A 1/4-inch-thick aluminum bellypan connects to the trailing edge of the front skidplate. Again, all mounting hardware is recessed to make the surface as smooth as possible. The bellypan helps protect the front driveshaft, transmission, and transfer case areas. |
 Rules allow use of a rear-mounted...  Rules allow use of a rear-mounted tire carrier in this race class. This allows for easier access to the tire, and the tire can serve double duty as an impact point as well should the H3 be hit from behind by another vehicle. Tie-down straps were combined with the lower cradle and center hub mount point to hold the LT315/75R16 Baja TA and stock aluminum wheel in place come race day. |  The front drivetrain was kept...  The front drivetrain was kept essentially stock per the class rules. The factory shock mounts to the lower A-arm using a rubber bushing. For the race truck, the rubber was replaced with a spherical ball insert (arrow) for greater durability and to reduce excessive movement. |  The build crew contacted Fox...  The build crew contacted Fox Racing and had the company build up a mock set of shock bodies to test the range of suspension movement and fabricate mounting points. Front shock travel, inboard on the A-arm, is held stock at about 4.5 to 5 inches. Here, the mock shock was set in place to plan the upper mount hoops. |