Our Race Hummer started its life as a H1 Hummer fitted with the standard 6.5Litre diesel big block chev engine. We removed the engine and fitted a 509 cubic inch (8.5 Litre), 750 Horsepower fire breathing, gasoline (petrol) fueled race engine.
We stripped the H1 Hummer bare, removed all the armour plating, bullet proof windows, roof and interior and and fitted an internal roll cage for safety. Proformance staff also fitted safety harness points to allow the fitment of Klippan 6 Point Race Harnesses.

During testing of one of our Hummers with the 509 Big Block engine, we managed to destroy 5 Automatic Transmissions in less than 10 hours. Proformance tried every sort of billet and custom manufactured part in the 4l85E transmissions and even tried a 2000HP rated Turbo 400 in a Hummer, but the 509 kept killing each and every Automatic we threw in after around 60-90 minutes each.

Proformance staff used our CNC Machines to created a custom, billet aluminium transfer case adapter to couple the original Hummer Transfer Case to a brand new sequential 6 Speed Holinger Racing gearbox.
Proformance then removed another DEAD 4 Speed Automatic Transmission and installed a Holinger RD6 Sequential Shift 6 Speed Racing Transmission. The Holinger Gearbox is the same one used by Both Holden and Ford in the V8 Supercar Series in Australia and is more than capable of handling the Big Block engine. As the Four speed automatics traditionally had a very week top gear, the Holinger 6 speed provided Proformance Hummers with another Three (3) gears. This doubled the acceleration of our Race Hummer!
The H1 Hummer was then Soda Blasted and the panels prepared for painting.
Our 750HP Race Hummer Engine is a 509 Big Block Chev. We use a Dart Race Prepared Block, Chrome Moly Forged Crankshaft, H-Beam Rods, Forged Mahle Motorsport Racing Pistons, Aluminium Heads with 2.30" Intake Valves, Solid Roller Race Camshaft, Jesel Shaft Mount Rockers, Huge 700lb Crane Polished/Plated Race Springs and a MSD Billet Aluminium Nascar Ignition system with Dual Ignition Pickups.
The 509 Cubic Inch Race Engine was installed a few times to ensure everything lines up perfectly. Because the Engine in a H1 Military Hummer is MID MOUNTED, Many modifications were necessary to allow this huge engine to fit in the engine bay. The body was lifted 76mm (3 Inches), the braking system was relocated and a custom made billet aluminium air filter was manufactured to fit under the windscreen frame.
The body and cage was painted in Two Pack HELLA Yellow and fitted to the chassis providing a glass smooth finish that resembles a show car or Hot Rod.
Additional coolers were fitted to cool the engine and the Holinger Sequential 6 Speed Transmission. Custom Billet Aluminium Body Mounts were manufactured to raise the body 76mm. The heavy steel bumpers, tow bar and other steel components were removed and remanufactured from light weight aluminium.

The roof was prepared with additional bracing and brackets to tie the roof to the internal roll cage to prevent roof damage during extreme driving.

Roofs and doors were then painted with Two Pack Enamel, cut with 1200 grit wet paper and then polished to a mirror finish prior to having decals applied.
After thousands of hours of hard work, our H1 racing Hummer was released to the public at the 2007 Perth 4WD and Adventure show at McCallum Park in Perth Western Australia.