It’s been a while, but work on our Project Unfair is underway again. After my last project, I vowed not to ever use drag-racing parts for fuel delivery again. I was able to get that system to work most of the time, but eventually heat would cause cavitation, vapor-lock, and failure.
Instead, I worked with Carl Casanova at Vaporworx on our fuel tank. Unfair requires a wider range of fuel delivery than most cars since we’re expecting decent mileage while cruising, and 1200+ horsepower when running full-boogie for a quarter-mile pass or running the standing mile. As Carl calculated that means fuel needs range from 4 gallons per hour to 130 gallons per hour!
VaporWorx provides late-model GM fuel pump solutions to hot-rodders. These fuel modules, as GM refers to them, solve many problems. They are controllable by PWM (pulse-width modulation) and so can be slowed and sped up as the engine need changes. They also provide reservoirs to reduce cavitation, and can be hooked up to Walbro venturi pumps to literally be able to pump fuel to the last cupful in the tank.
Most of VaporWorx setups use a 5th gen Camaro pump, but that’s not quite up to the task, so we stepped up to a CTS-V pump. And that wasn’t enough, so we’re running two! VaporWorx has made some tweaks to their programming to support dual modules, along with setting a ramp-up method to support our crazy need to run 18 pounds of boost on race gas. Boost works against the fuel injectors: as the pressure increases, the injectors have to overcome it, so higher fuel rail pressure is needed. The VaporWorx controller takes all this into account. It’s an awesome solution to a difficult problem.
I built a fully-custom aluminum tank with dual pump module rings, fuel level sending unit boss, fill port to use a 67-68 style gas cap, vent, and drain ports. I’ll also be using our unique fuel tank vent/baffle along with a non-vented cap to control fuel slosh and gas fume emanation.