The only real concern with propane injection is metering the propane properly so that engine damage does not occur. Just hooking up a hose from the bottle on your gas grill and feeding propane into the engine may give you a heck of a kick in the pants one time, but the engine will certainly over rev or overheat causing damage. The amount of propane needs to be controlled depending on engine parameters, such as boost, throttle position, and rpm. MSD's system not only monitors the engine parameters necessary to ensure proper metering of the extra fuel, but is completely tunable using a laptop computer and the included software depending on the level of performance you wish to achieve. The system also has several built-in safety features that ensure engine damage does not occur. A common misnomer is propane is like "nitrous oxide for a diesel," which is completely untrue. Nitrous oxide instantly boosts cylinder pressures and temperatures shocking the motor's pistons and rods when used. Contrarily, propane is injected gradually as the engine needs it and burns smoothly with the rest of the combustion mixture without the "shock" effect on the pistons and rods that nitrous oxide has. The MSD system is actually controlled through a closed loop ECM that is separate from your truck's computer system, constantly monitoring engine parameters as well as propane pressure and temperature to ensure safe operation. If any parameter is out of range, the system will shut down and propane will not be injected into the engine.
When ordering our kit, we were informed by MSD that while we could install most of the items ourselves, the propane tank must be purchased separately and meet both federal DOT and state and local requirements. they recommended that Southeast Power Systems in Orlando install our tank. The Digital Propane Injection system consists of three main parts: the Electronic Control Unit (ECU), the regulator assembly, and the tank. Even having to assemble the regulator assembly, reroute a heater hose to the regulator, and extend several of the wires in the provided wiring harness, we found it easy to install the components in a little over six hours. Other than drilling mounting holes for the ECU and regulator, nothing more than basic hand tools were needed to accomplish the job. We found the kit to be complete, and the instructions were thorough and concise. Having the tank installed at Southeast Power Systems took the better part of a day; we chose the more complex under-bed installation with a remote fill station at the rear bumper. In-bed installations are less complex and take less time. A concern was how our truck would act when propane injection was added to the modifications we had already performed to our truck. The folks at MSD assured us that propane injection complements other power-adding modifications and is completely "stackable" with computer controllers and intake and exhaust modifications. Power and torque will show the most gain on a stock vehicle and slightly less on a modified vehicle. The end result of adding propane to a modified vehicle will still be greater than the vehicle had before, but will never add up to the sum of the advertised gain of each component.