|
|
Propane Injection For Dodge Ram Cummins Turbo Diesel - Propane - It's Not Just For Grilling AnymoreInstalling MSD's Digital Propane Injection On Your Cummins-Powered Truck From the April, 2006 issue of Mopar Muscle By Dave Young Photography by Dave Young
|
|
We are all aware that propane is a safe and convenient fuel for heating homes, drying clothes, and cooking steaks on the grill, but did you know that propane can also be used to safely add power, torque, and range to your Cummins-powered Dodge truck? That's right, diesel engines actually respond very well to propane injection as a power adder and the Cummins is no exception. The Cummins engine is powerful in stock form, but who can leave anything stock? With so much aftermarket power-adding equipment available, we just couldn't leave well enough alone. It started with wanting to add just enough power to our '01 dualie so the transmission wouldn't downshift when towing our car trailer up inclines, but like most gearheads once we started exploring how much power these engines can make, we couldn't stop. After adding an Edge computer, wastegate controller, and free-flowing exhaust, and burning up our torque converter, requiring it to be replaced with a beefier unit, we still wanted more. Our research led us to MSD ignition's web site where we learned about their Digital Propane Injection. Propane has been used as an automotive fuel for quite some time in gasoline engines and though slightly less efficient than gasoline is an extremely clean burning fuel. A diesel engine operates somewhat differently than a gasoline engine taking in the maximum amount of air possible during each intake stroke. Engine speed is then determined by varying the amount of diesel fuel injected into the cylinders. The result is that there is nearly always extra oxygen in the cylinders that has not been used up in the combustion process. When propane is injected into the cylinders through the intake system it bonds with the additional oxygen and combusts with the rest of the fuel resulting in substantial gains in power and torque. The same power can be attained by adding more diesel fuel, which is the premise used by computer programmers or "chips," but the extra amount of diesel necessary to make the same power as propane is usually not feasible without making costly fuel system modifications. Diesel fuel also burns at a slightly higher temperature than propane, so exhaust temperature can limit the amount of power that can be attained through increasing the amount of diesel fuel injected into the engine. An additional benefit of using propane to increase power is that propane is a clean burning fuel, not adding the soot or emissions that diesel fuel does. Considering our power adding options, we decided to try MSD's new system and find out for ourselves how it worked.  Hauling a heavy load? Propane...  Hauling a heavy load? Propane injection can give you the power you need to comfortably haul even the largest load with your Cummins-powered Dodge and will even save you some money in the process!  Can the contents of this propane...  Can the contents of this propane bottle really improve both the power and economy of your Cummins-powered Dodge truck? We were skeptical at first, but after our testing we were nothing less than amazed.  The Digital Propane Injection...  The Digital Propane Injection kit comes with all the components including the wiring harness, lines, connectors, and even additional heater hose to route warm coolant to the propane regulator. Assembly of the regulator was time consuming, but clear instructions made it simple.  The pressure regulator is...  The pressure regulator is fairly complex and comes unassembled. The fuel pressure switch, lock-off solenoid, pressure-control solenoid, boost signal hose, pressure sensor, and mounting bracket all had to be installed on the regulator prior to mounting the regulator assembly in the truck. Be sure to follow the instructions and use thread sealer on all threads when assembling the subcomponents. 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.  Using the mounting bracket...  Using the mounting bracket as a template, we marked and drilled three holes in the passenger-side inner fender to mount the unit. It's a tight fit, but locating the unit per the instructions ensures that it doesn't interfere with the other items in the engine bay.  Once the regulator assembly...  Once the regulator assembly is mounted, we begin our connections by splicing and rerouting one of the heater hoses so that coolant passes through the regulator. This heats the propane ensuring the liquid propane completely converts to a gas at a consistent temperature prior to being injected into the inlet air stream.  The propane discharge nozzle...  The propane discharge nozzle is mounted in the air-intake tube between the air cleaner and the turbo. We used a hole saw to drill a 31/44-inch hole for the nozzle. The nozzle is held in place by a concave washer, nut, and cotter pin to ensure nothing falls into the air stream. Locktite was also used to ensure nothing comes loose. After our kit was installed, we were thoroughly impressed with both the performance gain as well as the increased economy shown in our truck. The system worked flawlessly from the first time we used it and added substantial power to our already healthy Dodge. We tested the system with the truck both loaded and unloaded and were impressed with the improvement in acceleration. We initially programmed the system to give us 100-percent capacity at 5 pounds of boost and expected to feel the system's "hit" when the propane was added. The system operated seamlessly, however, and the only indication that it was working was the speedometer's rapid acceleration to not-quite-legal speeds. Even when only programmed to 50-percent capacity while towing our 10,000-pound, enclosed car trailer, we found we had power to spare. No matter what incline we climbed, simply rolling into the throttle produced not just sustained speed, but acceleration, with transmission downshifts now a thing of the past. Exhaust temperature was also noted to be some 50 degrees cooler for a given driving parameter. A quick trip down the eighth-mile showed an improvement of six-tenths of a second and 5 mph when using the propane, with traction now limiting how hard we could launch the truck. Amazingly, it also makes economical sense to use the system when driving daily. As a function of the extra power on tap, the economy of our truck improved drastically. In a controlled test at 65 mph, our highway mileage in an unloaded truck with the propane shut off was 24 mpg, not bad for a heavy dualie. With the propane injection on and set to initiate at five pounds of boost and give 50 percent of the systems capacity, our mileage increased to an amazing 44 mpg (factoring the diesel fuel used only)! Over a 100-mile test, we used 6 pounds of propane from our 30-pound tank, which cost $18 to fill at the local propane supplier, so the propane used for the test cost $3.60. Diesel fuel for the 100 miles was 2.27 gallons at $3 per gallon for a total of $6.82 in diesel fuel. Added together we get a total of $10.42 for the 100-mile test using propane. Without propane, we used 4.17 gallons of diesel at $3 per gallon for a total of $12.50, so we saved over $2 on a 100-mile test using propane. In addition to the cost savings, the use of propane provided us added range, which allowed us to shop for fuel, saving additional money because we now could go to the next exit or even the next state to find cheaper fuel. Even better results were obtained when towing-we saw mileage increase from 14 mpg without propane to 24 mpg when using propane injection. Our truck's range now had no problem exceeding the endurance of our bladder, even while towing our car trailer. We can derive mathematically that it doesn't take too long for the system to pay for itself, especially when diesel fuel in our area is hovering around the $3-per-gallon mark. What can we say? Easy installation, clean, safe power, improved economy, and a system that pays for itself adds up to one of the best improvements you could make to your diesel-powered truck.  With the air-inlet tube back...  With the air-inlet tube back in place, the propane-injection line can be routed from the regulator assembly to the discharge nozzle. Plenty of line was supplied with the kit. (You'll probably need to cut the line to fit as we did. Be sure to route this line away from potential heat sources and secure it to prevent chaffing.)  After using the supplied tee...  After using the supplied tee fitting to connect the factory waste gate hose to the Boost Pressure Port on the regulator, we connected the wiring to the regulator's fuel pressure switch and our regulator assembly installation is complete.  Following MSD's instructions,...  Following MSD's instructions, we mounted the system's ECU to the forward wall of the passenger-side battery tray. The controller can be mounted in any location, but should be kept away from potential sources of heat. Also consider the length of the wires in the supplied wiring harness. The location we chose works fine, but for ease of tuning you may consider lengthening some wires and mounting the ECU in the driver's compartment to more easily hook up a laptop computer.  Using the supplied wire taps,...  Using the supplied wire taps, we spliced two wires from the ECU into the truck's Powertrain Control Module on the passenger-side firewall. Four additional sets of wires plug into the various connectors on the regulator assembly, the remaining wires are for power, ground, the on-off switch, and the led indicator light. Wiring is straightforward and only six of our wires in the supplied harness needed to be lengthened for our application.  With our system installed,...  With our system installed, we enlisted the guys at Southeast Power Systems in Orlando, Florida, to help with the tank installation. Since the tank must comply with both federal and local regulations, MSD recommends you have a shop in your area install the tank. Southeast Power Systems can service or modify your diesel truck to the extent of your budget and have the parts and personnel to do any job quickly and properly.  Not wanting to lose the utility...  Not wanting to lose the utility of having a full-size truck bed, we chose to locate our 30-pound-capacity propane tank under the bed. unfortunately, the only convenient location in a Dodge requires the removal of the under-bed spare tire and its mounting hardware. In-bed installations are quicker and cost less, but you'll lose the ability to haul four-by-eight foot sheets of construction material.  Two brackets had to be fabricated...  Two brackets had to be fabricated and bolted under the bed to hold the tank mounting brackets. Rather than welding the tank mounting hardware in place, we chose to bolt our unit in that will allow us to remove it and re-install our spare tire later if desired. When modifying your vehicle, we encourage you to think about vehicle resale and make the modifications in a way they can be reversed.  With one bracket in place,...  With one bracket in place, we hold the tank in position to locate the second mounting bracket. When installed, the tank will barely be visible under the truck's bed, though the trained eye may notice the remote filling ports when we show how quickly a propane-injected diesel dualie can leave a stop light!  The brackets that hold the...  The brackets that hold the tank in are latch style. the guys at Southeast Power drill them so that a lock bolt can be installed to ensure the latch doesn't come open while driving. This is one of the tricks that make us glad we went to an experienced shop for the installation of our tank.  With our system installed,...  With our system installed, we can use a laptop computer and MSD's software for both programming and data acquisition. The system comes preprogrammed to inject 100 percent of its capacity for maximum performance, but can be tuned to supply less propane and to begin supplying propane at a certain boost level depending on your driving habits. Of course, we chose the 100-percent setting to satisfy our need for speed, but found that a setting of 50 percent initiated at 5 pounds of boost was best for highway driving and towing. Programming takes just a few minutes and improvements in power and economy far exceeded our expectations.  With the propane tank installed,...  With the propane tank installed, the supply line is run inside the truck's framerail along the same route as the truck's fuel lines. This line will be carrying liquid propane to the regulator assembly and is a steel-braided, high-pressure line with quality AN-style high-pressure fittings at each end.  We opted for a remote fill...  We opted for a remote fill fitting to be located under the rear bumper for ease of tank refilling. Drew at Southeast Power fabricated our fitting before welding it to the chassis-mounted trailer hitch. Refilling the tank can now be accomplished anywhere propane is sold and takes about three to five minutes.
|
|
|