Water Injection

AEM Power

June 2014 Installs

When it comes to making power and doing it efficiently with your truck, there are really only two things your engine needs, air and fuel. Fuel upgrades come in the form of performance tuners, larger injectors and modified injection pumps, but since an internal combustion engine is nothing more than a self-propelled air pump, the easier air can be pushed in and out of it, the more efficient and better that engine can be at making power, especially if you’ve already made fueling changes. To do this common upgrades have always been cold air intakes, larger straight flow exhaust systems, complex turbochargers and intercoolers with more efficient cores. But one of the least expensive and easiest to install options that are often overlooked when it comes to changing the way incoming air is fed to your engine is the addition of a Water Injection system.

AEM Power of Hawthorne, Calif., has been engineering and building water injection system for both gas and diesel applications for a few years now and has just recently released the all new HD Diesel specific kits that can not only improve horsepower and torque, but reduce Exhaust Gas Temperatures and emissions particulates while increasing your fuel mileage. With two new options to choose from, AEM Water Injection can meet the demands of just about any diesel application from a stock truck used for towing on the weekends to a full competition drag race or sled pull truck. Before we get into particulars about each system and which is best for you, maybe a little insight as to how water injection actually works.

How It Works

Since your diesel only needs air and fuel fed into the combustion chamber, how and when they enter the cylinders will control what kind of atomization and performance you’ll get in return. In our sixth grade chemistry class we learned about air and water molecules and how cooler air means denser air. Denser air means more oxygen in a smaller place, and in a small space like a combustion chamber, more air is going to make for a bigger ‘explosion’ which results in more power. So in order to get denser air into our cylinder heads and combustion chambers, we bolt on cold air intakes and more efficient intercoolers and turbochargers for our application. Cooler air charge going into the engine makes for a denser air charge, so more fuel can be burned. Water Injection system work under much the same pretense, except they drop that charge air temperature chemically by injecting water at a high pressure into the air stream just before the intake manifold where the water atomizes into the air before it enters the combustion chamber. Dropping the air inlet temperatures with water effectively lowers Exhaust Gas Temperatures, which can be very beneficial while towing, allowing you to use more of the power you already have. The denser air charge also helps create that more efficient burn we talked about which equates to lower emissions and fewer particulates being expelled through the exhaust system. Lastly, by using water you’re effectively adding a fuel into the cylinders which can generate even more power and torque.

New And Improved

After spending hundreds of hours engineering and testing their new systems, the folks at AEM Power have released new diesel specific system that are not only more effective than previous versions, but are easier to install and more user-friendly. For the average diesel owner, that has done basic upgrades to their daily driver looking to improve its towing or street characteristics, its new Boost Dependent kit makes for a straight forward installation that can give them all the benefits of water injection without the headache and hassle of installing and setting up like other kits on the market. The newly redesigned controller is the brains of the system and uses an in-board MAP sensor (up to 40-psi boost) to relay your trucks boost pressure to the injection pump to control water output. The controller has just two control knobs to set the boost pressure your water injection starts and a second to set what pressure max injection should be reached. All new fluid maps have been programmed into the controller as well to maximize water injection efficiency through a more linear delivery throughout the boost range.

Go With The Flow

Their other option is for the higher performance and higher boost applications that would like to set their water injection flow strategies to match the demands of their engines. This HD system is the perfect option for engines running higher than 40-psi boost pressures as it features a multiple input design that can be programmed to accept a 0-5V signal from an external MAP sensor. The HD system can also use Injector Duty Cycle, frequency based mass airflow (MAF), or a 0-5V MAF signal to control your water injection tables.

Both kits use come with a 5-gallon fluid reservoir, which has a newly designed conductive style low fluid level sensor to warn drivers when their water is about to run out.  AEM Power has also redesigned their billet machined water injection nozzles to maximize fluid atomization and better match the flow delivery required in a diesel application, each kit comes with three nozzles to choose from depending on your engine’s needs. Their high flow recirculation style 200-psi pump uses robust integral fittings for quiet operation. An easy color coded wiring harness with positive clip connection and an easy to follow diagram makes the wiring process much simpler.

AEM Power has been an industry leader in Water Injection systems and with these newly improved diesel specific kits it’s a sure win-win situation for all of us. Better engine efficiency, more power, cooler EGT’s and lower emissions. On that note, it’s also worth mentioning that AEM Power offers the only 50 State legal Water Injection kits for diesels, so for those of you with 2008+ DPF equipped trucks or those of you in California, a CARB certified system is also available.

1 – The latest generation of Water Injection kits from AEM Power has become easier and more effective than ever with its new Diesel High Boost and 50 State legal systems. Using a completely redesigned controller offered in two versions depending on your application. More efficient injection nozzles designed specifically for diesel trucks ensures proper water atomization for the ultimate in EGT control and efficiency. Its unique 5-gallon fluid reservoir mounts nicely in the bed and allows for extended range for towing applications. 

2 – AEM now offers their diesel systems with two controller styles to best fit your particular truck. Its Boost Dependent controller has a built in MAP sensor that receives a boost reading from your engine to relay to the pump for controlling injection start and progression. The second HD controller uses a multiple input design that allows you to feed a 0-5v signal to the controller from your external MAP sensor. This option will work great on high boost applications (40+psi) as it will allow a proper injection scale per your trucks boost range. This controller can also use an outside Injector Duty Cycle or MAF signal to control your water injection timing.

 3 – In redesigning their controllers, AEM also opted to switch over from their previously hardwired controller to a pigtail and harness connection; this change will make installation of both the HD and Boost Only kits much simpler and quicker.

4 - AEM Powers recirculation style pump with integral fittings ensures reliable and quiet operation.  The 200-psi pump allows water to be injected at the perfect pressures to ensure proper atomization and efficiency. The pump is also designed to allow any mounting orientation to make installation easy for just about any location on the vehicle. No need to worry about keeping it upright, just as long as it is in a safe place away from excessive road debris and weather. 

5 – After hundreds of hours of research, engineering and testing AEM feels confident that their new injection nozzle design is unmatched on today’s market. Each kit comes equipped with two injector assemblies and three nozzles to choose from to maximize performance for each vehicle. The revamped injection strategy in the controllers for improved seamless injection and flow matched to your engines output.

6 – A newly designed Low Level Indicator comes pre-installed in the 5-gallon tank. The conductive style sensor has a positive lock connection and wires color matched to those in the kits wiring harness to ease installation and ensure a proper water level reading at all times.

7&8– The first part to our water injection install was finding the best location in the bed for the reservoir and getting it mounted. We decided that front passenger side corner would work best and made sure to check the underside of the bed for any wiring or hoses before drilling our holes for the mounting bolts. After finalizing our mounting location, we were able to mark the bed and remove the tank to begin drilling. Don’t forget you’ll need to drill an additional hole to run the water line and fluid level sensor wire through.

9 – After getting our fluid tank mounted in the bed it was time to install the fluid pump. Due to the injection system design and how it functions, it’s vital that the fluid pump be mounted at a lower position on the truck than the tank; this will keep the pump from working too hard drawing fluid from the tank. This will also ensure that any water left in the lines after an injection event can stay in the lines and not drain into the engine. We opted for a spot under the cab on the backside of the weld seam. We used a piece of card board to mark the four mounting points and be sure we drilled where we needed to.

10 – Mounting the pump under the truck in this location will keep it lower than both our fluid tank and injection nozzles and is in a position that will keep it away from any road debris. Being able to mount the pump at a slight angle under the truck allowed us to keep it tucked up out of sight and eases our water line routing in and out of the pump itself.

11 – The last hard part to install was the water injection nozzles themselves. On our 7.3L Power Stroke, one nozzle should be suffice for EGT control, so we opted to install it in place of the Air Intake Heater in the intake manifold using a Plug and Adapter from Driven Diesel. This made for a simple no drill installation. Should we decide the second injection nozzle is needed; we’ll just drill and tap a location near this. With the tank, pump and nozzle(s) installed, we just needed to route the black plastic water lines from the tank to the engine then it’s on to the most time consuming step, the wiring.

12 – The HD and Boost Only controllers and wiring harness couldn’t be simpler to install with color coated wiring and a simple diagram and schematic to help you along each step of the way. While it is an easy job that requires just a basic knowledge of electrical wiring it does take some time to accomplish this, taking your time to make sure your connections are secure and wires are routed smartly can help make this a seamless, near OEM style installation that can look like it came factory equipped.

13 – The kit comes with a complete positive lock connection style harness along with all the required wire connectors, fuse taps, hoses, and even zip ties. You’ll need a set of wire pliers for cutting the shielding off the wires and crimping your connectors. Soldering skills, while not required could make this a cleaner more secure permanent installation as well.

14 – By just following the AEM wiring diagram step by step you can one by one run each wire to its required location make your connections and move onto the next. Here, the pink wire from our harness is being connected to the red wire of the pump under the truck.

15 – Once all our wire connections had been completed, we could then turn to testing, adjusting, and mounting our controller in the cab. The plug in wire harness was connected and our initial water injection settings were adjusted to start water injection at 7-psi and ramp up to full injection at 30-psi. The kits instructions suggested we set our ‘Start’ knob at 25 percent of our max boost and the ‘Full’ knob at our trucks highest boost output.

16 – With the hardware and wiring all completed, the last step was to tap into a boost source to feed the required boost pressure to the controller’s internal MAP sensor. To do this, we spliced into our trucks MAP line and place a brass tee in the line, using the supplied rubber hose we routed it from this line through the cab and into the controller. Only thing left to do now is fill the reservoir with fluid and go and do some testing.

While we used this slightly modified 7.3L Power Stroke for our installation, the HD and Boost Only AEM Water Injection systems can be used on any make or model regardless of performance level. Whether you’re driving a basically stock truck and just looking for better EGT control while towing or ripping down the drag strip in a 600+ horsepower high boost street stomper, these kits can be adjusted to fit your needs. AEM also offers the only 50 State Emissions Legal kit on the market for those of you hesitant due to local CARB or Emissions Regulations.

For more information on these kits and other AEM Products, like its Brute Force Intakes, visit www.aempower.com or call 310-484-2322.

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