Boost Juice

In-Depth Testing: Snow Performance Water Methanol Injection
What is water-methanol injection and how does it apply to me? By injecting a mixture of water and methanol into your engine’s intake, you can reduce your exhaust gas temperatures by up to 300 degrees; increase horsepower by up to 75 hp; increase miles per gallon; reduce tailpipe emissions; and reduce DPF regeneration cycles significantly. All while providing safe, reliable power.


While it’s only become a hot topic in the diesel performance industry in the last several years it’s not new technology at all. During WWII, the US military injected a mixture of “water and alcohol” into the intakes of P-47 Thunderbolts, which netted them an extra 400 horsepower for takeoffs and dogfights. This extra power also came with the added benefit of reduced fuel usage when the system was turned on. Which was something these thirsty rotary engines really needed when escorting bombers over long distances. In prior testing with our 7.3L Power Stroke using Snow Performance’s MPG Max kit, we netted an extra 53 horsepower across the powerband, 1-2 mpg gained on flat roads and 9 mpg added on hills, all with EGTs so low we didn’t bother worrying about them at any time. No joke, we saw a maximum of 900 degrees from the pyrometer when towing 10,000 lbs up a 6% grade at 65 mph.


1 & 2 The water-methanol mix will be sprayed into the intake post turbo as close to the engine as possible. So the first step was removing the LMM’s intake horn, a procedure that took us roughly 45 minutes to complete.
3 With the intake off the truck and secured in a vice it was time to drill and tap three holes: one for a boost signal to the Snow Performance Controller, and two for the nozzles. Before removing the intake completely we first checked clearance for the three fittings. Behind the intake gave us plenty of room and as a bonus kept everything under the hood looking stock.
4 We started drilling the cast aluminum intake manifold with a ¼-inch bit and then stepped up to an 11/32 bit before tapping the holes.
5 The only specialty tool required for this install is a 1/8-27 NPT thread tap. It’s a tapered tap as the threads are designed to be the seal between the boost and atmosphere. Because of this taper, it’s extremely important not to overtap the hole. We ran the tap about 50% down and the nozzle fit perfectly.
6 A bit of sealant supplied by Snow was then applied to the nozzle’s threads to
provide a bit of overkill in the sealing department.
7 Here are the two nozzles installed as well as the existing aftermarket boost fitting with the Snow Performance boost reference fitting next to it. Notice how the nozzles are installed with the screen filter outside the intake. This is the correct way to install them. Also notice we wrote the size of the nozzle installed next to it with a sharpie. The nozzles come in many different sizes depending on your needs. We installed a small #3 nozzle for the first stage and a larger #6 nozzle for the power setting. We’ll play a bit more with tuning this kit using different nozzles in a future project installment.
8 With all fittings installed onto the intake horn, it was then reinstalled on the engine. Next, the boost reference line was plugged in as were the two nozzle holders (seen here).
9 Here’s the solenoid used for the power setting. When the engine reaches a preset boost level the VC 50 controller sends a signal to the solenoid, opening it and allowing much more water/methanol to be injected into the intake.


10 & 11 We mounted the solenoid behind the passengerside battery for ease of access but also due to its close proximity to the pump and injection nozzles. From the pump the supply line splits off; one end feeds the smaller of the two nozzles in the intake and the other goes to the power solenoid which feeds the larger #6 nozzle.
12 The next step was mounting the pump, which we did as close to the tank as possible to minimize priming times. In our case this meant it would be secured to the back of the cab just outside the frame rail using the four supplied self-tapper screws. This pump is extremely quiet; not once have we been able to hear it operating.
13 We decided to use Snow Performance’s 7-gallon reservoir for Project Mundane, which gave us a 700-mile range unloaded and without a trailer. If you need a larger supply than 7-gallons, Snow also offers a 10-gallon wheel well tank. Both require a few holes to be drilled, one for the supply line and four for the mounting hardware. For the supply line we made sure to drill the hole large enough to fit a rubber grommet around the line to protect it from chafing damage.
14 The final piece on the install list is Snow’s VC 50 controller. It’s a 2-5/16-inch gauge so it’ll fit into any preexisting gauge pod, or you can mount it with the pod Snow Performance supplies. If you already have a set of gauges you can simply swap this one with your boost gauge (it’ll show boost whether the kit is turned on or not).
15 For the utmost visibility (but also because the pillar is already taken up by all our other gauges used for our own testing purposes) we mounted the VC 50 controller right on top of the steering column. For those who don’t have data logging equipment on their vehicles like we do, we recommend mounting the controller on a pillar pod or the like for a super clean “factory-like” look.
16 Wiring the controller was quick and easy, requiring only five connections: the mechanical boost signal from under the hood (which we installed in the intake earlier); power to the pump; power to the solenoid; a key on 12V signal; and a ground.

For this issue we’ll be installing Snow Performance’s Boost Cooler on Project Mundane, a 2008 LMM Duramax-equipped Chevy. Project Mundane isn’t really as boring as it sounds, but with all the over-the-top, high-horsepower builds we’ve been doing lately we figured we were past due for an “everyman’s build.” Project Mundane will be the perfect daily driver/weekend warrior once it’s done and the added benefits from a little bit of water-methanol injection are perfect for this truck. In this issue you’ll see the install, but make sure to check future issues of Diesel World where we’ll share our long-term test results. We’re expecting to see some great things from this LMM with its new Snow Performance system. Stay tuned. DW



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