Water/Methanol Injection on 6.7 Cummins

December 23rd, 2009

Snow Performance’s Bolt-on Power producer for the 6.7 Cummins

Within the industry, it’s known as water-meth injection. Sounds more like a serious drug problem more than a way to generate more power from an engine.  Water-methanol injection has been around for quite some time, having been used on supercharged and turbocharged gasoline engines for years to knock down detonation under boost.

For years, water-methanol injection has been one way of cooling the intake charge on supercharged or turbocharged gas engines. Often called “chemical intercooling,” the water “absorbs” heat out of the intake charge while the methanol is essentially an octane booster for the combustion chamber. For gasoline engines, the system acts as a detonation suspression system which allows more ignition timing under boost.

Most recently, that same technology has been applied to diesel powerplants. While the principles are similar, water-methanol injection on a diesel has the added benefit of lowering exhaust gas temperatures (EGTs) while the methanol acts as a burn catalyst for the fuel, producing more power and added mpg.

Snow Performance in Woodland Park, CO, is a recogonized leader in water-methanol injection technology. As vehicles have become more technologically advanced, so have Snow Performance’s water-meth injection systems. They offer several easy-to-install, bolt on kits for both cars and trucks, and have a complete line of systems for diesels as well. Matt Snow, owner of Snow Performance, explained that their diesel system injects a mixture of water and methanol into the air intake after the intercooler.

Injection is controlled by an in-cab controller that references turbo boost pressure and exhaust gas temperature. The methanol acts as a combustion catalyst and helps to give a more complete burn of the diesel in the cylinders. The water quickly turns to a vapor, therefore cooling the air going into the engine.

Snow Performance offers three levels of water-meth injection systems for diesels. For this application, Snow provided their Stage 3 Diesel Boost Cooler system that essentially is computer control for fool-proof operation. The system comes complete with all the necessary hardware, plumbing and fittings for an easy install and is vehicle specific to makes things easier.

The Stage 3 controller includes readouts for EGTs and boost, and even has a switch that turns off the EGT sensor which allows the system to reference boost only, which is great for generating immediate power such as in drag racing.

Based on what Matt told us, we were anxious to apply this new technology to Dodge’s latest, emissions-controlled Cummins. Initially, we has some reservations about how the emission control systems on the new diesel engines would react to the water-meth injection, so we contacted BullyDog and asked if we could install the Snow Performance water-methanol injection kit on their new 6.7 Cummins.

This engine features the latest in `08 emissions equipment including an exhaust gas recirculator (EGR) and exhaust particulate filter and probably enough electronics and computers to run the space shuttle. So if the kit would work on the new 6.7, it could work on any truck.

The new Cummins 6.7 was also a great test mule for the engineers at Snow to have some real world, hands-on experience with the newest in diesel technology.   Snow Performance stepped up to the challenge since this was the first install they had done on the 6.7-liter engines. Nathan Stewart, one of Snow Performance’s technicians, came up to Bully Dog’s facility in Idaho to assist Bully Dog’s Jared Brown with the installation.

The photos highlight the install process. Once completed, the truck was rolled up on the dyno for some pulls. The results showed a gain of 103 hp and 289 ft-lbs from the Snow Performance Stage 3 Boost Cooler water-meth injections system with the Bully Dog Power Pup on Tow setting. According to Snow, this is about where most enthusiasts need the power, towing long grades with heavy loads without reaching nuclear meltdown exhaust gas temps.

And with the Power Pup on Extreme setting, the water-meth system added 46 hp and 51 ft-lbs. We were not able to prove exactly why the gain was smaller with the Power Pup on Extreme but here are a few of the theories from the engineers.

First off, the truck was not able to build full boost on the dyno because the dyno couldn’t provide a large enough load, so the truck may have had more horsepower on the road, but we could not see it on the dyno.  Secondly, the engine may have been over fueling because of the amount of diesel being injected, due to the Extreme download. There also may have been some interference from the ECU, such as a factory torque-limiting program,  that was limiting the power output.

But the testing did show us that the Snow Performance, Stage 3 Boost Cooler does provide a significant power increase while reducing EGT’s. And we were not able to detect that the water-meth caused any issues with the particulate filter or EGR since no check engine lights came on during the testing.

So if you’re in the market for an easy add-on power producer, and are a little gun-shy about nitrous or propane injection, then Snow Performance’s Water-Methanol injection might be the ticket for you. The folks at Snow say a lot of their customers are serious tow guys looking for more power and reduced EGT’s when pulling those long grades, and some improved mpgs in the process.

1. Snow Performance supplied their Stage 3 Diesel Kit. This kit comes with an in-cab controller that controls the injection by monitoring boost and EGT’s, it also allows the user to change the amount of water-meth injection electronically.

2. Snow Performance sells a pre-mixed liquid they call Boost Juice which is 50/50 mix of water and methanol but windshield washer that contains methanol works well also. Most winter formula windshield washer fluids that are rated for -20 degrees Fahrenheit contain about 40% methanol but it is recommended to carefully check the ingredients before using. Boost Juice works as a windshield washer so the stock windshield washer reservoir can be used.

3. The Stage 3 Kit comes with a 2 quart plastic bottle to hold the water-meth but Bully Dog wanted the install to be as stealth as possible so they decided to utilize the stock windshield washer reservoir. Unfortunately it seems that Dodge built the rest of the truck around the windshield washer/engine coolant reservoir, because it was difficult to remove. Nathan removed the driver side headlight and the inner fender well and with a little muscling was able to remove the bottle down through the fender well.

4. The 6.7 Cummins uses a partitioned reservoir for the engine coolant and windshield washer fluid. With the bottle out of the truck, Jerad drilled a 9/16″ hole in the bottom of the bottle.

5. A push-to-connect fitting is installed from the inside of the reservoir. Nathan applied plenty of sealant to the fitting to help prevent any leaks.

6. Jared and Nathan reinstall the reservoir up through the fender well.

7. Next step was to remove the intake elbow, the intake elbow on the Cummins has a built in EGR valve so all the EGR hook-ups had to be removed.

8. With the intake elbow off of the truck, Nathan drilled three holes; two holes for the water-meth injectors and one for boost pressure pick-up. The holes were tapped and compressed air was used to blow out all the fillings.

9. Jared reinstalled the intake elbow on the truck.

10. For installations on Dodge Cummins with a stock front bumper, Snow Performance recommends bolting the pump assembly to the bumper mounting bracket. BullyDog’s 6.7 is equipped with FabFours aftermarket bumpers so the mounting location was slightly different. Jared bolted the pump to a metal plate on the driver’s side of the winch.

11. Jared mounted the controller next to the gear shift, this location was picked because the driver can easily see and adjustthe controller without it being intrusive or looking out of place on the dash.

12. All the components were connected into the stock electrical system and an arming switch installed underneath the steering wheel. The guys also removed the exhaust manifold and installed a pyrometer probe to pick up pre-turbo EGT’s, the probe was then wired into the controller.

13. With the installation almost complete, Nathan filled the reservoir with Boost Juice.

14. Before installing the injectors into the intake elbow, Nathan verified they were functioning correctly. And they worked! We all got covered in water-meth taking this shot.

15. The installation was now complete so we strapped the 6.7 onto BullyDog’s Mustang dyno to measure the gains from the water-meth. BullyDog’s 6.7 was equipped with their RFI intake, 4″ particulate filter back exhaust, and Power Pup downloader.


Without water-meth:         400 hp          935 ft-lbs
With 75% water-meth:       424 hp          885 ft-lbs
With 100% water-meth:     446 hp          986 ft-lbs


Without water-meth:         291 hp          581 ft-lbs
With 100% water-meth:     394 hp          870 ft-lbs


Snow Performance

Bully Dog Technologies


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