Snow Performance President Matt Snow took a call from a representative at Wal Mart’s corporate headquarters. They had recently learned that people were buying windshield washer fluid by the gross for their “water meth” injection systems. Wal Mart wanted to know what water-meth injection was and whether it was legal.
No subterfuge, here. Short for water-methanol injection, water-meth systems, such as those from Snow Performance offer distinct performance advantages and safeguards for cars and trucks with forced induction, high compression and diesel applications. To find out what water-methanol injection does, we caught up with Snow by phone at his office in Woodland Park, Colo.
Put simply, water-meth injection is essentially a chemical intercooling process that cools the incoming air charge, raises the net octane to slow down the flame front in the combustion chamber. The process also reduces combustion temperatures.
“The more spark-knock limited it is, the better we do,” Snow said. “Anything supercharged we do well, because they’re all limited by the fuel and spark knock, so guys running pump gas, we inject (into the system) and it’s like a huge intercooler cooling the air charge down, and we really slow the flame front down like race gas. So the guy can run his blower as fast as he can possibly go and not have any spark knock.”
The same goes for turbocharged applications. Water-meth injection also lets you do a lot of things with timing and with boost to improve power and not get any spark knock. Here’s how the system works.
Depending on the application, the Snow Performance kits come with a pump, hardware, wiring, a water-meth reservoir and controller for tuning purposes. The system reads various engine signals to determine how much fluid to inject. For instance, if it’s a normally aspirated, high-compression engine with a carburetor, the system monitors vacuum and rpm, and injects based on those two parameters to deliver the right amount at the right time.
“If we have a more modern car with a mass-air-flow sensor, we can read that and inject based on that signal,” Snow said. “If it’s boosted, we can always do boost or fuel injector pulse width. We use a variety of parameters depending on the application to command injection.
“They’re pretty much plug and play,” he continued. “The instructions will tell you if have a given engine, set your controller up this way and start with these settings and you fine tune from there. You can spend five, 10 minutes and have it right on the money.”
Snow said he prefers injecting the mixture into the intake before the throttle body because then the system doesn’t require an antisiphon solenoid for idle speeds. It’s a simpler setup. When the throttle blade is closed at idle, you don’t draw any fluid in at that point. The pump, which doesn’t draw much amperage, puts out 300 psi at its highest pressures. The fluid is routed via tubing to a nozzle in the intake, after the mass air flow sensor and intercooler if it has one.
“We’ve got a nozzle that has a spinning mechanism that has a spring-loaded fluted insert that makes the fluid spin inside of a chamber,” he said. “Then, as it’s spinning supersonically it’s forced out of the orifice. That’s how we make the 10 micron mist. It’s a good way to get a fine mist without having to have a thousand psi. Pressure gets expensive and this is a better way to do it. This has proven to do the job and do it well, and it’s relatively inexpensive simple way to do it.”
Using Snow Performance’s proprietary 50/50 blend of methanol and purified water the effective octane can be raised to as high as 116 points. Most of his customers don’t need 116 octane, so filling the system with -20 F windshield washer fluid — about 33 percent methanol — raises it the octane level to about 110, which is plenty for most applications.
Methanol differs from ethanol in that it is a byproduct of wood. Ethanol is made from corn. Methanol is typically less expensive than ethanol and it’s a better antidetinant. It winds up being cheaper and more convenient than buying race gas, but you might find yourself going to Wal Mart for windshield washer fluid by the case. Refill intervals vary.
“It depends on the horsepower of the engine and how it’s used,” Snow said. “We have 400 horsepower Mustangs that are street driven — supercharged cars — that will go 15 gallons of fuel for a couple of quarts of water meth on the street. Then we have some road-racing cars with 600 horsepower that will go through a gallon in 20 minutes.”
The benefits for racing are clear, but water-meth injection also is a plus for diesel applications, which is great for towing your racecar to the track. Because water-meth injection keeps exhaust gas temperatures down, engine reliability is increased, as is performance.
“What you’ll see is an exhaust manifold that cracks over time because the silicon is taken out of the metal. Also, you’ll see bad turbo bearings because of exhaust gas temps where the turbo gets so much slop in the wheel because of continued high EGTs,” Snow said. “Very common in the modern turbodiesels is dropping a valve seat because of high combustion temps. Everyone has pressed-in valve seats now and they’re dissimilar metals to the head, and over time heating them to very hot and cooling they’ll drop and you can wreck a cylinder.”
Lower EGTs let you climb steep grades without fear of burning up the engine. Water-meth injection also lowers NOX emissions, adds horsepower and is California Air Resource Board legal. That’s a handy power mod now that owners can no longer remove the diesel particulate filters.
“The beauty of the new cars is that you don’t have to do anything to them,” Snow said. “You just put our system on and they have closed-loop knock controls. They’re also very temperature sensitive, so if we cool the air charge down and keep away spark knock, they add their own timing. They kind of tune themselves.”