Methanol Injection Install How-To

Written by:Ben Johnson

Date:12-15-2006

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Table of Contents

Title Pagei

Table of Contentsii

  1. Introduction1
  1. Theory 2
  1. Parts Selection4

3.1.Reservoir Tank and Pump4

3.2.Accumulator and Pressure Gauge5

3.3.Lines, Fittings, and Valves5

3.4.Pressure Switches and Wiring6

3.5.Solenoids and Check Valves6

3.6.Nozzles6

  1. Installation Instructions

4.1.Tank Installation and Plumbing7

4.2.Pump, Accumulator, and Gauge8

4.3.Running Feed Tubing and Wire9

4.4.Pressure Switch10

4.5.Solenoids11

4.6.Nozzles12

4.7.Final Details14

  1. Tuning Advice and Conclusion 15

1

1.0Introduction:

Advancements in the aftermarket industry for automobiles changes by the month and finding new ways to set a vehicle apart both technically and competitively is becoming more difficult with each advancement. Popular for decades in the form of nitrous oxide, an alternate secondary injection system has gained intense popularity over the past few years. The following methodology concerns this newer form of secondary injection: methanol injection.

Methanol injection is a specific form of a general category of secondary injection processes using chemicals such as methanol, ethanol, distilled water or some combination thereof. The specific mixtures will be covered, but for the remainder of the document the term methanol injection will be used to cover all these fluids. Also, for a frame of reference, the pictures shown are from a personal install on a second-generation Mitsubishi Eclipse. The car came turbo charged from the manufacturer and the methanol injection kit was assembled piece by piece. While the theories and directions will be kept as general as possible, specific details may be vary for other applications.

Methanol injection can be used on almost any internal combustion engine. Whether it is gasoline or diesel powered, carbureted or fuel injected, naturally aspirated or forced induction, methanol injection can be used to realize power gains. Furthermore, methanol injection does more for an automobile’s engine than just allow for power gains. The fine liquid particles effectively “steam clean” the internal components of the engine and remove carbon build up.

Finally, before jumping into the heart of this document, it should be noted that methanol injection is not an exact science. Without careful planning and execution severe engine damage can occur. Further research will be necessary for most applications and the consult of an experienced installer may be necessary. That being said, the project is enjoyable and not out of reach for most shade-tree mechanics and weekend warriors.

Now onto the good stuff…

2.0Theory

Every successful project should start with some research. Thankfully, most of that is done for you and the majority of the important information is compiled in the following section. Of course, this is only a drop in the bucket when it comes to internal combustion engines, but for the scope of this project it is good start.

Methanol injection does not directly add power, but it does offer a means to add power. Different combinations of methanol, ethanol and distilled water all have their own strong and weak points when it comes to injecting them. It will be assumed for the sake of simplicity that either pure water or a combination of water and methanol is being used. Overall, water or a combination of water and methanol reduces an engine’s tendency to prematurely detonate, commonly referred to as “knock,” due to high intake temperatures. In addition the increased octane rating provided by the methanol creates a slower burning fuel and air mixture that also decreases knock. Also, as previously mentioned either case will provide a “steam-cleaning.”

The next step is to size the system. While the pump, tank, and line size need careful consideration, the main concern is the size of the nozzle or nozzles. When looking for a nozzle, be mindful of the spray pattern it produces. The finer mist or fog that the nozzle produces the better mixture it will make with the intake flow. Ideally, with a fine enough fog the water and or methanol will completely evaporate into the flow. This evaporation is what effectively lowers the intake charge air temperature and allows the methanol to increase the overall octane rating. A nozzle’s flow rate is a function of the pressure of the fluid being feed through it and the pressure of the intake charge. Knowing the flow versus pressure data for the nozzle of your choice is paramount in making the correct decision.

When selecting nozzles the amount of required methanol flow depends upon the mixture used. At this point you have an option to choose between two different injection methods. The first is injecting methanol at a constant rate, and having the threshold controlled by a pressure switch. This system can be set-up with more than one stage that uses different sized nozzles and threshold pressures. The second option is a variable rate system. A reputable kit of this type uses a controller that injects methanol using a high speed solenoid that injects methanol by referencing the automobile’s injector pulses. While the second system is more customizable and tunable, this write-up will concern itself with the first type. Reasons for this are that the first system is considerably cheaper and easier to assemble. It should be noted that changing from a constant injection system to a variable rate system involves minimal addition of parts and wiring.

Constant injection systems use one or more stages that use nozzles that relate to the fuel flow of the engine. On average when pure water is used you want to inject 20% to 30% of your total fuel flow at wide open throttle (WOT). When pure methanol is used the average injection amount is 50% of your total fuel flow at WOT. When a mix of the two chemicals is used some percentage between those listed works, but the tuning required will be different for different mixtures. Simple calculations involving injector duty cycle manufacturer’s flow rate will give a good indication of the amount of secondary injection needed. There are also detailed spreadsheets available that allow for a finer calculation.

While there is much theory and discussion that could be had concerning a system’s other components, the most important point of nozzles was covered and a brief overview of the remainder of the system will be covered in the following section.

3.0Parts Selection

The following section gives a general parts list and reasoning for certain choices. Detailed part numbers and quantities will be dependent upon the end-user’application. In Figure 1 below is a shot of the parts involved in my methanol system. Omitted are the reservoir tank and gauge.

Figure 1: General overview of the parts involved with a methanol injection system. Omitted are the gauge and reservoir tank.

3.1.Reservoir Tank and Pump

When designing a methanol injection system the tank is one of the first issues that needs addressing. Placement and size are the main concerns. For the Eclipse featured in the photos, the stock windshield washer fluid reservoir tank was used. With a one gallon capacity it is big enough to last for quite a few days and the placement remains stock. This stock location allows for full use of the spare tire and prevents the necessity of adding a bulky tank to the hatch area. For cars where this is not an option, small fuel cells or heavy duty methanol safe plastic containers may be used. If underhood room is plentiful the tank can be placed there, but care must be taken to ensure adequate room for the pump and accumulator.

The heart of any injection system is the pump. For non-preassembled kits like the one featured in this write-up, Shurflo brand pumps have quickly become the favorite. While a kit can be assembled using a 60 psi model, it is not recommended to use anything less than their 100 psi model. Coolingmist, a company specializing in methanol injection systems, and Shurflo teamed up to make a methanol-safe pump capable of 150 psi. I used this pump because of its methanol-safe capabilities and because the higher pressure means the use of smaller nozzles resulting in finer atomizationand better charge air cooling.

3.2. Accumulator and Pressure Gauge

An accumulator works as a buffer for the pump. It contains a small storage of pressurized fluid within itand absorbs any pulses or pressure spikes from the pump. Also, the accumulator’s stored fluid allows the pump to operate more smoothly without the need to cycle several times a second. The larger the accumulator the better buffer it will provide, but there is obviously a limit when the accumulator is too large to fit in the space allowed and for the pump to fill. Most systems use a Shurflo accumulator, but because of the pressure limit of this accumulator being 120 psi another solution was needed. The pictured Watts accumulator began life as a water hammer arrestor used in home plumbing systems. With a maximum pressure of 200 psi, it fits very well with the Coolingmist pump.

Although not entirely necessary to have, a water pressure gauge is a nice addition to any injection system. Most of the methanol pumps listed above have an adjustable pressure switch that needs to be set. Without a pressure gauge this can be a difficult process. When adding a gauge make sure to use a high quality glycerin fluid model that can absorb the pulses from the pump.

3.3.Lines, Fittings and Valves

There are two options when it comes to choosing feed lines and the associated fittings and valves. One option is using braided stainless steel line and A/N fittings. This option looks very professional and is of the utmost quality and durability, but will drain the pocketbook quickly. The other option is to use nylon tubing and brass compression fittings. While they may not look as nice, the price is reasonable and the end product is reliable.

For the methanol system discussed here, nylon tubing was ordered from McMaster/Carr that could withstand the 150+ psi pressures the system was designed to run. Standard brass compression fittings were purchased from a local hardware store. The list of fittings necessary will change for each application and going to the store with a list of the needed fittings and reducers is highly recommended. It is also recommended to install a manual valve after the pressure gauge and before the line incase of leaks or for any maintenance.

3.4.Pressure switches and wiring

The subject of wiring could be a whole other write-up in itself. However, because of the general overview style of this instruction set, I will keep it brief.

To activate the solenoids used to inject the methanol a pressure switch is commonly used. These pressure switches, usually made by Hobbs, can be purchased from most auto parts stores. They are wired in-line from the 12v power source to the solenoid and act as a switch that is activated by a pressure source, usually from manifold (boost) pressure. They also have a set screw on them that is used to adjust the threshold pressure required to active the internal switch. The rest of the wiring will be covered in the installations section, but for reference any quality shielded is recommended. Also, fuses, relays and terminals may be necessary.

3.5.Solenoids and Check Valves

The solenoids and check valves chosen for a methanol injection system can make or break the reliability of it. If a solenoid were to stick open it could inject methanol into the intake while under no load. This could result in a very dangerous explosion or hydro-lock of the engine. If a solenoid were to stick shut, the car would run extremely lean during WOT operation and could cause serious engine damage. It is for these reasons that a high quality stainless steel solenoid is recommended. McMaster Carr sells a stainless steel model that has the electronics enclosed in epoxy to prevent moisture damage.

Some systems use preloaded check valves as the activation mechanism. While this would alleviate the need for pressure switches and solenoids, the reliability and controllability of the system is erased. Check valves should only be used close to the nozzle to prevent back flow and methanol being drawn into the system unintentionally.

3.6.Nozzles

Methanol injection nozzles come in a variety of types. The company Aquamist sells highly precise low flow nozzles that work very well with the system for which they are built around. For the purposes of a do-it-yourselfer, Bete brand nozzles are recommended. Most people tend to use the M series nozzles. While inexpensive, their spray pattern pales in comparison to the more expensive Bete PJ nozzles. Nozzle flow rates are rated by pressure, knowing the pressure your system is running at and the expected boost pressure, the proper nozzle can be chosen.

4.0Installation Instructions

Now that the theory and parts involved with installing a methanol injection system have been introduced, the next step is pictorial instructions detailing the installation. The specific parts involved were outlined in the Parts Selection section. While I believe these parts make a very reliable and customizable single stage injection system, other parts may be used successfully also.

4.1.Tank Installation and Plumbing

Figure 2 below shows the stock washer fluid bottle on an Eclipse. While there is no photo of them, the stock pumps and lines for the washer system are located underneath the tank. Because these pumps allow the fluid to be drawn through without power, it is a simple job of teeing off one of these rubber lines with another line that goes to the input side of the pump. The use of the stock tank has many advantages. For one, there is no need to fit an extra tank in the hatch. Also, the stock tank has a low level light and therefore does not require the addition of a level sending unit. On the other hand, if you do need to add a tank make sure to secure it well as a methanol spill would not be good.

Figure 2: View of the stock washer fluid bottle. The feed lines are beneath the tank on the passenger’s side.

4.2.Pump, Accumulator, and Gauge

Figure 3 shows the installed pump, accumulator, and gauge place holder. All the brass fittings were found at a local hardware store. I used ¼” NPT for the reducers and fittings and ¼” compression fittings for the brass to nylon tube connections. Make sure to use Teflon tape on all male threads and to tighten the fittings well. One of the final processes is to do a leak test, but doing it right at this point will alleviate headaches.

  • Find a suitable place for the pump where you will have room to fit the accumulator, gauge, and shut off valve.
  • Once situated, mark the holes in the pump base. After making sure there are no obstructions under the car where the hole are to be drilled, pre-drill the holes.
  • Assemble all fittings and thread them into the pump inlet and outlet. Be careful not to crack the pump housing. Orient the accumulator and gauge tees so they will fit in the space provided.

Figure 3: Installed pump, accumulator, and gauge. No gauge is shown as it was delivered wrong. Also note the tee for the feed line.

  • Charge the accumulator to 10 psi less than what the system will run at. Since my compressor would only output 120 psi, it was necessary to use a bike pump to reach 140 psi
  • Secure the pump and the attached fittings using self tapping sheet metal screws. My gauge was delivered incorrectly at the time these pictures were taken and a plug was put in its place.

4.3 Running Feed Tubing and Wire

This process will be different for all vehicles and owner preferences. Generally, the feed line will be run from the pump to the engine bay, a switched power wire will be run to the pump, and a multi strand wire will be run for diagnostics LED’s. Below I have included several pictures showing a typical install and the work involved. Also, I have outlined a typical wiring scheme and route for running the tubing and wire.

Figure 4Figure 5

  • Above Figure 4 shows the power supply setup for the pump. Already having a 10 gauge wire running to the fuel pump area provided a fused circuit to splice into. Using an additional relay controlled by a toggle switch in the glove compartment power was run from this relay to the methanol pump. This set-up offers another fail safe as the methanol pump cannot be activated with out the fuel pump being on.
  • The methanol tubing was run under the hatch molding, next to the relays in Figure 4 and along the door sill to the spot it is pictured in Figure 5. From here it is feed through a rubber boot into the engine compartment.
  • The coiled up gray wire in Figure 5 is a multi strand wire that is used to activate the LED’s located on the center console. The individual wires in this gray wire are used for the following:
  • Switching the relay
  • Lighting an LED to show power being delivered to the relay.
  • Lighting an LED to show power being delivered to the pump.
  • Lighting an LED to show that the pump is turned on and pumping methanol. This wire is spliced into the pressure switch circuit on the pump.
  • Lighting an LED to show that the threshold intake pressure is reached and the solenoid is open and methanol in being injected into the engine.
  • Figure 6 below shows the finished wiring and plumbing for the rear of the car. Taking time to cleaning install and wire and tubing allows for easier trouble shooting.