Ultimate Methanol Injection Guide

Joe Terrell
04/13/202113th April, 2021
Filed under Beginner Guides
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Methanol injection comes with many benefits, but there are a few downsides to consider. We’re explaining everything you need to know in this guide.

methanol injection

Introduction

Although many tuning enthusiasts may think that methanol injection is a relatively new addition to the scene when it comes to achieving power gains on your petrol or diesel engines, that’s not the case.

Just like nitrous oxide and forced induction, methanol injection use goes way back to World War II, with the German’s taking advantage of the numerous benefits from meth injection in their fighter planes.

With limited length on their aircraft carriers, they used methanol injection to their advantage, providing a much-needed additional boost to ensure they cleared the runway before take-off.

After seemingly being overlooked until recent years, an increasing number of tuners have been exploring the potential that methanol injection has to offer, and the results have been impressive.

Whether you’re looking to achieve power gains from your drift car, streetcar, or even your hot-rodder, methanol injection should be a definite consideration, and we’ll be explaining the many benefits in this guide.

How Does Methanol Injection Work?

Although considering using meth in some states will undoubtedly leave you with visions of gapless smiles, it turns out that engines respond far better than the human body to meth use!

Despite being most commonly known as meth injection, it’s technically a water-methanol (methyl alcohol) mixture that injects water and methanol directly into the intake manifold.

And yes, we’re not going crazy - you’ll be spraying a water mix into your engine, but as wrong as that sounds, you won’t need to worry!

Internal combustion engines, spraying this water/methanol mix (also known as an anti-detonant injection), cool the motor’s combustion chambers, thus providing higher compression ratios and eliminating engine detonation (or knocking.)

Methanol is an extremely high-octane fuel, and it’s impressively resistant to detonation.

With a methanol injection kit, you would have a reservoir (or tank), which holds the fluid mixture and a pump that sends the fluid to the intake manifold via a digital controller system.

Typically, the digital control system will allow you to manage when the methanol begins spraying and the quantity required during different engine cycles or boost levels.

The usual methods of setting up the controller involve tapping into the fuel injector wiring harness or splitting off the boost gauge hose on forced induction applications. On a naturally aspirated engine, it would rely on the injectors.

When injecting the mixture into the intake manifold via a nozzle, the spray is so fine that the methanol vaporizes almost immediately, transforming the combination from liquid to gas.

With this endothermic transformation taking place, it absorbs heat, decreasing the temperatures by up to 100 degrees Fahrenheit.

This cooler air makes the oxygen denser, and with more oxygen reaching each cylinder combined with increased fuel, you’ll achieve impressive horsepower gains. This air/fuel ratio will require tuning to achieve maximum benefits.

Thanks to the cooler, denser intake charge provided by the methanol injection system, engine detonation chances are significantly reduced despite increasing the engine’s power output.

With less pressure on the cylinders, cooler air temperatures, and detonation unlikely, the timing and boost will be increased, even on forced induction systems.

Thanks to these improvements, forced induction engines will experience improved spool and power gains, and your engine will essentially be getting a fresh stream-clean at the same time.

Although using water sounds like a terrible idea, you’d be amazed at how new engines with water-methanol injection kits look internally after long-term use.

Since the water is in such small quantities, it doesn’t stay in liquid form long enough to cause harm or cause corrosion to your internal engine components, with the atomized vaporization taking place almost immediately.

Not only does it not cause corrosion, but it essentially steam cleans the valves, valve seats, intake, and piston tops, by removing and reducing carbon build-up.

It’s then turned to steam, which exits via the exhaust.

Despite all the benefits, a methanol injection kit is a low-risk, low-cost way of achieving improved efficiency and performance from your engine, especially on a forced induction system where temperatures and pressures are far higher.

Although there are slight risks, as with everything, this mainly comes down to people not following the correct instructions and using excessive quantities at low RPM without optimal tuning, preventing it from burning.

Whether you’re running a high-power turbo, or supercharged setup, or a completely stock petrol or diesel engine, methanol injection can be an ideal consideration for convenient and reasonably-priced power gains.

How much does methanol injection reduce temperatures?

It won’t come as much of a surprise that this varies between naturally aspirated and forced induction engines, along with the various mixtures and current cooling upgrades used.

Typically, we would expect to see temperature reductions between 50 and 150 degrees Fahrenheit, depending on the application.

What Power Gains Will Methanol Injection Provide?

Using the Snow Performance methanol injection kit, which we’ll take a look at shortly, they’ve stated that timing can potentially be advanced more than 10 degrees, with increased boost capabilities beyond 5 psi.

With these improvements, you can expect an increase of up to 20% on forced induction applications and around 5-10% on naturally aspirated engines.

Here are some real-world examples of methanol injection power gains.

First up, there’s the SpeedAcademy S14, where they’re installing the AEM methanol injection kit with a dual map set up for street and track use.

Or if you’re using a modern engine, then this BMW F80 M3 may give you a better idea.

In case you don’t fancy watching the whole video, the M3 went from 486 hp and 499 ft/lb torque to an insane 565 hp and 630 ft/lb torque with the methanol injection addition alongside the correct tuning.

Pretty impressive, huh?

Let’s not forget that methanol injection is used in some of the most impressive builds we’ve ever witnessed, including Ken Block’s incredible Hoonicorn V2:

Is methanol injection worth it on a naturally aspirated engine?

There’s no question that the maximum benefits will come from a forced induction application, and some will argue that it’s simply not worth the time, money, and effort to install on a NA engine for the minimal gains.

Since forced induction engines typically run at far higher temperatures, this is where you’ll reap the rewards of the cooling powers provided by the methanol injection.

If you’re planning on going down the forced induction route further down the line, we would certainly consider doing so.

Admittedly, on a NA engine – we probably wouldn’t bother.

Methanol Injection Pros & Cons

It won’t come as much of a surprise that whenever cheap, convenient power gains enter the equation, there are some downsides to consider alongside the many positives of methanol injection.

Gasoline Engine Pros

  • Cooler cylinder/air charge temperatures
  • Reduced chance of engine detonation
  • Improved power (typically around 5-20% depending on application)
  • Improved boost (on forced induction applications)
  • Increased timing
  • Removes and prevents carbon build-up
  • Economical for street use
  • Improved fuel economy
  • Fantastic cost to gains ratio

Diesel Engine Pros

  • Similar power gains (typically around 10-20% depending on application)
  • Improved boost (on forced induction applications)
  • Improved fuel economy
  • Reduced EGT’s by up to 250 °F
  • Reduced emissions
  • Fantastic cost to gains ratio

Methanol Injection Cons & Considerations

There are certainly far more advantages than disadvantages when it comes to upgrading to a methanol injection setup. However, there are a few minor considerations.

Mounting the components

Some people like to keep their rides as clean and OEM as possible, but with a methanol injection kit, you will have to consider mounting a few vital essentials.

When it comes to positioning the reservoir, you’ll need to ensure that it’s located within 24 inches of the pump. You will also have to ensure that the pump is lower than the reservoir base for optimal performance due to the typical ‘pushing pump’ design.

You’ll also want to make sure that it’s as far away from the heat of the exhaust region and not likely to get affected or damaged by road debris.

Replacing the mixture

Although this isn’t a big deal, it’s certainly an inconvenience and another reason you’ll want to consider your reservoir’s location.

With a standard-sized tank (around 3-quarts), we would expect the mixture to last around the same duration as a tank of gas.

Methanol consumption in big-power applications could be much higher, in which case you may want to consider opting for one of the larger reservoir kits. As always, the higher the power, the higher the cost!

Tuning

As with any upgrades that make significant performance or air/fuel ratio changes to the engine, you’ll need to ensure that you get the engine optimally tuned once you’ve fitted your methanol injection kit.

We would always advise leaving this to the professionals, as getting it wrong could cause potentially cause severe engine damage.

Running dry

If you run out of fluid or your methanol injection kit fails once you’ve had the engine tuned, you risk potential damage since the motor is now tuned to rely on the cooling powers provided by the methanol injection.

Malfunctions

We have heard of sporadic cases where the methanol injection controller has malfunctioned, which is why we recommend installing an LED to ensure that the system is currently active, which will (hopefully) prevent it from running dry when monitored correctly.

Preparing ahead

Because of the risk of running dry, you’ll need to ensure you’ve got pre-prepared fluid to add on longer journeys.

A typical water-methanol ratio would be 50:50, and it’s recommended to use distilled water, particularly in hard-water areas, to avoid contamination. We’ll be covering more on this shortly.

Although this isn’t a big deal, if you’re planning on attending a race weekend, you’ll need to prep your methanol mixture as well as your fuel.

We don’t recommend guessing, either, as this could affect the overall performance, so try to make a habit of measuring the correct ratios efficiently.

Best Methanol Injection Kits

There are now two fantastic off-the-shelf methanol injection kits available from AEM and Snow Performance.

Although some people have carried out the upgrade themselves, the affordability and convenience of these kits make them a no-brainer, in our opinion, and they come highly recommended by many tuning enthusiasts.

AEM Methanol Injection Kit

aem v2

Our comment: We’ve seen this kit installed on several vehicles, and it comes with a control unit that features a built-in boost sensor and two control knobs.

One controls the boost pressure that the methanol injection is introduced, and the other adjusts the pressure for when it’s no longer required.

When your mixture begins running low, the control unit will warn you similarly to how a car would inform you that a fuel top-up is required.

Manufacturer description for AEM V2 Gasoline/Petrol (5 gallon): “Kits reduce air inlet temperatures and exhaust gas temperatures, allowing you to increase boost pressure and advance timing without running higher-octane fuel. It’s like getting to run 100+ octane gas for the price of Premium!“

“Water / Methanol Injection Kits use a boost-dependent, variable-flow progressive controller to determine the amount of water/methanol mixture (up to 50%) to feed into the inlet stream from the included one- or five-gallon reservoir. The controller commands a progressive 150-PSI pump that delivers the mixture, and flow adjustments at the inlet are made via three included jets designed to match most engine power requirements. The result is significant horsepower gains using pump gas-at about half the cost of Racing Fuel“

Key Features:

  • Universal kit includes everything you need for installation
  • Progressive, controller-driven 150 PSI pump
  • Five-gallon tank with integral fluid level sensor
  • Dash light for system status and low fluid warning
  • Alcohol Compatible (up to 50% in solution with water)
  • Progressive controller providing boost-dependent variable flow
  • Output provided to either decrease timing or boost if the system runs out of fluid or detects an error
  • Includes three jets to match your power requirement

Snow Performance Methanol Injection Kit

Our comment: Another popular choice with an impressive selection comes from Snow Performance, who provide their kits at an impressively low price, with kits to suit any needs, from Stage 1 to Stage 3.

Stage 1 includes an adjustable pressure switch that senses your boost level in the intake, spraying a continuous, consistent mix level.

When you move to Stage 2, this is similar to AEM’s V2 kit, which provides start and final boost settings which are adjustable via the dial knob.

With Stage 3, you have a visual display and custom adjustments allowing you to fine-tune the setup manually.

Manufacturer description for Snow Performance Stage 3 injection kit for EFI or Forced Induction: “The Snow Performance Stage 3 Boost Cooler brings true two dimensional mapped water-methanol injection delivery to your EFI (electronic fuel injected) and forced induction (turbocharged/supercharged) vehicle. The Stage 3 creates a two dimensional injection map based off boost and fuel injector pulse width to deliver a extremely accurate amount of water-methanol when the engine needs it most.“

“Bringing fuel injector pulse width into the mix allows the injection curve to be extended past specific boost points for greater range/control. Non-invasive, the Stage 3 Boost Cooler controller is designed to mount on the steering column or the dash, so no additional gauge pods need to be purchased and functions as a boost gauge, water-meth controller, and fuel system monitor all in one! Proven to reduce the air inlet temperature by up to 100 degrees and increase octane by 25 points for maximum HP and cooling“.

“It comes with an adjustable Stage 3 water-meth controller, 4an Stainless braided line, and easy to install quick-connect fittings.“

Key Features:

  • Reduce air intake temps out too 100 degrees
  • Increase octane by 25 points
  • Cleans all carbon build up out of your motor
  • New nozzle design
  • Built in boost gauge
  • Lower EGTS

Water/Methanol Mixtures & Ratios

Typically the standard ratio for distilled water to methanol would be 50:50. Still, you can also consider buying pre-mixed solutions such as the Snow Performance Boost Juice, which saves the time and effort of creating the mixture and makes it convenient when traveling.

With carburetted applications, you would typically run lower methanol (around 20-30%) not dramatically to affect the air/fuel ratio.

With EFI applications, it’s often safe to use pure water or pure ethanol depending on the tune and setup but always check your specific application.

If you’re unsure, then a 50/50 ratio is the most commonly used for up to 30 psi of boost.

How to Install a Methanol Injection System

Unsurprisingly, this will be hugely different depending on the vehicle you’re planning for the installation, but we’ve found two examples to give you some ideas.

Installing an AEM water/methanol injection system to a Nissan 240SX S14:

Installing the Snow Performance water/methanol injection system to a 1JZ-GTE MKIII Supra:

Conclusion

For those of you running forced induction applications, there are a whole array of benefits that come with installing a methanol injection system, with very few negatives.

When correctly fitted and maintained, this will not only provide impressive power gains, but it’ll also improve your fuel economy and provide self-cleaning benefits to your engine.

Whether you’re using a gasoline or diesel engine, there’s likely to be the perfect off-the-shelf kit out there for a reasonable, convenient upgrade.

For those running a non-turbocharged or supercharged, naturally aspirated engine, methanol injection isn’t likely to provide enough benefits to make the upgrade worthwhile due to the lower temperatures.

But hey, if you needed another excuse to go with a forced induction upgrade, this is the perfect opportunity to do so!

So, there we have it! We hope that we’ve covered everything you could want to know about methanol injection in this guide.

Thank you for reading our methanol injection guide.

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Photography credits

We thank the following entities for the use of their photography in this article:

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author avatar Written by Joe Terrell Drifted.com founder, motoring journalist and all-round car enthusiast. Read more about Joe and the Drifted team on our about us page.

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