Commonly Asked Alcohol Injection Questions

Commonly Asked Alcohol Injection Questions


Alternative fuel options such as alcohol injection, E85 and race fuels have always been a part of tuning your turbocharged or supercharged vehicle. Adding a Alcohol or Methanol Injection system has been another very popular way to decrease intake temperatures and increase power. Whether you are adding a new SNOW or AEM injection kit, upgrading boss sizes or changing your injection mix, there’s no doubt you’ll have some questions.

One of the more commonly asked alcohol injection questions is of course; “What is Alcohol Injection?”. Alcohol injection or water injection has always been one method of lowering intake temperatures, especially in force fed applications. It’s uses and benefits vary but not only can this technology generate horsepower reliably, it can also clean your combustion chambers, de-carbonizing pistons and valves.


That’s what our top 10 commonly asked FAQ is here for, some of the most commonly asked alcohol injection questions we get here at Pro Street. If you’d like your question asked or answered here on this form, please submit it using our contact form or How To submission form.

AEM’s new Injection kits are highly developed horsepower generating units.


Q : Will the use of alcohol injection damage my engine?

A : The mere act of bolting on a alcohol injection kit will not decrease your engine’s reliability. If your engine can handle a set amount of boost and horsepower reliably, simply adding a water or alcohol injection kit only increases power and reliability. This changes the second you decide to up your boost, or lean out your fuel curve with the use of water or alcohol injection however.

Because this is an added fuel to your system, you run the danger of running out of alcohol / water / methanol during the middle of a run or pass. This could lead to disastrous effect the closer you are to detonation with the kit installed. Make sure to check out our primers on how to dyno tune your vehicle, as well as how to tune closed loop operation for more details.

Some earlier kits had some serious problems


Deterioration of your water injection kit can also lead to dangerous conditions in your vehicle. Always check the condition of your water or alcohol pump, to ensure that flow is optimal and that no failure can occur.

Q: How Do I tune my Alcohol Injection Kit?

A: You’d be best served checking out our How To’s on tuning your vehicle, closed loop as well as tuning on a dyno to learn the basics. However when your vehicle is equipped with knock sensors, this makes the job easier. Watching knock counts during a pull is the easiest way to shape your fuel trim to your liking.

How To Program a Fail Safe UEGO
How To Program a Fail Safe UEGO

You will be increasing boost pressures, and taking away fuel, all while watching for knock counts to rise.  Make sure that you are not running dangerous levels of ignition timing, which could erase the margin of safety you have to tune with. Monitor your knock counts while tuning engine performance levels so they are not compromised by an excessive amount of spray.

Q: Do I need to upgrade my intercooler to match the injection system?

A: Typically no, because the act of bolting on a injection kit is lowering your intake temperatures, which is what your intercooler does. Because your intercooler lowers intake charge temps by passing the charge through an air to air heat exchanger, a larger core is usually not needed.

Q: How much ignition timing can I run?

A: This will vary depending on your setup and how much knock you are encountering. Make sure to always start low and add timing as you go along, to prevent any catastrophic accidents. The more ignition timing you are running however, the less safety window you’re operating with. Add too much and you’ll wonder why your pistons melted and ring lands broke when your Exhaust gas temperatures and knock counts looked good.

Ignition Timing vs Cam Gear Timing


Remember that we’re talking about ignition timing, not valve timing. If you have a question about cam gear timing or valve timing, and how to tune it, check our guide here.

Q: What’s the benefit of alcohol or methanol vs water?

A: A great question and one that’s debated at length both on the Internet forums as well as our own garage. Fans of water injection will go on about the relative benefits of cost and operation in water, being both cleaner and cheaper alternatives.

Proponents of alcohol and methanol often point to the power producing capabilities and the combustion factor of alcohol. While both offer detonation control while lowering intake temperatures, only alcohol produces more power and more results with less injection.

Q: Will alcohol or methanol damage my engine?

A: While these chemicals left alone in engine parts will damage them, spraying a fine mist and atomizing your intake charge will cause no damage. You will however need to keep a careful eye on your pump, lines and nozzles to ensure proper operation and atomization.

Setups like this top mount B16 gain over 65 whp using alcohol injection.

Q: What kind of alcohol should I use and where do I buy it?

A: You can use any kind of alcohol so long as it doesn’t contain sugar. Denatured alcohol can be found in paint stores or paint thinner, isopropyl alcohol is rubbing alcohol and sold in many pharmacies and methanol can be purchased at any local race gas supplier.

Q: Can I use alcohol injection on the street?

A: Easily one of the more commonly asked alcohol injection questions, the legal answer to this question is no. Alcohol injection and water injection kits are usually not CARB legal, and not for use on public highways. If your vehicle happens to “share” street duty as well as race track duty, might we suggest a mix of water and alcohol, which makes the mixture non-flammable.

Q: What tips can I follow to maximize my alcohol injection experience?


There’s a few features we’d like to go over as part of our commonly asked alcohol injection questions guide. Most of which detail the kind of advanced features that you may want to look for in an injection kit.

Variable triggers – Being able to adjust when your injection kit kicks into action is a big plus. With boost or rpm selectable inputs, you can vary how you want your alcohol or water injection delivered. Most turbocharged applications will use the boost or MAP sensor to trigger the injection system, and can also ‘ramp-up’ to meet demand.

Have a static compressor driven supercharger system that reaches full boost by redline? Or maybe your engine is high compression and you’re using the injection to take the edge off? Use the RPM activation trigger to maximize performance and gas mileage.

Primer pump – Many kits simply instruct you to install your injection pump ABOVE your nozzle mounting location, to make sure that there’s always fluid in the line. Needless to say, if your application is limited for space in the engine bay or you have a mid mounted engine or rear mounted engine setup, you will want a primer pump that’s seperate from your delivery pump.

This primer ensures you have a full line at all times, and that you won’t run the risk of running lean if the line is empty.

Injection Overrun – This feature is found on many of the newer kits, which basically shuts down the system if there’s an error or nozzle failure. This prevents too much water or alcohol from entering the engine and potentially damaging it.

Injection Ramp up – Nifty feature that not all kits employ, but we wish would be included in each and every injection kit. Being able to ramp up your injection delivery gives you the ability to customize the pressure to match the engine output.

Many injection systems use a progressive increase, which can cause problems if the voltage at your water or alcohol pump is too high for the boost in question.

That does it for our commonly asked alcohol injection questions guide, if you have any questions about alcohol injection, about how to tune it or want a question added, please let us know below!