Water Methanol Injection 101

Preface
OK, so my own perception could be slightly biased, however it seems to me that there is a growing interest in W/M injection for TDI's. As such, I figured I may as well start a thread designed to be a somewhat comprehensive one-stop-shop for everything you could want to know about this relatively unique performance upgrade.
For the purposes of this thread, I’m basically compiling all the knowledge I have learned both from the web and from personal experience. I’m not posting my sources because A) I’m lazy, B) I might not remember where specifically I got some web-based information, and C) Google is a thing; you can use that to corroborate stuff here if it makes you feel better. Speaking of which, if I’ve posted incorrect information, please let me know so I can make it right.
I would like this to expand into a discussion, and perhaps become a place where those of us with W/M can share experiences and maybe learn from each other’s work, while giving others who may be considering W/M a chance to learn from our collective know-how. For me, I’m using a SnowPerformance W/M kit with a 2012 MKVI TDI Golf (That’s VW’s CR140 engine to be technical). If you’re using a different setup or engine, please don’t be shy! Tell us about it!

Disclaimer:
I am NOT a mechanic, technician, or VW engineer; I’m just a guy with a passion for cars, and VAG cars in particular. Performance tuning, for me, is a hobby for which I have professionals perform the work (at least for now). I do not encourage anyone to perform any modifications to their vehicles without first having done enough independent research to feel confidently informed about all of the pro’s, con’s, and ramifications of said upgrade(s).

Anyway, enough of that stuff. Let’s get to it!

Think of this post as a sort of table of contents. Just click the links to bring you to each section.


What is Water Methanol Injection?
http://www.golfmk6.com/forums/showpost.php?p=1283468&postcount=2

What does that do? Injecting water into an engine sounds like a bad idea…
http://www.golfmk6.com/forums/showpost.php?p=1283485&postcount=3

OK that’s cool and all, but you’re talking about a gasoline engine there. What about diesels?
http://www.golfmk6.com/forums/showpost.php?p=1283490&postcount=4

So, is it worth it?
http://www.golfmk6.com/forums/showpost.php?p=1283495&postcount=5

OK, I'm convinced! Is there anything else I should know about using W/M in my TDI?
http://www.golfmk6.com/forums/showpost.php?p=1283537&postcount=6



Hope this has been thoroughly informative and helpful!

What is Water Methanol Injection?

W/M injection is where spray nozzles are installed on the intake manifold of a forced-induction (turbocharged or supercharged) internal combustion engine. These nozzles spray a fine mist of some ratio of water and methanol into the pressurized air going into the motor. Basically, W/M injection is a type of chemical intercooling.

What does that do? Injecting water into an engine sounds like a bad idea…

I know, that’s what I thought too, but it’s not. Time for a little history lesson!

Believe it or not, the notion of injecting water into an internal combustion engine (both gasoline and diesel) is nothing new. Fighter pilots during WWII injected water into their engines as a means of synthetically raising the effective octane rating of the fuel. Doing this allowed for higher compression ratios, better thermodynamic efficiency, and therefore significantly higher power. During the course of its development, the popular Rolls Royce Merlin V12 engine used in the American P51 Mustang and the wonderfully famous British Spitfire, went from pitiful (for a 27l engine!) sub 1000HP numbers to over 2,500HP (Holy $!!!) towards the end of its development with water injection. The strangest/coolest thing about it was that despite the higher compression ratios, forced-induction boost pressures, and the enormously increased power outputs, the engines themselves became more reliable as well because they had lower overall operating temperatures.

That's good. Lower temps mean less thermal stress on critical engine components, and therefore higher reliability.

So, to sum up what W/M does for an engine, it:
Keeps your engine clean and healthy (Carbon build up? What carbon build up?)
Improves the thermodynamic efficiency of the combustion process, which equates to:
Reduced emissions
Reduced thermal stress
More power
More torque
Better MPG (I believe Snow Performance's MPG gains are a little inflated, but personally I've noticed an improvement of at least 1 or 2, maybe more, MPG on average)

That’s cool, but you’re talking about a gasoline engine there. What about diesels?

It takes a little time to fully explain W/M injection in the context of a (modern) diesel engine, so bear with me if you can; if not, I understand. I did say this was thorough didn’t I? For this explanation, I try my best to go into detail on what happens during each stage of the diesel cycle.

Intake:
For starters, methanol is miscible in water. This means that they become chemically homogeneous via an exothermic reaction (produces its own heat when they mix). This dramatically affects the evaporative qualities of the water, so that it not only freezes at lower temperatures, but also evaporates into a gas at lower temperatures as well. We want this during the intake, because it means that when the W/M mixture is sprayed into the charged air stream (post intercooler), the charge air temperatures will drop even further as the fine mist absorbs even more heat and becomes more gaseous. Cooler charged intake means a denser charge, and thus more stored potential energy.

Compression:
It's important to remember that the auto-ignition point for most diesel fuel is somewhere in the neighborhood of 210° C. Already that's more than twice the temperature (at sea level) for water to become steam. As the temperature and pressure of the compression rises, the W/M will remain suspended in the charged air without auto-igniting because it has a much higher auto-ignition threshold than the diesel fuel. The compression temps and pressures won't be much different than just straight air, but with the W/M, much more of that thermal energy will be stored in the water vapor than in air molecules, because water has a VERY high heat density compared to other compounds. This is good, because it means that there's more heat being absorbed by the water (which can be exhausted) than there is heat being absorbed by the engine itself (like the cylinder side walls, pistons, heads, valves, etc.), which can't be exhausted.

Ignition:
In a lot of modern diesel engines, especially in our TDI's, it's not uncommon for there to be multiple, and very precise, fuel injection occurrences. Usually there's a small pre-injection just before the piston reaches TDC (top of the compression stroke). This is done in order to rapidly raise temperatures and pressures right before the main injection at TDC. This is where things get really interesting in the case of W/M. Due to the fact that the methanol ignites faster than the diesel fuel does (which tries to push the piston faster during the power stroke, and thus gives you more power), the pre-ignition fuel injection will cause energy levels to rise even further, while the water will keep temps in check by absorbing that additional energy without yet completely vaporizing. Even though temperatures are now well above water's normal boiling point, the enormous pressure will keep some microscopic water droplets from vaporizing yet. *I'm not entirely sure if the water at this point in the process becomes a supercritical fluid or not, but wouldn't surprise me if it did briefly.
So, now when the main power injection happens, the fuel is going to be injected into much higher energy dense conditions, which allows it to combust more efficiently and completely. As we pass TDC, and the piston moves back down for the power stroke, any microscopic water droplets that couldn't vaporize before, due to the enormous pressures, will now become a very hot and very dry steam as temperatures rise (from the fuel combustion) and pressures fall (from the piston moving down). This steam expands very quickly and with a LOT of force, which in turn provides additional torque. If you don't think vaporizing water has much "oomph" behind it, I suggest you go make some popcorn for your observation (and consumption).

Exhaust:
Due to the fact that more heat from the combustion process is absorbed by the water than by the engine itself, that heat is therefore more efficiently taken out of the engine when all that steam is vented out during the exhaust stroke. This does mean that you may see slightly higher EGT's (exhaust gas temperatures) but nothing harmful or dangerous. The EGT's are higher because your engine is more efficiently burning its fuel, as well as exhausting the heat from that process, not necessarily because the combustion itself is hotter. This isn't necessarily a bad thing either, especially when you consider that the DPF can now work better as well. The DPF has more heat with which to burn away excess particulate matter, which is how it works.

Bonus effects:
One of the biggest issues that has plagued direct injection engines, both diesel and gasoline, is carbon build-up on the intake valves. The reason for this is due to the fact that there's normally a small bit of overlap between the exhaust stroke and the next intake stroke with relation to which valves are open or not. In other words, there are times when BOTH the intake and the exhaust valves are (partly) open at the same time while the remaining exhaust gasses are still going out and the new intake gases are coming in. OK, so what? Why does carbon build up on the intake valves and not the exhaust valves? Temperature. The exhaust valves are going to be much hotter than the intake valves, so any carbon that would build up, usually gets burned off. That's not the case for the intake valves however. Carbon will build up, but it never gets hot enough for it to be burned off naturally.

Before the advent of direct injection, the intake valves usually had some kind of direct contact with unburned fuel as it went into the combustion chamber. That unburned fuel has a cleaning effect on carbon deposits, which normally keeps carbon build-up in check. With direct injection, that is no longer the case, as fuel is injected directly into the combustion chamber, and so you lose that cleaning effect. With W/M, that cleaning effect is reintroduced, and the carbon build-up issues are mitigated. Think of it like getting your engine steam-cleaned every time you drive it!

So, is it worth it?

That's really up to you in the end. I got mine installed for about $1,500 US including the cost of the kit and the labour for installing it. When you consider that it can easily cost that much (or more!) to have someone take apart the top of your engine to wire-brush, scrub, and clean out all that nasty carbon build-up, yeah, I'd say it was money well spent. At the time of this posting I've put about 9k miles on my car since I had it installed, and I have had zero issues with it whatsoever. Suffice to say, I'm very happy with it!

Update: 26k miles now, and the engine is happy as can be!

OK, I'm convinced! Is there anything else I should know about using W/M in my TDI?

Sure there is! That's the point of the rest of this thread. There's only so much that can be had from reading spec sheets and understanding the technical ins and outs of the technology. From here on out, I'd like this to turn into a community discussion on our own real-world experiences with W/M injection so that we can all benefit from each other and get the most out of this tech. I'll kick it off with some of my own personal experiences and lessons learned:


Having a well mapped injection profile is CRITICAL.
The SnowPerformance kit (depending on which options are available with the one you buy) can have its injection profile mapped to either boost pressure or EGT's. I prefer mapping to boost pressure because it is much faster reacting and better suited to the dynamic driving behaviour common on public roads.


Don't inject too much too soon, or you'll get bad quench and knock.
When you're first starting out with your W/M kit, be very conservative with your injection timing. In other words, start with mild amounts of injection at higher boost pressures, and then gradually work your way down to lower pressure injection timing until you find the best settings for your driving style. For example, I currently have mine set up such that max PSI is defined as 26, low pressure injector nozzle ramps up starting at 12 PSI, and the high pressure injector nozzle kicks in at about 17 PSI.

Ideally, you'll want to calibrate the injection such that the majority of your normal/light driving can be done without any injection at all (pretty easy to do, while keeping the boost gauge below the 12 PSI mark), and only have it kick in when you are under moderate to heavy throttle or load (like when passing or going up an on-ramp).


SnowPerformance's performance gains are inflated.
This is not to say that there aren't performance gains to be had at all, especially of you have other performance upgrades planned. If you've already got an ECU tune, like a stage 1 or 2, then W/M can be a very nice supplemental upgrade before something bigger like an upgraded turbo (which the W/M will compliment VERY nicely as well!). I'm currently running my system next to an APR stage 1 tune, and though I'm not entirely sure how much extra power the W/M is giving me, it is enough to notice a difference; conservatively, I would estimate I'm getting about +10WHP and about +20WTQ from the W/M. However I wouldn't recommend it if you're still running a stock setup, which leads me to the next point.


Don't expect the W/M system to blow you away with extra performance, especially if you're running stock tune and/or using a ~70/~30 mix (AKA washer fluid):
Even if you're not expecting huge performance gains, W/M can still be worth installing if you're looking to improve your fuel economy (mine has improved by at least 2 or 3 MPG on average over the last 7 or 8k miles I've had the system), or just as a preventative-maintenance measure to help reduce carbon deposit build-up. If that's the case, then washer fluid is a more-than-reasonable economy option. However, if you're really serious about getting performance out of your kit, 50/50 water-meth is the only way to go, and mixing it at home is the cheapest way to do it. I buy 5 US Gallon drums of pure/neat methanol (without added lubricant) from a local racing fuel company in my state, and then just mix with distilled water from CVS. 1 drum usually sets me back about $80 - 90 incl. shipping, and it lasts me about a month (I go through W/M about 2.5 US gallons a week on average).


Don't run your system on a cold engine!
It should seem like common sense, but it's important not to get lazy about your W/M system. If your kit comes with a master cut-off toggle switch, then use it. If not, get a toggle switch and then use it. Don't turn on your W/M until the engine has had time to warm up to normal operating temperatures. If you're just running out and back for 5 minutes on a cold engine, it's better just to leave the system off.


Turn off your W/M system at LEAST 2 minutes before turning off your car!
Depending on how much the W/M system is being used during operation, your charged air intake may still contain enough latent moisture that it will condense when your engine cools down. If this happens, it may make for a more difficult cold start. Don't worry though, because this can be prevented by making sure the intake has had enough time to purge the entire manifold of any remaining moisture. 2 to 5 minutes of normal driving, without the W/M system turned on, should do the trick.


Where can I get W/M?
Lot's of places actually. One of the easiest, cheapest, and most convenient ways to get it is just to use cheap washer fluid. Specifically you'll want to find the stuff that's rated for -20°F, which normally is ~70% water and ~30% methanol. DON'T use any of the more expensive formulated stuff like bug remover, or deep freeze stuff though! Those other formulas usually contain a bunch of other ingredients which you're not going to want to put into your engine, like propylene glycol, which can gum up your W/M injectors and mess up the pump!

The most reliable way to ensure only water and only methanol is going into the system is to mix your own; that's what I do. Pure methanol (specifically neat methanol, without additives or lubricants) can be sourced from most racing fuel distributors or other chemical suppliers. An ~$80 5 gallon drum is more than enough to last a month or so of normal/moderately aggressive driving. Distilled water can be found in just about any pharmacy or grocery store. It MUST be distilled, or you'll get mineral deposits!


Above all, water/methanol is tricky business, so be patient.
As I talked about above, regarding your injection profile, take your time with it. Don't be afraid to tweak the settings and experiment a little. Try different water/methanol ratio's; see what works. See what doesn't. A richer mix (more methanol content) will give you more power at the expense of higher EGT's. A leaner mix (less methanol content) won't give you as much extra power, but your EGT's will stay much lower. I don't recommend methanol content that exceeds 50% BTW, that just gets way too risky for my comfort zone. Everyone's car is different, and everyone's driving style is different. Take the time to really figure out what kind of setup works best for you, and smile as your reap the rewards.


Don't mind the CEL!
It should be noted, however, that over time you may notice your car occasionally belch out some burned carbon, especially during a hard pull after the DPF/EGR system has performed a regen cycle. This is normal behaviour, and not something to be concerned about. The smoke/carbon ash should be a pale dark grey colour. Not white or slightly blue. Also, due to the fact that you'll be flowing more carbon deposits through the exhaust (as opposed to letting those same carbon deposits build up inside your engine), you'll eventually overwhelm the EGR valve. The EGR is an EPA mandated system that functions by recirculating a portion of the exhaust gasses back into the intake of the engine, and essentially double-burning it. This system does nothing to aid the function of your engine, and in fact improves your performance and mileage when blocked off (seriously, there is such a thing as an EGR block-off plate). However, when your EGR inevitably does become overwhelmed (I.E. completely blocked off from the carbon build up), you will get a CEL (check engine light). The error code should be P0401 "EGR insufficient flow." *This is nothing to be concerned about, apart from the minor annoyance of having a CEL on. I just use a cheap bluetooth OBDII adapter and the Torque app to check and clear the error code when it shows up. No biggie.

*Recently confirmed from a VW technician at my local dealership.

No one has replied to this yet but I just want to thank you for the interesting post! I'll be following this as more people with experience chime in.

Thanks :thumbsup:

I've ridden in Wolf's car and you can most definitely feel the difference with W/M kicking in.

I plan to do this mod as well; just a matter of money :thumbsup:

So, with the Butt Dyno telling you that you can feel the Power (wow bad pun, LOL), is there any additional mods on Wolf's car or is this car stock besides the W/M injection?

Wolf, Great Write up, my eyes are hurting from staring at the screen for so long reading this excellent article!

I'm sure he'll answer up, but I can tell you he has APR stage I and the W/M injection kit. I don't think he had any other power mods but can't swear to it.

He started out with the W/M off, car seemed a little faster than my stock one (APR) but nothing major or exciting. But once he turned on W/M and hit the boost levels it really kicks you back into the seat.

VR6Growl is correct. So far, the only power upgrades I have performed are the APR Stg. 1 and the W/M. Otherwise the car is bone stock... until July 25th!! That's when I'm having a lighter flywheel, stronger clutch, and front LSD installed. Next after that are wheels and brakes, then suspension.

Wolf, when you do all that, you need to go Rawtek on the Exhaust, and Malone Stage 2 and dump the apr tune. Then let us know how it is! I wish I had the money, after reading all this, a Meth/Water injection is on my list along with Malone Stage 1.5 Tune

85RedGolf2.5 said:

Wolf, when you do all that, you need to go Rawtek on the Exhaust, and Malone Stage 2 and dump the apr tune. Then let us know how it is! I wish I had the money, after reading all this, a Meth/Water injection is on my list along with Malone Stage 1.5 Tune

Click to expand...

I've been considering going this route, because the ~24 - ~26 PSI that you get with APR, although cool and all, and a definite improvement from stock, does feel a little bit lacking on the top end with the W/M as part of the equasion; it feels like there's WAY more potential to be had if I were pushing say, 36+ PSI instead.

That said, the good folks at NGP Racing in Lorton VA are currently performing an experimental adaptation of a UK-based turbo upgrade used on the Euro-spec CR140's on the other side of the pond. Supposedly this new turbo, in conjunction with some custom Malone tuning software, and totally re-worked manifold-back piping (3.5" turbo-back!!!!) should push north of 400 ft\lbs of torque (and that's WITHOUT the W/M!). Not sure what the HP numbers are, but it sounds like a sick (and VERY expensive!) upgrade. The only hold-up I could think of that might discourage me from doing this one is the fact that VA has tighter emissions requirements that I may not be able to squeeze past, seeing as how this upgrade deletes both the EGR and the DPF (not that those are bad things to drop from a performance standpoint)... Plus there's the whole thing about that being technically illegal at a federal level for use on public roads...

So maybe I'll skip the Malone Stage 2 for now, and instead focus on brakes, wheels, suspension, interior/exterior aesthetics, and THEN do that. We'll see! Suffice to say, the APR stage 1 + W/M is "plenty good" for the time being. By the time I'm ready to do that big turbo, my warranty will have probably expired anyway; then I can go nuts! Then again, the only hold-up I could think of that might discourage me from doing this one is the fact that VA has tighter emissions requirements that I may not be able to squeeze past, seeing as how this upgrade deletes both the EGR and the DPF (not that those are bad things to drop from a performance standpoint)... Plus there's the whole thing about that being technically illegal at a federal level for use on public roads... :thumbdown:

I'm in the same boat. Va sucks and more so up here because of the increased police...

It's a bit annoying when my friend is modding his GTI and I (we) cant get around anything with the mk6 TDIs :/

Yay for better MPG but damn I wish we could draw more power out of this car!

changingtide said:

I'm in the same boat. Va sucks and more so up here because of the increased police...

It's a bit annoying when my friend is modding his GTI and I (we) cant get around anything with the mk6 TDIs :/

Yay for better MPG but damn I wish we could draw more power out of this car!

Click to expand...

VA regulations has me seriously considering making a move to MD. I work in DC anyway, so it's not like it would be all THAT inconvenient...

P.S. Are you a member of NOVA DUB's?