[Davenow]

Since I am not a prick anymore

*AS OF 7/11/08 THIS IS A BIT OUT OF DATE, SOME THINGS HAVE CHANGED, SOME NEW KITS, SOME NEW FINDINGS ETC. I AM WORKING ON UPDATING IT. I HAVE ADDED/CHANGED A COUPLE SMALL DETAILS, BUT I AM NOWHERE NEAR DONE. OVERALL ITS STILL GOOD*



NOTE* This FAQ is very SMC and Subaru specific, as this is what I know. But it mostly applies to all cars/setups

What does alcohol injection do? It injects a mist of alcohol directly into the intake stream, this has the effect of massive "chemical intercooling" along with greatly raising the octane level of the air/fuel charge. On 93 octane pump gas, the general concensus is that when the system is spraying, you are at or around 110 octane

So what does that do for my car? Well higher octane and a MUCH cooler air charge means a MUCH higher detonation threshold. It will take a LOT more to make your car knock

My car isnt knocking now, why do I care? Because one spot of bad gas can make it happen. And where "stage 2" wrx's last forever, there have been quite a few "stage 2" STIs blow up. You want as little chance to detonate as possible. With alcohol injection, its probably about 100 times less likely to detonate. And if you dont tune super agressively, you can pretty much set the car up to where its almost impossible to cause it to knock in any driving condition, with any weather change

What Benefits are there other than the above? POWER. You can tune leaner, running up to 12-1 under full boost. I run 11.7-1 at 19lbs and never see det. Your EGTS typically go down up to 200 degrees too. Mine are about 75 deg lower than pre alch. You can also run up to 5 degrees more timing and 2-4 more lbs of boost. Want detonation free 21lbs of daily driving boost on a stock STI turbo? You got it. It will be hard on the turbo, but those are cheap enough
Typically I would say running 2 more psi boost, 20% less fuel under boost and 3-4 more degrees timing would be a "normal" alcohol injection tune.
It also has the effect of "steam cleaning" the engine from the throttle body to the exh ports. No carbon buildup on the backs of your intake valves, and the domes of your pistons stay MUCh cleaner. Which means MUCh less chance of "hot spots" which cause detonation

But that sounds expensive to run Alcohol, in 1 gallon cans is about 7-11 dollars per can.

wow thats nuts, how long does 1 gallon last? Well the SMC kit uses your washer bottle, thats 1 gallon. Most people get 2 to 3 tanks of gas out of 1 fillup. I average about 2 1/2 tanks of gas for each alcohol fillup.
When you are tuning your car, it will go MUCH faster as you are spraying a lot more often. At a track day, it will REALLY go fast. I havent done a track day with it yet, but I would suggest you plan on AT LEAST 1 tank per session. If you use a 1 gallon tank, it MAY not even last the entire 20 min run session, or it might, you would have to talk to someone that has run it at a trackday. Best bet, if you are going to try it, is have EM that you can switch maps on the fly. That way if it runs low (watch for the light) you can switch to a non alch injection map on the fly. It may not be an issue, I have no honest idea. If you run a bigger tank, you shouldnt have a problem. If you are going to do a lot of track days and want to run this, you should consider buying the 12L Spec C tank and using that as your tank. SMC will install the pump in that for you if you would like

Can I mix the alcohol with anything to stretch my dollar?? YES!! Many, in fact, in the subaru world, most ppl run a 50/50 mix of distilled water and alcohol. The difference in what the alcohol injection does for your car is small. FIgure if straight alch would yeild you a 110octane charge, figure 50/50 would net you 108ish. I am totally talking off the top of my head, but I use those numbers to illustrate how small the difference is.
Also, if you mix, you end up with 2 gallons of mix. Which means for about $13 max, you get 4-6 tanks of gas worth of alc injecting goodness. That drastically lowers the cost to run this

What kind of alcohol?? WHere do I get it? Home Depot is one of the most common places people get it. The type is "Denatured Alcohol". Rubbing alcohol can be used too! If you are tuned for denatured, and you cant find any for some reason, you can stop at any grocery store, or drug store, and buy rubbing alch, dump it in, fill that bottle with water, and dump that in. I did that just the other day, it worked great

What about Methanol? Works great. Tune will be SLIGHTLY different than denatured
* Methanol might be harder on the seals in the pump than Denatured, so before running it you should check with SMC (or whoever's kit you choose) to be sure their pump and such will be ok with it. I will email SMC and ask about it and update this as soon as I hear back from them

Doesnt alcohol eat rubber? Yes a little, but that doesnt matter as this never touches any rubber

Alcohol is flamable, will my car catch on fire?? If its straight alcohol, and you get hit hard enough to puncture the container, yes it could. But at that point, sorry to say but your car is most likely totalled anyway. The fire will just prevent the insurance company from trying to fix it and leaving you stuck with a car that has been in a BAD wreck and was repaired. If you run a 50/50 mix, it will not catch fire as the 50/50 mix does ignite. At least when several of us have tried to ignite it, it just will not light, so if you run 50/50 you are 99.99999999% safe

So is this dangerous for my motor?? Well if you are boosting hard, and it fails, there is a very high chance your motor will blow. However, this is ULTRA rare, in fact I have yet to ever hear of a single case where it has failed and the motor was lost. I know it HAS happened, but so far, not in the subaru world, and from what I have heard and read, the cases where it failed, were bad installs. One guy with a VERY early SMC kit had a pump go bad, but his motor was fine

So how does this work?? Ok So, you have a few parts. This is standard with all the kits, some have a couple differences, but here are the basic parts.
Tank
Pump
Controller
Nozzle
Some kits have a single stage or dual stage controller that sprays at either a constant flow rate regardless of boost pressure, or sprays at a higher rate after a given boost pressure.
Yet other kits, such as the SMC kit or the Devils own kit use a progressive controller. This is by far superior. It starts spraying at a predetermined boost pressure, that YOU can set and ramps up to maximum spray at another, higher predetermined boost pressure that YOU set. The SMC kit, and I THINK the devils own kit come set to kick on at 7PSI, and max out by 15 PSI. This doesnt mean it doesnt spray past 15PSI< it means it is a constant rate past 15 PSI. And you could make it 20PSi if you wanted to, you arent limited to 15PSI, thats just the default.
Some people set it to only kick on at say 15 PSI or so, which saves a TON of juice, but you lose all the benefits of lower boost spray. 7PSI is great because then it will JUSt kick on when you are at part throttle boost.

More details please! (the info here is based on a progressive controller) Ok so you are cruising along, you hit the gas, you hit 7PSI and the spray control unit kicks on. It turns on a high pressure pump that sends the mix down a hose to the nozzle which is typically located 2-3 inches in front of your throttle body. TMIC people usually drill a hole in the bottom front of their tmic and put the nozzle there. FMIC guys typically put it in the pipe, again, 2-3 inches in front of the throttle body.
As boost increases, the pressure from the pump increases, which causes more to be sprayed into the intake stream, up to the max point (default is about 15PSI)
IF YOU DO NOT HAVE A KIT WITH A PROGRESSIVE CONTROLLER> It will begin spraying at a constant rate at whatever boost pressure it is set to, many times this is not adjustable and is determined by what pressure switch it uses. This kind of kit still works, but it isnt nearly as nice and not nearly as tunable as one with a progressive kit. I would recommend staying away from these, and at least getting a kit with 2 stages. However if you are just going to have it spray at or about your max boost, this kit should be fine. However be aware that there is a good possibility of a "hesitation" like feeling at the point that it kicks in, no matter how much you tune.



I live where they only have 91 octane, will this help me out?? In those cases, you are helped out EVEN MORE than the 93 octane people. You will have a lower overall effective octane, but it will still be well above the equivalent of 100 octane. Your power and detonation resistance gains will be more dramatic than the people who can get 93.

So this is like running race gas? Yes and no. Its better than 100 octane(and MUCH cheaper) but its no C16 (which is 116 octane) Its a heck of a lot more economical, because lets face it, you dont need high octane when you are cruising around off boost, or even at 1-4 PSI boost. Heck I drove my WRX around on 89 octane and wastegate boost with no issues for awhile just to test that theory. Think of this as race gas when you NEED it, and cheap pump gas when you dont.

Do I need engine management to run this? Yes, 100% absolutely you HAVE TO have, at a minimum, some way of tuning fuel. Because when this sprays you will go INSANELY rich, like 7-1 rich. That is rich enough to be dangerous and can cause bore wash (this is where there is so much fluid in the cyl that it rinses the oil off the cyl walls, and the rings tear themselves and the cyl wall up.)

I dont want a ton of power, I just want the safest car possible Then leave it stock. There are no absolutes and ANYTHING you do to the motor increases the chances of it blowing up.
HOWEVER, you can make your car a LOT safer than it would have been. If you are considering this as a precautionary mod only, you can leave the timing and boost alone, and only tune to a "normal" a/f ratio as if it didnt have alch injection. Note than a "normal" non alch a/f is richer than what is considered a "normal" alch injection a/f, at least a little(in most cases).

I want m@d p0w3r y0! Great! Some have been able to go as agressive as: 3 more PSI, 5 more degrees timing, and 12.5-1 a/f without detonation and safe EGTS!!!!!!!! That is not the common setup though. Most knowledgeable people will recommend something around this : 2-3 more PSI boost, 3-4 more degrees timing, depending what your car will take without det, and a/f's around 11.7-1. On a "stage 2" (Em and turboback) STI, gains are typically around 20-25whp and 25+ft/lbs of torque. Combine 20whp, 25ft/lbs of tq and a safer running car, and you can start to see why this is such a great mod.

I have never heard of this, I am suspect of something this new Its not new at all. The turbo buick guys have been running this for probably 15+ years. Other racing cars have run this going back past the 60's. Rest assured, this isnt something "new"

The SMC kit is nice, but I want something more "stealth" that you cant see easily under the hood Then something like the Cooling Mist or Snow, Or now, the AEM kit or some of the other "build it yourself" kits would be your ticket. These kits are just as complete, but are more labor intensive. Once installed and adjusted, they do the same thing. Of these types, the "Aquamist" is probably the best, but its VERY expensive and you dont really get a lot more functionality for the money IMHO. However Aquamist has a VERY good name for a reason. VERY high quality parts. Does this mean that the $300-500 kits are worse quality? Not typically.

I have an STI with Em and a turboback and I am maxing my injectors duty cycle at 100%, will this help me?
Absolutely. At 19PSI I am only seeing a max injector duty cycle in the mid 70%'s with my alch injection.

I want to go for some kind of stock turbo record, will this allow me to "safely" run really high boost??
You could run 23PSI easily, if not 25PSI, on pump gas, with alch injection. I have a buddy running 23PSI on his TD04 on his WRX with alch injection. He just trapped 105.5mph with that setup. Pump gas, 2.0l WRX, TD04, alch injection.

I am not very mechanically proficient, which kit is easiest to install? SMC by far. It typically takes about 1 hour to unpack, install and get up and running. Why? Because of how it is setup. The kit comes with a washer bottle with the pump assembly already installed. Yes, you get a replacement, smaller washer fluid bottle so you retain your ability to wash your windshield.

Can we use the intercooler spray tank in the trunk? Yes. SMC will install the pump in it if you send it to him. If you are using one of the other kits, you can install it anywhere you like as well. Any of the individual part kits can use it as well (IE the Snow or AEM)

How much are these kits? $249 to $1000+ The SMC is 499, the Devil's Own is like 349, the coolingmist has an option for 249 I believe, and the top of the line Aquamist is over a grand IIRC.

My methanol setup looks like it is set to come on at like 5psi and end at 15psi. Do you know why this may be happening? I'd think it'd be like on at 5 and end at 30 or something. Is there enough methanol to go around by the time 15psi comes and thats why it shuts off
The default is generally 7ish to 15ish
This means it maxes flow at 15PSI, not that it stops spraying (you probably knew that). Once it is spraying at full volume it is flowing a good bit. 15PSI is a lot of pressure, even if your max boost is 28PSI, so you want it to get to full spray by then. You dont really want it at full spray lower than that because it doesnt NEED that much of a boost in octane lower than that. Past 15PSi you want as much of a boost in octane/cooling as it can give. Which is why peak spray is set at 15PSI.
If you set it higher, you essentially take the ramp up rate, and make it longer/slower. If 7 and 15 means a 45 degree angle, 7 and 30 PSI would be like a 30 degree angle. Get what I am saying?
I ended up actually making mine come on a bit sooner, so it starts spraying at about 5.5PSI
The low number is when it STARTS to spray. The higher number is when it reaches maximum flow, it does NOT stop spraying at that number.

My car didnt come with a turbo but I added one (like a turbo'd honda/acura) I wonder if this could help me?
Absolutely! Cars that didnt come with forced induction have higher compression motors than cars that came with a turbo/supercharger. Higher compression brings in a higher chance of detonation. And since a cooler air charge, and higher octane means more resistance to detonation, you would surely benefit from alcohol injection, possibly more than cars that came with a turbo from the factory.
Think of it this way.
How much boost can a civic/whatever with a turbo handle with NO intercooler? How much more power can you make WITH a nice FMIC on that same car? Alcohol is essentially chemical intercooling. I would obviously still recommend an intercooler obviously, but this at least illustrates the point.

[gabedude]

First reply. :P

Nice post. Sums it up pretty good.

[Grynchmeister]

Awesome, thanks for the post!!!

[USNSTI]

Sweet info.

[Davenow]

Like I said, I need to finish going through it. I have some things to add, some things need to be changed etc. This is a couple years old, so it definately needs some updating. But its still pretty complete and 99% correct.

[fourseasonsandles]

Thanks Dave for the update. I just started reading about meth and I really appreciated these well thought out posts.

[evilSTi7]

stuck!

[Davenow]

Yay I got my sticky back

[bluedemon_II]

Theres one ting that I always wondered. Some people are nay with meth on a subaru since the pistons are cast aluminum. I mean the time that the meth spends inside the cylinder before being burned is so small that I highly doubt that it would be sufficient to do any damage.

Can any one chime in with some knowledge of meth related damage? And i don't mean my kit failed and no failsafe kind of damage.

[Davenow]

People have been running meth on Subarus for years now, no one has had any problems with any kind of degrading or anything. The nay sayers are just worrying about nothing based on theories, not on reality. Because real world use has proven that there is no problem. Going back even further, meth injection has been used for decades on turbo buicks (many with forged pistons) with no problems like that.

Actually, on paper at least, the meth is better for the pistons, it damn near steam cleans them, whereas straight pump can build up some crap on them which will eventually turn into hot spots.

[bluedemon_II]

Then this justifies me going into WOT at least once a day lol. Nice faq btw.

[ToeKutter]

Originally Posted by fourseasonsandles

Thanks Dave for the update. I just started reading about meth and I really appreciated these well thought out posts.

^^^^Yea, that! Great write-up, thanks!
So in terms of tuning, do I need to be able to change the ECU maps on the fly (when the meth runs out), or can I at least b able to drive back to the bat-cave and do it there in peace?
Thanks again!

[GhEttOStI]

awsome! just got my smc installed and i love it!!

[Dstretch33]

Great write up this answered a few of my questions without even searching. lol I would assume that upgrading my pistons would add extra insurance with the meth kit and higher boost pressure. Would this be necessary?

[Davenow]

Originally Posted by Dstretch33

Great write up this answered a few of my questions without even searching. lol I would assume that upgrading my pistons would add extra insurance with the meth kit and higher boost pressure. Would this be necessary?

Going to forged pistons is never a bad idea. While meth, if you tune it accordingly, can add a large saftey margin, the OEM pistons have some problems. In my opinion when you decide you want to go beyond something like Stage 2+fmic and meth, you should be looking at doing a set of pistons. yes its not cheap, but its not as bad as many people would think. If you skip fancy coatings and go with stock size pistons, you can often get out of it for under $2000 total. Then you have a motor that should hold well beyond 400whp.

Asking "pro" tuners and 90% of them will say "If its tuned right 400whp is fine, we do it all the time they dont blow up blah blah blah"

Bullisht. I have yet to see a TRUE 400whp car last on OEM pistons. It may hold for 10-15k, but it is GOING to lose a piston.

That said, you CAN go bigger than stage 2+fmic and meth on oem pistons with decent reliability. A TD05-18G 8cm, combined with 650/750cc injectors, meth and a FMIC is an instant spool, crazy low end, FAR better than VF39 top end setup on an STI. The 20G variant (sp?) is better power wise, and still spools very quickly, but you start getting into the area of "be careful"

Also remember, EWGs are a good way of making a smaller, faster spooling turbo, behave like a larger one when it comes to the peak and high RPM power.