Alcohol Injection?

[99gst_racer]

So, is it recommended to run straight denatured alcohol or a 50/50 mix with water? It seems that straight alky provides better results..... Is it simply more expensive or what?

[98spydert]

I didn't have as good of luck with denatured as I do with methanol. I would get knock sometimes, pretty much randomly while running denatured and distilled. I saw random because if I would start knocking, I would let off the throttle and get right back on it and it would be gone. It would randomly knock at 10:1-12:1 no matter what timing advance. I would even get knock as low as 14psi. Since I found a methonal source and switched to 80/20 meth/distilled, I have had much better results.

[99gst_racer]

98spydert - I will be running between 22-24 psi.... What would you recommend setting the boost switch to? Maybe 17 psi? Sorry for all the dumb questions; I am installing my kit tonight and I just want to make sure I do everything correctly. Thanks for the advice.

[j.d.roost]

I have my switch set to 15psi. (on a 22 psi max boost setting).

[98spydert]

99gst_racer - It depends on the size of the injector you're running. If you're running a good size injector (~500cc+) you'll end up bogging if it sprays too early when you don't have much airflow. When I set my boost switch, I would adjust my AFR and timing to where I felt like I wanted it and log a 17-18psi run without the WI turned on. So if an 11.7:1, 20* peek timing run on our shit 91 oct gas started knocking when I came into about 12psi of boost, I knew where to activate the WI. Then I'd set the switch for 12psi or a little less, turn the boost up to 22-24psi, and start tuning with the methanol since I had a lot more fuel above 12psi with the WI on. That method is hard to do without a logging device that can log knock, AFR and boost though. You'd have to rely on watching your boost gauge and looking at your timing curve if you don't have DSMLink or a standalone. If you want a good starting point, 8-10psi would work well and you can bump it up 1psi at a time until you're happy with your logs.

[doug]

Excellent info, dude! You should consider writing a tech article on "How to Tune with a Water/Methanol Injection System".

[99gst_racer]

^^^ I agree. ^^^

Originally Posted by 98spydert

Since I found a methonal source and switched to 80/20 meth/distilled, I have had much better results.

Just curious, but, why dont you run 100% meth? And, how long does a gallon last you?

[Joesmoke]

Just a couple of points:

I run my tank in the back filling an AN-4 line. If you with pump in the back, just remember to prime the system (should do that anyways) or ease into it the first couple of times. Same effect.

Although saying you want a turn on point @ X boost, the goal is to catch knock prior to starting, which is an individual car thing. I had my last system turn on @ 2 psi, to catch any low down problems and always keep that air cool. (straight meth). Problem with non progressive is I was injecting 3gph @ 2 psi and at @ 22 psi. Thats why I went to progressive.

Remember that injecting anything, without adjusting boost or fuel, will get you some degree of bogging. I have heard of people starting with injection and not being happy with it, only learning that they never adjusted their overly rich running car to start with. Being able to play with boost and fuel will net you better results.

Through research, I have learned that although straight water should give better results, cars without IC's liked more of a water mix, and cars with undersized ics preferred more methanol. Has to do with time to atomize in the intake tract VS intake temp.

Heres what mine did on straight meth. Its all good!:
14b stock smic stock 450's
fuel down -10 to -15 on the SAFC
base timing at 10-12 deg.
20-22 psi.

I could not run those settings on the other mixes I tried (windshield washer or straight water)

[coolingmist]

Keep in mind that variable controllers are not necessarily better than on/off water injectionkits. There are 2 basic kinds of water injection.

1) variable controller based on boost
2) boost switch based on boost.

the variable controller can send a linear amount of water through the nozzle based on boost. If you start at 5 PSI and end at 25 you will have much more water at 25 than 5. In order for the variable controller to work the system must lower the voltage to the pump. It raises the voltage to the pump based on boost. The more boost, the more voltage. Sounds great, but the problem is, the lower the voltage to the pump the lower the pressure of the pump. For example if you have a 100 psi pump you will be pushing very low psi through the pump until you are at high boost. The low PSI causes the water particles to be larger. Aquamist is the only company that has a variable controller that has full pressure to the pump. They use a solenoid that pulses on and off.

2) this option uses a boost switch that senses boost and has an instant on. These kits keep full pressure to the pump. A dual stage kit insures that water is always running. The first stage can come on as low as 1 psi and the pressure to the pump is the full 100 or 150 psi. The result is better atomization.

When a progressive controller is at full boost the atomization will be the same as an boost switch activated system, but when you are not at full boost you will not have as good atomization.

[Joesmoke]

Yep, fully agree to all points above. I would use aquamist if-they were able to run straight meth and if I had more money. Neither of those are true so.......

Diy or kits have are an on/off switch based on boost. Been there and done that. I liked it, but it doesnt make any sense to have the same amount of flow @ 2 psi ,as it does at 15 20 25 or more. Add an extra nozzle at a higher boost, and you're now covered from there up but what about the window you just left? I just wasnt happy with that either.

Add a progressive controller that varys pump voltage and you will not have an ideal situation down low. Thought about that too, and really, that trip from 2 psi to even just 8, where there is enough flow of air for atomization, is a heartbeat. Just too short of time to worry about a couple of drops that don't atomize. Not to mention, that the intake air is hot, and the surfaces are hot, that what is not atomized is evaporated pretty quick.

I like the progressive because it offers a linear flow, for the most part, that you can really work with. That being said, I would still suggest even the most basic of systems to anyone, rather then nothing at all. I think its just that good!

[98spydert]

Yes, very good points. And I know the coolingmist vendor doesn't want to pimp out Aquamist products but the Aquamist HSV (High Speed Valve) and FIA2 set up is the best way to fly. Full pressure is maintained at the solenoid (the HSV is this situation) yet the delivery of water/alky is progressive. The HSV acts like a basic fuel injector and opens and closes at a very fast rate. The FIA2 controller tells the HSV allow more or less water/alky by based on rpms. Most people have a boost switch on top of this system. That way when you're driving around town, the FIA2/HSV won't be injecting anything while you're just cruising stop light to stop light. The system will be armed and pressurized but won't inject anything until Xpsi and increase from there based on RPMs.

The reason I don't have this system right now and it's only downfall compaired to everything else available... $$$! I was quoted a whole sale price for the HSV, FIA2, 4 jets, and a few other small parts alone at over $400. I can't imagine what the entire kit costs at list. Like Joesmoke said, even a simple on/off system is better than nothing so if you can't/don't want to pay for the Aquamist set up, get what you can.

[98spydert]

Originally Posted by doug

Excellent info, dude! You should consider writing a tech article on "How to Tune with a Water/Methanol Injection System".

Thanks, I'll see what I can come up with

Originally Posted by 99gst_racer

Just curious, but, why don’t you run 100% meth? And, how long does a gallon last you?

The only reason I haven't moved to 100% is I don't need it. I tried different mixtures and different alcohols and I found one that worked for my needs. Distilled water is less than 50cents a gallon and Methanol is $3.50+ so there's no reason to pay a little more when what I've got works great. I also ran a 50/50 mixture with OK results then replaced my head and a lot of other parts and saw how clean the combustion chambers, intake and exhaust runners, and even the turbine and housing were. I'm convinced the H20 running through the system cleans everything up really well. I'm a believer in the "steam clean" theory

A window washer reservoir lasts me 2 weeks to a month depending on how nice I am to the gas peddle