Yes 10% more fuel on top of the current levels of fuel can cause blow out of spark and shut motor down/cause it to break up. Alot of ppl use the iat table to dump fuel to save motor when iats get to certain point
This tells me your system is injecting more than motor needs. Theres also a few factors with evaporation efficiency and amount of water actually needed to saturate the air stream at play. You may have too much water injected and have a low evaporation efficiency. Excess water suspended in the air could interfere with the combustion process, hard to say.

Again its of my opinion use meth/water if iats are higher than you like or you wantto push the tune to more aggressive levels.

 

The system type makes a big difference. Holley stuff is on a different level. This type of system should see a constant pressure/flow and the amount injected is mainly dependent on the duty cycle. This is a much better method as you have more consistent control. Can't really compare it to a fixed nozzle size PWM or boost switch controlled pump setups. As you mention, It should be tuned exactly like a separate fuel system.

You would need to know the pumps flow capability at system pressure and PW to get an accurate idea of the fluid amount injected. Without all this information it's almost impossible to guess how much fluid is actually making it into the engine. Holley doesn't list the pumps flow/pressure ratings. You might be able to call them and ask?

Your numbers don't make a lot of sense to me. Ignoring the pressure multiplication factor, 100% DC should be wide open or 1000CC. So 50% DC should only supply 500CC of fluid. Seems like VERY little fluid to be causing ignition issues. Have you popped that solenoid off and looked at the spray pattern? Does the solenoid have a nozzle on the end? Almost sounds like they forgot to put the spray nozzle on the end and your dumping in WAY more than 500cc of fluid. Do you go through a ton of fluid per pass? Even if they were running 300 psi that would only be 865cc or so of fluid at 50% DC. Neither should cause ignition issues IMO. Are you sure you have the frequency of the PW correct for that solenoid? The other thing you can do is measure the fluid flow. Turn the pump on and put 12v to the solenoid. This should give you your 100% DC flow per min. I'd run it for 30 seconds. And see how many CC of fluid you have.

I use 50/50 and inject about 23gph of fluid around 280psi. I use a boost switch setup at 16psi or so. I can't even feel it activate. 6 1/4 passes goes through about a half-gallon of fluid.



Personally I don't think your IAT has much to do with alky injection. It does 98% of its good in the combustion chamber. It doesn't do much to cool your air charge before it gets in the cylinder. If you could inject it directly into the cylinder bypassing all your charge air/ cold side piping it would actually do its job better.

Too many alky users get hung up on IAT temps IMO.. There is no accurate way to measure the effects alky inj has on the charge temps as a whole. IAT readings are pointless when using a bulb type thermocouple saturated with fluid.

To put it in perspective...

A Bugatti Veryon consumes over 9,900 gallons of air per minute at top speed. Now in comes your 15gph ( .25 gpm) alky nozzle. How much of a charge cooling effect do you really think .25 gallons of fluid will have on 9,900 gallons of air?

 

Agreed!!! Lower IATs dot mean much. Could be a water/meth soaked sensor. Go outside and hold your finger up, now lick it and hold it up. Is the air any cooler? Nope! But you finger is. Get the point? Also, agreed that all of the work is done in the chamber. It only takes so much to cool a charge. For instance, I'm a career fireman and there was an experiment done by Underwriters Laboratories where they threw a coffee cup full of water into a normal size bedroom fully engulfed an it dropped the temp around 500 degrees, if I remember correctly. Just some food for thought.

 

You ever feel an aluminum intake on a carbed alcohol powered car after 3 consecutive dyno pulls? Lol its ice cold and condensation covers it.

Methanol does alot to cool air, maybe not as much as water but it does have good latent heat/heat of vaporization properties, and it can be seen on logs depending where the iat is and where the spray enters.

 

I hear that argument a lot. But what does it really prove/mean?

You have to think about surface area. The Surface area around a pipe/runner is much less when you compare it to the aircharge as a whole moving through an engine rapidly. Similar to the IAT sensor bulb, the temperature of the charge pipe/intake manifold is not an accurate representation of the actual charge air temp entering the engine.


Also… Meth, water, fuel, etc. requires” X” amount of heat for that fluid to change into a gas/vaporize. By having it vaporize in the intake runner or charge piping you are wasting that energy. It takes energy to make the charge piping/intake cool/cold. That energy would be better spent in the CC instead of wasting it on charge piping/intake manifolds.

I’m not saying aux inj. or an ice cold intake manifold have zero affect on the air temps. Just that they have much less of an affect than most think.

 

If I were you I wouldn't actually tune the car for meth, if you do be conservative because if it ever hiccups you've likely put your stock bottom end in harms way.

With a power goal in mind, I'd be more inclined to have the car safely dyno tuned at a given boost level to achieve the power you want - say 700rwhp and 18psi - on whatever premium pump gas you have in your area. From there I'd bring meth or meth/water mix in, jet(s) placed before the IAT sensor. You'll pick up around 30-40rwhp from the IAT change causing a 2-3* timing increase. You'll only see this timing increase when the meth kit is spraying, so it serves as more of an 'octane safeguard' for your motor when its seeing loaded high boost levels on the street.

 

Also not a good idea on most 50/50 kits IMO.

On most basic setups, I wouldn’t allow the ECU to add timing via Meth induced temp drop. Much more likely to hurt something this way. If you dyno the car without meth safely at 12* of timing and 18lbs on 91 octane, the last thing you want to do is throw more timing at the tune when the meth kicks on. Also to say 2-3* of timing is worth 30-40whp is false. Optimal advance will vary with every setup and so will the power gained per degree. If you’re already tuned for peak torque timing on your fuel, then adding 2-3 or 20* of advance won’t make any more power. Closer you are to peak torque timing the more likely detonation will occur. Start going over this point on low octane fuel and it will almost certainly occur. You should spray your alky inj. well down stream of your IAT sensor. That way it doesn’t have an effect on the tune.

The exception is once you start replacing 25%+ of your WOT fuel with straight methanol. Then advancing the timing is necessary for best performance. Most don’t’ inject anywhere near this much. I replaced 30% of my WOT fuel with straight methanol in my 3.8 buick motor. It was happiest with an additional 4* from the race gas tune. Adding more timing net me no MPH/power gains.

The beauty of the alky injection stuff is you don’t have to be technical. It will work no matter what you do to some extent. Spray enough of it to bog the motor, then back it off a hair and you’ll see a decent performance increase most of the time. It is also pretty forgiving tune wise. If you take a little time and set the kit up properly though it will perform even better.

 

I hope LT1PWRD doesn't mind me joining in on his thread.

I think its pretty obvious I'm injecting too much. I turned it up to 15% and it was breaking up, 12% little stumble but then pulled through, 10% seems to run good. Heck, it may only want 8%. HOWEVER....I may be going about this all wrong and need to jack up the boost or increase timing with the injection. I have NO dyno tuning yet...more on this in a moment.


I took the solenoid/nozzle off and it was spraying everywhere. The tank only drops a little bit (3 qt bottle I think) on each wot pull so its working. The design of this solenoid/nozzle is much different...nothing to come off or change on its end. There's a little piece of wire on the end to help further atomize the mixture.


But let's back up a second and discuss this whole water/meth thing as this for me at least is a more difficult subject to u/s moreso than the whole turbo thing. Lotta opinions out there on the benefits (or lack of) with a water/meth inj system.

In my case, I run about 12-13psi around on low boost with 93 octane. My IAT's are around 130* at the end of a 1/4 pass WITHOUT the injection on. But around town, my heat-soaked FMIC will give IAT's of about 10-20* above ambient and I'll get a 10* rise around town. Usually with the injection on temps drop a little bit below where the IAT's started and keeps them there - no huge drop. So I don't use the injection on low boost...just dont think its doing anything. Now on high boost (16-17-18) I have the w/m inj set to start at 14psi and ramp in fully at 17psi. It just doesn't really like it any earlier than than. Now, I did not do any dyno tuning, so maybe I have to retune for the high boost and w/m inj on a dyno?? As a rule should the timing be increased with the injection? Hell, for all I know w/m inj may not even be needed for by high boost setting but I'm afraid to try int w/o it for fear of deto. Is my IAT's too darn low to get the water/meth to vaporize to begin with???

I'd like to try a 17psi pull on 93 octane but dont want to hurt anything. This is a LQ9 at 12* of timing.

 

Those are impingement type nozzles. They shoot out a solid stream (not atomized at all) And when the stream collides with the pin it atomizes. Haven't seen those used on any alky inj kits before. Suppose to be really good. They typically run lower pressures than the misting nozzles and can create smaller micron droplets.

Generally it's best to get the fluid as close to the combustion chambers as possible. You don't want the mixture to "vaporize" in your charge pipe. You also don't want to spray directly into the side of a pipe where it will puddle.

Like I was saying above with the relatively small 50/50 mix don't worry about adjusting your timing with the alky inj. If you run 12* on 93, leave it at 12*.

130*-150* is nothing. On your 12* tune once you hit 175*+ IAT temps (unskewed by the meth inj) I'd pull out a degree of timing. Also don't worry about your IAT temp drop with the alky on. That is not a value to tune by. Your IAT sensor shouldn't be in the alky stream. If your IAT temps drop when spraying your sensor is too close.

Meth/water might not be needed to keep you out of detonation at lower boost levels, but it will help at all boost levels. The amount needed just varies. Small amounts of water in the combustion process are always beneficial. Read "effects"

http://en.wikipedia.org/wiki/Water_injection_(engine)

Starting at 14lbs and "full in" by 17lbs is fine if it doesn't break up. Generally it's better to have a wider spread. Like 1% at 5lbs and 100% at 25lbs. Looking at the boost levels Denmah runs on a 10.5:1 motor (23lbs T88) on 91 octane with meth inj. I really don't think 18lbs should be an issue for you.

 

I'm just going by what worked on a previous car. Car was fine at 15psi with the mentioned 60/40 meth/water before the IAT sensor. Car gained 30whp with a 2 degree timing advance due to IAT reading, and I can show you a dyno sheet to prove it

I can understand the concern on straight meth, I'm talking about a mix. Water will definitely help prevent detonation. To each their own, I still wouldnt tune a car on the ragged edge with methanol/water mix injected, just way too much trust into a system that could easily have problems in multiple ways and cost a motor.

 

And because your specific setup/tune gained 30 hp with 2 more degrees of timing everyones will? I never questioned your gains. I said what worked for you won't necessarily work for everyone else. And that using a faulty IAT reading can get you into trouble.

 

FWIW I upped timing from 12* to 16* with the injection on and no notable increase in seat of the pants performance. Actually, fuel consumption went down a bit leading me to believe I lost a little power.

At least is was fun trying!!!

 

Last time I was on a dyno with the old turbo it put down 911...I have been running meth for over 12 years as my GN was originally rocking the turbo6 and dipping into the 9's.