Whats the right ratio?

[xtrempickup]

I was reading in Turbo Magazine today this months issue they had a write up about Water and water/Methanol mix injection. it says running plain water is good for cooling, but running a 30-40% mix methanol and water would be good for addtional cooling and cheap hp, better economy, the ability to run cheaper gas, etc. It says anything over 30%-40% water to methanol is deterimental and more likely to cause detination. I'm running 75% alki to 25% water mix in my car. I talked to other ppl, some running full 100% methanol. is there any truth to the ratio suggestion? is less alcohol to more water better than a higher amount of alcohol to less water? im trying to figure out what would be more beneficial in my R/T. right now its a M7 Nozzle with 75/25 alki to water mix pumping in and i dont notice any issues, but was wondering water other ppl are doing and see with 50/50 and if anybody is running more water in their mix.

[Reaper1]

I don't see how more alky is going to increase detonation. It has an octane of about 100-103. It helps cool the charge and slows the flame propogation.

That being said alky does need a much lower numerical A/F ratio to be stoich...6:1 I think is what I read someplace.

At any rate, most peope run a mix. I personally run 40/60 meth/water.

What all is done to your engine?

[xtrempickup]

my motor is stock TIII bottom end, 54 trim stage T3/T4 turbo, ported intake and exhaust manifolds, 58mm tb, fmic, stage 3 cal, +40s, 3bar, running 21psi

[Reaper1]

I would up the meth ratio, but other than that, if the engine seems happy, I'd say you're good!

[xtrempickup]

this is a crappy way to figure out stuff. il already at 75% meth/25% water i might as well run full meth straight if i go any stronger. i was hoping somebody on here could interject some knowledge of tuning or running this stuff and might have dyno info or something to support

[Reaper1]

I thought you were only running 25% meth. I appologize. For more information beyond this you might want to check out the forums on the Devils Own site. There's some pretty decent information there. Beyond that, more detailed information can be found in old NACA doucments(yes, NACA, before the current NASA) about water and methanol injection. There is a point of diminishing returns, but I can't remember what it is off the top of my head. I'd say you are probably at the upper end of the spectrum.

Each set-up is going to react differntly. Messing with it is going to be the only way to know for sure without some very powerful computer modeling or some intense math!! I hope you're up on your chemistry, thermodynamics, fluids, and physics!!!

[puppet]

Quote:

Originally Posted by xtrempickup this is a crappy way to figure out stuff. il already at 75% meth/25% water i might as well run full meth straight if i go any stronger. i was hoping somebody on here could interject some knowledge of tuning or running this stuff and might have dyno info or something to support

Just something to consider ... I don't use injection personally either but ... as you know, water isn't a fuel. Meth/eth are fuels. As that article you read probably states, WI yields better cooling. Meth provides that plus additional fuel. It's not uncommon for people using more (or straight) meth to have to remove fuel to maintain power levels. The more you add, the richer the mixture becomes.

Stands to reason that if you intend on using 100% meth/eth you'll need to adjust your fueling maps accordingly to actually reap the benefits. Perhaps reducing fuel by 20-30% when spraying. A lot of people use straight meth injection and aside from the potential corrosive reactions, they don't see any "bad" things happening ... let alone an increase in detonation. That should definitely not be an issue.

So that's the rub. WI provides a simple cooling effect while adding meth in greater amounts begins to compound the fueling ratio problems when trying to achieve the optimal tune. You'll need to do more work here with regard to fueling and timing to get it just right.

[glht_omni]

Quote:

Originally Posted by Reaper1 I don't see how more alky is going to increase detonation. It has an octane of about 100-103.

on the devils own site, it says something about 116 octane? whats that about?

[speeduphoria]

Ethanol is like 105 and methanlol is much higher. I saw something awhile back saying that some mix was equal to 116 octane(think devils own posted it on srtforums), which given the meth to fuel ratio would not make sense when using a diluted mix, but the cooling may.

Basically if you cant change your fueling or timing for the meth injection your best off using a small nozzle and low meth to water mix. On mine I run straight meth but this is because my walboro cant flow as much fuel I need to hit my goal. I also have the timing advanced a couple degrees where it sprays and can adjust the fuel to keep the A/F ideal.

[glht_omni]

Dodge Srt-4 Alcohol water Injection DevilsOwn Injection
thats where it says "with methanols 116 octane"
i havent bought 110 octane since 03 but my dad does and its like $6.50 a gallon, so if you could pull 110 out of it with 93 pump gas, it would be worth it ($3.50 a gallon gas + $1.00 a gallon washer fluid) you got $4.50 a gallon for a race gas equivalent that you only burn when you need to, thats awesome.

[speeduphoria]

I would say its prob comparable to 110 gas, I get 100% meth for ~$3.25 a gallon, 5gallons at a time down here, was hard to track down though, ended up getting it from place that sells propane as they put some in the tanks to absorb the water.

[glht_omni]

i havent even checked on 100% meth prices yet, but i am sure between detroit and all the farmers and tractor pull events out here i could probably score it as cheap as anywhere.
i heard one guy say $2.40 a gal, if you were to dilute it 50% with water $1.20 a gal. either way it still better than paying for turbo blue and having to have a full tank of it to have it on demand.

[turbokid]

what turbo mag do yall subscribe to. I would love to start reading some of them in the mail

[speeduphoria]

I use the internet personally, just dont believe everything you read

[Gutfeeling]

Running the correct amount of meth/water depends on how much timing advance and boost you're pushing. There really is no ratio as per every tune will require a different calibration. Although the tested and true way to find out is trial & error. In my experience, running more timing will require more meth in the mix and for lower egt's you'll want the water. That's just from past experience and could have error in it.