The Science of corn and other sprayables (Discussion)

[Enki]

OK so since it seems full E85 is about to make a huge resurgence on this platform, now would be a good time to discuss some of the science behind how it works and why. Because this discussion will be closely tied in with other fuels and methods of fueling, it would be worthwhile to include them in the discussion.

For now, I'd like to limit the discussion to pump gas, Ethanol (blended and non), Methanol (blended with water and non), and water itself (which I know isn't a fuel, but fits in the scope of the discussion).



Starting off, some anecdotal history regarding my own recent experiences with full E85:

If you follow my thread, you'll know I dynoed the car recently and put down 360/340 with wheel spin on E29 with TMIC and WMI (a D08/8 GPH nozzle spraying M60 or 60% meth, 40% water). Immediately thereafter, I went and filled up with E85.

When I first cut over to full E85, I left everything as it was, map and all (except I dialed it back to spring pressure boost wise).

This configuration didn't run very good at WOT, as meth was kicking on and boost temps were in the 50s to 60s. At first (on the way home) I thought I was out of fuel on spring pressure, but this turned out to not be the case. I didn't feel any smoothness change just cruising around either, despite experiencing this effect on stock turbo; though this should become more relevant a bit later. On this map I made about 250 WHP @ 12 PSI with 18 timing @ 6k per VDyno. Slow as balls. I disconnected the WMI, and it ran quite a bit better, with BATs climbing past ambient (80s); it even made 20 more at the wheels with the only changes to the map being lean cruise and .5 reduction in target AFR to 12:1, which in itself shouldn't make hardly any power (unless pre-combustion cylinder temps were too low at the richer AFR).

So since it was running better, I turned the boost up to find fuel limits (not hard), and got it to about 300 WHP, TMIC only (no meth). Then, I removed the TMIC all together and ran no intercooling whatsoever. Power? 295-300 before BATs climbed past 200. After that, obviously, power fell off due to air density and the low response rate that the tune had to try and cope with the lack of airflow when things got hot (load tune, not boost tune).

Then, I plugged the meth back in, and gained another 20 WHP with no changes to load targets or timing. I should note here, however, that it seems that VersaTuner will reduce load when IDCs go past your map set limit, so up top I'm not even hitting targets (yet). Boost levels didn't seem to change much between the 300 WHP and 320 WHP tests though.

That's it for the story, but you might want to go back and re-read it after chewing on this next section, as the progression should make a bit more sense.



Now for some terminology so we are all on the same page; all freshly copy/pasted from Wikipedia:


Flash Point
The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source. At the flash point, the vapor may cease to burn when the ignition source is removed.

The flash point is not to be confused with the autoignition temperature (which does not require an ignition source) or with the fire point (the temperature at which the vapor continues to burn after being ignited).

Neither the flash point nor the fire point is dependent on the temperature of the ignition source, which is much higher.


Autoignition Temperature
The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical will ignite decreases as the pressure or oxygen concentration increases. It is usually applied to a combustible fuel mixture.

NOTE: In the cylinder, autoignition is an aspect of and/or can be considered knock.


Latent Heat
Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. An example is a state of matter change, meaning a phase transition, such as ice melting or water boiling.

NOTE: This is important for the water discussion.


Got all that? Fuckin liar. Anywho, moving on to the properties of the fuel at hand (also from Wikipedia):


Gasoline:
Flash Point: -43C -45F
Autoignition: 280C 536F


Ethanol (E70):
Flash Point: 16C 62F
Autoignition: 363C 685F


Methanol:
Flash Point: 12C 54F
Autoignition: 385C 725F


Water:
Boiling Point: 100C 212F



Notice anything right off the bat? You might not unless you've ever run full E85 in the winter. Those cold start woes could very well be attributed to shitty vaporization due in part to the cold ambient temps but also the fuels ability to soak up heat. Same goes for why it runs shitty until the engine coolant temps reach triple digits. Should be pretty obvious why gasoline doesn't have issues with cold starts while corn does now too.

Neither of those is a big deal, but there's another issue I encountered (that Phate also encountered, though probably to a slightly lesser degree). Remember when I first cut over to full E85 and it ran like shit? My BATs were in the high 50s low 60s. Now go back up and take a look at the flash point of ethanol. I bet the light bulb just came on.

So, it would seem that 60 degree boost temperature, plus the heat of compression and any radiative and conductive heat transferred to the fuel wasn't enough to properly vaporize it in the cylinder, and thus, it didn't run very good.

I want to take this analysis a bit further though. Let's say for example, I went back in time and the car was on the dyno at the E29 map. Looking at the boiling point of water, it's fairly plain to see that the water wouldn't be boiling until AFTER the ignition event in the cylinder; from what I read when looking up information on ethanol, water injection can result in a reduction of power if not properly tuned for it.

You might be wondering why this is even remotely relevant; well, when I made 20 more at the wheels just because of WMI with no intercooler, my boost temperatures would easily have been above the boiling point of water, whereas on E29 they would not have been.

Thus, I'm currently operating under the assumption that it actually cost me a bit of power when I was still on E29. Again, why would this matter? Well, it seems to me that the best times to use water injection would be either pre-turbo (it would vaporize in the compressor where all the heat is made), or post turbo before the intercooler (if you have one) to further reduce temps for, say, a stock turbo car; any other location or use could actually hurt your power production. This is why I will be switching over to M100 shortly and waving goodbye to water.


On to some more information and theory crafting:
Currently, I'm running a boost switch to control my meth engagement. It's set to right around 10 PSI, which is my spring pressure; I'm probably going to turn it up to 12 or even 15 PSI later on, depending on my future testing as it can be problematic due to the fact that it comes on all at once currently when part throttle (again, too much cooling in the cylinder, not enough heat out of the turbo).
I'm also going to be swapping out to a pair of 5 GPH nozzles spraying 100% meth, both for supplemental fueling up top as well as the slight increase in cooling capacity I'm hoping to get out of it so temperatures stabilize in my chosen BAT target of 120-130 degrees. I don't want it too cold in the cylinder to prevent vaporization/misfire issues, but I also don't want it too hot to prevent reduction in combustion efficiency and airflow at a given boost level (which could become a factor later on since I'm only running a 10 PSI spring).

Now another thing to note is that my current cruising BATs are in the 100-130 range as it is, though it's not unusual for them to climb to upwards of 180 in city driving (and they do come back down when cruising). Why do cruising BATs matter? For the same reason that WOT BATs matter: Vaporization. I'm currently running about 21-22 MPG, which is higher than I've ever had previously on full E85, and I think my higher cruise BATs have a role to play in that (better vaporization = less unburned and thus wasted fuel). Also, the car runs a touch smoother than it did with the intercooler on it.



So to sum up, these are the conclusions I'm currently operating under:

1. Full E85 is fuckin awesome
2. You want BATs in the 100-130 range to run properly on a big turbo, less on a stock turbo (due to reversion, cylinder filling inefficiency, etc)
3. Don't use any water in your WMI spray unless its being injected into high temperature air (pre-intercooler) or pre-turbo; use M100 if you can
4. Hot cruise BATs can (might) improve economy on full E85
5. Intercooler delete on full E85 is pretty awesome, but probably won't work well on stock turbo and/or stock exhaust manifold


Let's discuss.

[SarcasticOne]

You've said before going full e85 increases air flow.... Can you expand on that?

[phate]

Originally Posted by SarcasticOne You've said before going full e85 increases air flow.... Can you expand on that?

I know it's been mentioned here and there, but dyno results don't really show this. I've taken K04 cars with low mixes to full e85 to MBT on the same dyno and they all make within ~10hp of each other. Some cars with lower mixes made more power than cars with higher mixes. I've attributed those differences to hard parts setup, not fuel.

The biggest limitation with only gas is knock. E85 removes that limitation. I suspect a sufficient octane gas would make similar power to full e85, simply because you can run sufficient timing and boost.

[Enki]

Originally Posted by phate I know it's been mentioned here and there, but dyno results don't really show this. I've taken K04 cars with low mixes to full e85 to MBT on the same dyno and they all make within ~10hp of each other. Some cars with lower mixes made more power than cars with higher mixes. I've attributed those differences to hard parts setup, not fuel. The biggest limitation with only gas is knock. E85 removes that limitation. I suspect a sufficient octane gas would make similar power to full e85, simply because you can run sufficient timing and boost.

Have you seen boost drop @ 100% WGDC but airflow stay the same on those cars when they swapped to full corn? I had a similar experience on stock turbo, and I'd wager that you wouldn't receive too much in the way of airflow benefit at high rpm on stock turbo, but I'm pretty sure I'm experiencing it right now.

17 PSI and 4.05+ MAF volts on full corn vs 21 PSI and 4.2 volts on E29 with intercooling and WMI.

[SarcasticOne]

Originally Posted by phate I know it's been mentioned here and there, but dyno results don't really show this. I've taken K04 cars with low mixes to full e85 to MBT on the same dyno and they all make within ~10hp of each other. Some cars with lower mixes made more power than cars with higher mixes. I've attributed those differences to hard parts setup, not fuel. The biggest limitation with only gas is knock. E85 removes that limitation. I suspect a sufficient octane gas would make similar power to full e85, simply because you can run sufficient timing and boost.

Am wondering then why people say there is a noticeable difference between e42 and e85...
Just wondering why same airflow + timing causes it to feel faster?

[CHUNKYBOWSER]

Yesterday I finally performed my first log with my new meth kit on my car, so this is very relevant to me. I only managed one log last night since I'm just driving again since I broke my ankle, but for some reason my car was down about 40hp from the last time I logged. Temperature was 15 degrees hotter outside, but there's no way that accounts for 40hp. The only thing that changed was the installation of pre-TB 50/50 meth (roughly, I just eyeballed it for these first tests).

Based on your testing, I'm starting to think that maybe the water stole some power. Then again, I may have a different problem, who knows.

[Mauro_Penguin]

I've read about e85 mixes for a while, and I'm not daring enough to switch into it.

Your new results with the red line fuel cleaner are great though.

I've always thought that guys running high e85 and meth suffered from too cold of operating combustion temperatures. Which explains why some BT threads I've read on different platforms don't have ridiculous boost. If e85 cools your EGT so much that it slows down exhaust velocity and volume, then it would explain slower turbo response upon initial spool. Am I on track with that or is my assumption exagerated?

Your results with fuel vaporization and proper mixture just add to the explanation. This just confirms that things can be too cold. I've discussed things like this year's ago with some old hot rodders. They looked for ways to keep their fuel warm and pressurized on carbs, but that's a whole other story and discussion.

[phate]

E85 does not reduce egt. Similar power, similar heat.

[littleloogy]

When I was on E and trying to get as much power out of my K04, I found that blocking off 40% of my tmic raising my BAT's would yield more power. I would also found that leaning my mixture to 12.4 helped too, it also allowed my to run more boost towards redline without running out of IDC. Timing did not do much for me on full E.

I'm not sure about exhaust temps, but cylinder temps are cooler. There is so much unburnt fuel left in the cylinder after each cycle. I have heard that indexing spark plugs will help with burn. Does anyone do this?


Sent from my iPhone 6

[Mauro_Penguin]

Originally Posted by littleloogy .... I have heard that indexing spark plugs will help with burn. Does anyone do this? Sent from my iPhone 6

Beans Above the Frank Build not sure if you want to give it another go but Silvapain had issues with indexed plugs.

[Enki]

I might try leaning it out further, but not quite yet.

[silvapain]

My issue with indexing plugs was getting the damn washers out of the head afterwards.

[Enki]

Did you get any benefit though?

[silvapain]

Originally Posted by Enki Did you get any benefit though?

Nothing measurable.

[littleloogy]

On our small engines we saw gains. But this is a whole different ball park with disi


Sent from my iPhone 6

[Enki]

Read a bit earlier that water has about double the heat capacity compared to methanol. It's possible I'll be going to some kind of mix when I get my boost switch thing figured out.

[littleloogy]

LOx will make some power. Try spraying that.


Sent from my iPhone 6

[Enki]

Sticking your tongue in my butthole will to. Let me know how much hp you get at the crank.

[sheston]

When you use enough E to surpass the knock threshold, what is the mechanism for increased hp after that? You can't advance timing more, boost is probably already maxed, etc. I thought E had less "energy" than gas, ....

I've always wondered what difference it makes between BATs and the actual pre ignition cylinder temperature. Does that make a difference?

[Enki]

More fuel and boost probably.

[Enki]

So, the experimentation begins; I currently have surplus fuel even at 20 psi but am out of cooling.

I'm going to increase my spray amount by another 2 GPH and see how that does with cooling. If needed, I'll start to decrease my meth percentage to try to increase cooling without losing too much fueling by adjusting nozzle size.

[Enki]

Cross-posting from my EFR thread:

Originally Posted by Enki Just ordered two more nozzles and a spare boost switch, which I'll probably reconfigure to use the middle port on the bunged coupler for better response from the WMI setup, and make it easier to adjust the switch pressure. When everything arrives, I'll be ditching the Full Race vacuum/boost distro block to help clean up the bay a bit, and I'll probably mount the switch to the ECU/battery mount. The nozzles I ordered were a 6 and an 8, both of which I already have one each of; combined with the dual 5s that are already installed, this is now my GPH capability assuming a max of two ports being used, minimum 1 port used: 5 GPH 6 GPH 8 GPH 10 GPH 11 GPH 12 GPH 13 GPH 14 GPH 16 GPH Currently the plan is to switch to 12 GPH of flow, drain the tank and mix in some water (20%) to see how that does at 20 PSI. All in all, I should have significantly more cooling capacity: 20% more flow from 2 GPH increase in nozzle 20% more cooling from 20% water mix

[Enki]

So I tested swapping from M100 down to M80 today, and this is what I found:

1. Peak torque was made later on M80, but temp (ambient and boost) could be a factor
2. Peak HP was slightly higher on M80, but temp (ambient and boost) could be a factor
3. Cooling effectiveness was either the same or slightly worse on M80
4. IDC increased by 3% on M80

Running a mix is probably best for wallet economy as you can run a bit leaner, and water is far cheaper than meth.

That said, I'd personally rather have more fueling headroom and what might be a slight bump in cooling so I'm going to mix the M80 back in with the M100 I have (should result in about M92-M97 depending on what I actually have in there) and I'll burn that out probably during testing/tuning.

[littleloogy]

Have you thought about using the back plate from the pump I sent you? Maybe run a line to that? That way you don't have to worry about buying meth all the time. I wonder what the cooling affects are of e85


Sent from my iPhone 6

[Enki]

Originally Posted by littleloogy Have you thought about using the back plate from the pump I sent you? Maybe run a line to that? That way you don't have to worry about buying meth all the time. I wonder what the cooling affects are of e85 Sent from my iPhone 6

That's an interesting concept, but if I'm going to go that route, I might as well do 5th port, and I'd rather not go that far.

I'll stick with the meth for now, but testing cooling of corn vs meth should be doable. I have a little spray bottle or two somewhere I can use for temp measurements of a hot plate.

[aaronc7]

Other sprayables.... I will donate some of my own fluids for testing purposes. PM me your address.

[littleloogy]

If corn does cool well, maybe you can still hook up a line from the pump to the meth tank with a valve. Then the tank can be topped off whenever you want. Just some ideas... Either way you are doing a great job in exploring this new concept


Sent from my iPhone 6

[Enki]

I probably won't do that, as I don't really want E85 in my washer res, but it will open up options for others for sure. Maybe refit a float bowl configuration from a carb to the fuel line and a small supplemental tank or something like that, or maybe just set up a surge tank and drain from it instead; that should work too.

[Enki]

Enki's EFR Ordeal...

[littleloogy]

Let's see the power!


Sent from my iPhone 6

[someguyondrugs]

any idea on the effect e85 has on emissions testing?

[Enki]

Google says down overall, with an increase of acetaldehyde.

[MD1032]

Good discussion. I don't really have an explanation for the phenomena you've observed, just some observations:

1) Those flash point and autoignition temperatures you posted are for atmospheric pressure. I don't know if they decrease linearly as pressure increases, but they probably don't, therefore, the fuels may behave differently in cylinder.

2) You didn't post the enthalpy of vaporization of the fuels in your post, so here they are:

Gasoline: couldn't find a single value for it, see below
Methanol: 35.278 kJ/mol
Ethanol: 38.56 kJ/mol
Water: 40.65 kJ/mol

...and on that topic, I have attached an article you will surely find interesting and relevant. Right in the intro they mention the fact that gas-ethanol mixtures have a tendency to phase-separate on contact with water, and obviously that's going to give your in-cylinder mixture totally different properties regardless of what gas-ethanol mixture you're injecting (which means you can throw all the above numbers and all the other numbers you find on the internet into the garbage as well). Unfortunately I do not have time to read the whole thing currently, so I will read it tomorrow morning.

3) The way flash point is determined, by putting the liquid in a cup and passing a flame over it while increasing the temperature, makes it irrelevant here IMO, because volatility, and the concentration required for it to autoignite relative to whatever oxidizer is used (I don't know lol, honestly, never used one before) plays such a huge role in the outcome of the test.

Now having said all that, I'm not saying you're wrong. And I think you're on to something here. Of course temperature affects volatilization of the fuel, and of course different temperatures are optimal for different fuels. But don't take these, values, even the ones I quoted above, and try to dissect them, because once the charge goes into the cylinder and is heated and pressurized, especially once you're throwing methanol and water into the mix, it's a totally different ball game than the standard pressure and temperature used to generate many of the above values.

My initial instinct is that I would be interested to see what kind of results you'd get with a leaner fuel mixture. You have more than enough knock resistance and cooling to try it.

I'll re-read your post tomorrow with fresh eyes and think about this some more. Right now I'm wondering if I should post this because I can barely see the screen nor think straight. haha

[chaser27]

Just a little note since it's been a long time since I've studied physics at a truly scientific level.
I wouldn't be trying to use water as my air cooling mechanism instead of meth. Water is better for keeping your in cylinder temps in check. You can run leaner and use the water to absorb heat instead of excess fuel. Giving you more headroom if you're running out of fuel and better fuel economy. Meth has a lower specific heat that makes it better at cooling the charge air quickly.

[Enki]

As the IATs go up, so do the BATs. 90+ IAT today and even 16 GPH can't keep up.

Next up: Pre turbo.

[MSP6]

Go'on you gearhead you, make us smarter.

[littleloogy]

Originally Posted by MSP6 Go'on you gearhead you, make us smarter.

I had to log into my phone browser to see what the fuss was about. Awesome work @Enki; this you deserve.


Sent from my iPhone 6

[sheston]

I don't think Pre turbo meth made my BATs any lower, seemed to flow a little more.....

Be careful, I believe some sort of back fire with pre-turbo meth was responsible for destroying my MAF sensor

[Enki]

I'm not really a big fan of 160-180 IAT/BATs when driving in the city, so the TMIC might have to go back on after all. Fucking desert summers.

[mxlplx71]

Originally Posted by Enki I'm not really a big fan of 160-180 IAT/BATs when driving in the city, so the TMIC might have to go back on after all. Fucking desert summers.

do you have tig's?
since i have 4x3gph in the intake runners and 6th port im considering trying to bypass the fmic to reduce lag on the gt3076r clean up the engine bay.

its hasnt gotten hot here in iowa yet but my intake is always cool to the touch after any driving. bat's havent gotten over 100deg running 30lbs