Draco

RW99, I need to clarify your reply as well... You are correct that methanol has less energy then gasoline per unit mass when you compare the fuels alone. However, when mixed with air at stoichiometric or richer air fuel ratios (6.4:1 for methanol and 14.7:1 for gasoline), a mixture of methanol has more energy then gasoline per lb of air. I encourage you to look up the energy contents of these fuels, calculate the masses of fuel required to mix with air and you will then see how methanol makes more power. The problem is that you need a huge fuel system to deliver the required flow of methanol to take advantage.

By your post, Nitromethane, with its puny 11.2 MJ/KG energy content would make even less power then gasoline (44 MJ/KG) AND methanol ( 22 MJ/KG). so why would Top Fuel dragsters run this fuel? because at stoich AFR of 1.7:1, the amount of fuel used would result in over twice the specific energy of gasoline.

Imagine the fuel system required to deliver this amount of fuel!

This should help:

http://www.smokemup.com/tech/fuels.php


Finally, there is no upper limit to the power benefits that can be realized as you spray more methanol. Simply put, the more you cut gasoline and replace with methanol, the more power you make - all the way to 100% methanol and 0% gasoline. A 100% methanol setup will make about 20% more power then gasoline.

lcvette

iTrader: (3)

this is an excellent thread... I have a question beign new to aftermarket engine management and using the DFI Gen 7 with wideband, I am looking at a meth kit for my turbo C4 vette and am curious (I admit I have not researched this yet) if you pull fuel and spray meth and are still going by the afr for fuel looking for an 11.2-11.5 afr.. this is still considering that methanol has a 6.x : 1 stoich afr.. are you still safe? I would guess that the oxygen content in the exhaust is stating that the meth is doing well to use up the amount of O2 it has to work with during combustion and that the O2 sensor doesn't care what fuel your using, just how much oxygen is available afterwards noting what portion of fuel was burned and what was not to make its calcs. am I correct here? Again, just trying to do some homework before picking up the meth kit.. also any recommendations? was looking at the snow kit for its simplicity, features and price.

thanks in advance!

Chris

frcefed98

iTrader: (16)

Just going by the WBO2 readings and correcting your tune from there. When you add the meth you will go super rich per WBO2 readings. I've been taking fuel out of my tune to get it back into the 11.5-11.8 range, you will be taking a LOT of fuel out when spraying methanol.

The snow kit looks very nice, I believe MM runs a snow kit very successfully.

Be sure if you are going to run straight methanol to make sure the kit you buy is capable of running pure methanol. From what I understand Juilo@alkycontrol is the only one that sells a pump that is designed to run pure methanol. Coolingmist has one but they won't warrant it if you do run only methanol.

Lines have to be methanol compatible as well, polyethylene hose(my local Home depot carries that stuff), braided teflon hose. I'm running twist lok hose on my kit, the company that makes it states that its alky/meth compatible, but I'm going to upgrade to a poly hose or SS teflon braided hose ASAP. No steel or aluminum fittings and or parts or they will pit and corrode from what I understand.

I'm also getting the meth specific pump from julio or coolingmist depending on how much $$ I have when ordering.
J

Draco

This is a question that comes up quite often and you seem to have a solid grasp on it. You state that the O2 sensor doesn't care what fuel you are using, which is correct. A stoich methanol afr will result in the same O2 sensor voltage as a stoich gasoline afr. The numbers that the O2 sensor controller/gauge spits out (usually between 10 and 18 AFR) are simply calibrated assuming you are running gasoline. With that being said, on a typical gasoline calibrated AFR gauge I'm shooting for the standard 11.X AFR ratio.

lcvette

iTrader: (3)

thats what I imagined would be the answer.. so even though the sensor output states 11.x afr you may be running a meth mixture quite richer then what the result is in the spent exhaust gases reading.

now also stated above was mention of water being a better cooling component then methanol.. I have also read this and although the specific power output of the mixture will go down as water is not combustable, it will in fact add the advantage of cooling the crowns of the pistons while being turned to steam in the chamber. also it helps to keep plugs clean and remove carbon deposits which in turn staves off detonation. so my question would be for a street/strip setup wouldn't it be advantageous to continue to use a mix of meth and water but perhaps change the mixture to 60% meth / 40% water? or until you find a happy medium of the two? I was warned about running straight meth while still using gasoline is why I ask this, I may have been mislead in that statement but for somereason I remember the explanation being sound.

thanks in advance.

Chris

RW99

Thanks for the info, Draco...
I understand the capacity of the stoichiometric mix; I was limiting my viewpoint to the setups commonly used in our street/track cars, and the practical limitations of the current alcohol injection systems.
What do you think the limit is with the normal, spray-it-prior-to-the-throttle body plumbing? Like an Alkycontrol system on an FI application at something like 12 psi on a 346?

Rich

RW99

Oh, and I'm also really interested in the potential benefits of running a bit of water in there... if there's a significant operational benefit (e.g. making the pump/lines/injectors less likely to corrode or clog or fail). Maybe something like 80:20 methanol:water?

wicked_95z

iTrader: (8)

Maybe its just my ignorance but if methanol will increase power over gasoline, why would anyone want to spend close to $1000 on a low imp converter and a set of 60+# injectors over sprayting methanol which can be had for less than $600.

MIGHTYMOUSE

iTrader: (59)

you can't spray as much meth as you want through the intake, eventually you will have wet flow and distribution problems.

also mototrons you dont need an impedance converter

wicked_95z

iTrader: (8)

So methanol doesnt atomize as well as gas. So I would assume methanol is heavier than gas.

I was meaning anything over 60#

MIGHTYMOUSE

iTrader: (59)

not at all, the gasoline doesnt have to travel through the intake and get distributed btwn 8 cylinders on its own

frcefed98

iTrader: (16)

Ran the smaller nozzle today, ran lean....12.0-12.5 a/f's @ 38-4000rpm without doing anything else to the tune, let out because thats too lean for me

Retuned it now with a fatter curve and she GOES No topend bog that I was experiencing with the bigger nozzle.

No KR, no bog and she is running great. Did a lil more clean up on the WOT tune and will be testing it out tomorrow to see how she does. Its too hot outside to do any testing worth a **** right now.
J

MIGHTYMOUSE

iTrader: (59)

fine with you then fine with me BUT if you would have left the bigger nozzle in there and lean'd it out it would be safer AND faster. (assuming there is no alky system hiccup)

wicked_95z

iTrader: (8)

Dohh! I gotcha

Draco

I too wonder where the limits of practicality lie for injecting large amounts of Methanol on street/strip apps like ours. My earlier posts were aimed more theory related to the energy content of the two fuels. I'm not really sure what the output of my alkycontrol pump is, but I think I read somewhere that it can support 25 GPH worth of nozzle with at least 100 PSI. The other question, as MightyMouse has raised, is how much of the methanol can we actually vaporize through the intake. The answer to that probably involves calculus but I doubt many of us are approaching that limit thanks to the massive amounts of airflow our engines require, and the heat in the intake tract.

Injecting large amounts of Methanol may well be better suited to non-intercooled setups like mine where IATs are much higher. This will vaporize the methanol more readilly on its way through the intake. Some of the turbo buick guys are pushing 20+ PSI of non-intercooled boost with their methanol kits.

With my setup, at 8 PSI, I have pulled my VE table fueling from 125'ish % down to 72%. Thats a fair amount of methanol! My IATs are right at ambient, and the IAT sensor is positioned about 4 inches downstream from the nozzle, so that doesnt give the meth much time to vaporize and cool the charge before the sensor reads. Will dyno soon after I re-do the intake plumbing.

frcefed98

iTrader: (16)

Dave, let me get comfortable with this stuff first. To me its like my N2O days. I had to get to know the 75 shot, then after like 2 days I stepped up to the 100 shot and a ton of fun and then stepped up to the 125 shot about two weeks later

To me this is the same, a learning curve so to speak, and I want to be on the good end of that curve and not on the blown engine end

Right now the thing i'm most shaky about it the STS meth kit itself. I'll be stepping up to a snow or alky control kit when the funds are there.

I've got to get it to the track now to see where she stands and to iron out the upper rpm's of my VE table.

I'm really wanting to try out a dual small nozzle set up to increase the meth.
Thanks,
J

RICE ETR

iTrader: (3)

I just compared how much meth i was spraying to how much fuel the wet shot guys were spraying, safely, and tried to stay below that. Being below this and using alcohol which should vaporize much better than gasoline makes me think i am ok at the levels i am at. But as far as i am concerned, the more meth, the more power......I just started believing this after some minor convincing

KySilverado

iTrader: (7)

I just installed an Alky Control kit on my truck. Got it in yesterday. Without touching the tune and first few test runs yesterday I am hooked. SOTP difference was amazing. Running "Heet", haven't found a source for meth yet, my AFR also went very rich. 9.5:1 at progressive controller pegged, to 10.0:1 at about a 12 o'clock setting. Absolutely no bog. Can't wait to get to the track and do some tuning. Pulling fuel and adjusting spark timing based upon IAT's. I plan on running it all the time. Looking into some fail safe to throw the truck into limp mode should the meth fail.

Great thread!

RW99

Cool, can't wait to get my Alkycontrol on the car.

As for that "failsafe" idea, I'm thinking that the critical parameter that tells you whether you're actually delivering methanol is the IAT. Does anyone have a method to rig up some sort of indicator light (GET OFF THE THROTTLE NOW!) that could tell you if your IAT's went above a certain setpoint while at WOT?

Methanol reservoir level and supply line pressure are nice to know, but if you've got a clogged nozzle and aren't actually delivering the methanol into the intake tract then you'd miss the failure.

wicked_95z

iTrader: (8)

I know on my alky control kit, Julio has added a dual color LED. It turns red when the system has turned on and then it turns green once the pump builds pressure. No pressure, no green light as I understand it