Making the switch to e85, do I still want to run meth?
 

I've been gathering up all the parts that I need for my changeover and I'm wondering if I should still keep my meth injection now that I decided to go e85?

Not generally needed.

If your E85 is like ours in PA, you may want to verify the ethanol content. If we get over E70, it's a surprise. If you're running "race" or verified E85, I don't think you'd need it.

How can you verify the content?

.

E85 test kit. It's a little tube that the ethanol and gas separate in to show ethanol content. Very easy and can fit in your pocket.

X2 Unfortunately it seems the east coast stuff varies quite a bit. And it's not available on every corner either. I'm jealous of the you Midwest guys!

The knock threshold difference between 70% and 85% ethanol is VERY little. Most builds would notice little difference between the two. Guys making 1000+ at the wheels on E50 @ 10:1 with basic LS setups. IMO there's no reason to not run water/meth injection with e85 if it's already installed. I'd suggest a smallish nozzle (5-7gph) with 50/50 to help cool the CC. It's cheap added insurance.

If I were to run it should I bring it in early like I have or set it up to come in at a higher boost level. If I could eliminate the system all together I wouldn't mind it

I'll be running both. Flex fuel setup so when I'm on 93 the meth will still come in handy.

If I'm going to run just e85 should I bother with meth though? If I don't need it I'd rather eliminate it

Just made 973/855 on the dyno the other week with my car on e85. 10:1 compression, 18 degrees of timing...not a hint of knock. I wouldn't bother with it.

I'm looking to be in the 11-1200 range. I'm in a heads up class and I'm really heavy so I need to push this combo as far as it will go

Tell that to the pa e85 guys

Is car intercooled at all? It wouldnt hurt to leave it to keep iats cooler if not intercooled. If it is intercooled i wouldnt bother with it

A very well known university did the study and published it. It's been a while since I've read it, I'll try to find it again. They used variable compression ratio pistons and tested knock threshold at different ethanol percentages. Detonation threshold was not linear and results lessened over 50% or so.

We rarely get over 70% here in KS, I run it alot.

I'm actually upgrading to a big bell intercooler

Goes in depth in the link below.

http://www.nav200.delphi.com/pdf/tec...10-01-0619.pdf

Wtf! I can't read that much! Lol so basically anything over e50 I won't see much of a difference is what I take from this right?

I highlighted the good parts and supplied a picture! There's only so much I can do... ;)

I think Zbrown has pretty much proven this point making 1200 hp plus on a 10:1 LS on E50.

What's your opinion on me running meth forcefed86? Should I skip it?

I think too many people believe meth/water injection's only benefit is cooling charge temps. When the typical kits actually do very little of that. Water/meth provides benefits in combustion that an intercooler can't provide, so I run both.

I've always run straight meth

Same deal, meth adds octane and slows combustion. I'd run a 50/50 mix so you have some water in there pulling heat out of the CC. You probably have all the octane you need.

I would still run it. The benefits are just too great.

Water pulls an immense amount of heat from the cc. More than the switch from gas to E85 and an intercooler combined are capable of.

Methanol provides a decent octane boost, although not as big after the E85 switch, but it also cools intake air without reducing efficiency or causing pressure loss. Even if I ran E85, I would run water/meth because the water will keep the cast pistons cool and the ring-lands intact, and the methanol will reduce the amount of CFM being forced through my un-ported heads giving a free power increase, octane aside.

A small pre-intercooler nozzle spraying meth also increases intercooler efficiency. If you already have the kit, there is no reason not to. E85 + Water/Meth has the knock resistance of running pure methanol.

I wouldn’t say it offers anywhere near the same knock suppression/octane as straight methanol. The typical meth inj kits don’t inject diddly volume wise.

At 200 psi the most the alky kit pumps are capable of is .5gpm. (30gph) and they pump less at the commonly used higher pressures. (Mine is sold as a “300 psi” pump)

Using my engine setup with rough math as an example:

900 crank = 1350 CFM = 10,100 gallons of air per min.

Even if I injected the pumps max 30gph, that’s roughly 20200:1 ratio of air vs fluid in the charge pipes. This changes the charge temps very little as a whole IMO. Also it has nowhere near the impact a methanol fueled engine has in the CC burned at the 4:1-5:1 air fuel ratios.


It’s true water absorbs much more heat than methanol, but it isn’t flammable. I always had ignition problems injecting any decent amount of water. Even at 50/50 ratios the truck LS square coils couldn’t fire off 16gph worth of 50/50 without dropping a lot of power (lost 3mph at track). Turning off the meth inj gained my 3mph back. Since I’ve upgraded the coils to the D585 I can turn the meth/water back on without losing any mph…

On the other hand, you can inject about any amount of straight methanol you want with zero ignition issues, though distribution gets to be an issue at higher volumes.

We were just talking about his in detail on YB. I don’t claim anything said above is a fact… just my opinion. Pretty interesting stuff.

http://www.yellowbullet.com/forum/sh....php?t=1603034

Water begins pulling heat from the cc as soon as it enters it, not doing combustion only. As soon as compression starts, the water quickly evaporates and pulls a huge amount of heat out. It has basically all evaporated before ignition happens, greatly reducing the chances of detonation. Most people think that most of the detonation resistance comes from the methanol, which isn't true.

Don't forget, your 20200:1 ratio is volume, not weight. Air/fuel ratio is by weight so go by the 14.7:1 ratio to put that into perspective.
Since air is .08637 lbs per cubic feet and water is roughly 62.42 lbs per cubic feet (both at 0 degrees Celcius), you are looking at a 1744.674:62.42 ratio by weight, or a 27.95:1 air to water ratio.

Further math compounds the problem, because the weight of air changes more by temperature than liquids do.

100 degree IATs gives air a weight of 0.07094 lbs per cubic feet. Lets say 80 degree water is being injected, water is 62.00 lbs per cubic feet at 80 degrees. So your 20200:1 ratio becomes 1433:62 or a 23:1 ratio.

I can do the math to show you how much air temps change when you have 400 degree compressed air and 80 degree water. Water isn't really the charge cooler, its the methanol. Even though it only absorbs half the energy per mass to change temps as water, its evap temp is so low that it will continue pulling temps down far beyond what water is able to do in the charge pipes. Water has trouble pulling air temps below ambient, methanol can drive temperatures much lower, and absorbs almost as much energy as water when changing from a liquid to a vapor.

Mass and weight are very different in physical sciences. I believe air/fuel ratio calculated by mass. Which is easier calculated via volume and converted to mass based on temperature and density. Meaning if we are talking straight ”gas”… For every cubic foot of gasoline that enters the CC approximately 14.7 cubic feet of air is needed to obtain a “stoich” mixture. My point being the amount of meth or water most of these kits inject does little to charge temps as a whole. It’s like pissing into the wind and expecting a large temperature shift. Regardless of how heavy that piss is… there’s too much air to make a large difference in overall temperature.

Regardless of weight, you still need a molecule of water to come in contact with a molecule of air. Then you need time for the water to pull heat from the air. With air rushing by at say 300FPS, there is very little time from the injection point to the CC. For water to be effective at removing heat from the charge temps you’d also need well over 212* to flash the water into vapor. If you take pressure into account (just like a radiator) Water in a 240KPA (20lbs of “boost”) charge pipe won’t boil/flash until 260*+. So it’s safe to say water sprayed post IC won’t “flash” until it hits the CC… Again, I believe it will have little effect on the charge temps as a whole.

Much like race gas, methanol adds octane. The more methanol in the CC the slower your flame front will be. Unlike water, methanol is flammable. So there is no real limit to the amount you can spray. Meaning you can up the volume considerably without ignition issues. This is why (IMO) methanol is considered more effective. You simply can’t spray the volumes of water needed without ignition issues to match straight methanol. Assuming we had ignition systems up to snuff, it’s been proven you can run stoich air fuel ratios without detonation under heavy load/boost with “low octane” fuels.

Wow, you guys don't mess around! Should I continue running straight meth? My big question is should I tune without the meth and get the afr at a safe range then add the meth in and run it rich or do I tune with the meth? I just worry about a failure in the system and going lean

Mass and weight are different but if you assume the same gravitational pull then they are the same for figuring out the correct ratio of gasoline to air. Do you think that one cubic foot of gasoline has the same mass as 14.7 cubic feet of air?

I don't think that is what he was getting at. Obviously they don't, but the ratio is calculated off of mass, at least it should be. Corrected weight is a close enough value but a tad harder to work with as every gas, or ethanol blend will have a slightly different mass to volume ratio & specific gravity.

At the O2 level it is worth noting that the extrapolated A/F is calculated off a unit of percentage error anyways as the gas mix ratio is never exactly what stoich says it should be because the combustion process never yields an actual stoich burn.

OP, you can run either straight meth, water or a mix of both. What ratio is entirely dependent on what your testing shows as most beneficial.

It will also change what the actual O2 reading value is in terms of lambda calculation. That means for those guys calculating an extrapolated A/F from a gasoline scale, or Lambda, will be skewed by the addition of another combustant with a different A/F ratio. How much you add, as a percentage of mass of your fuel mass, determines what the actual resultant value is.

Does it really matter in the grand scheme of things? No. It will run best in an A/F ratio range. That is all you really need concern yourself with. Look at it like this, you go to the track, find a command A/F & timing along with a given mass of what ever mix works best & it runs the best time: Does it matter really what your A/F ratio monitor says? Not really. It only matters in the world of comparative data. This means for you later & other guys trying t compare your data to their own.

You're missing the point... (which again I dont' claim is right)

The mass of air compared to the mass of the water is very different at like weights. The injected fluid mass is tiny compared to the air mass. In order to change the charge temp on a large scale, the fluid needs to physically come into contact with the air to pull heat from it.

I'm at 50,000:1 ratios with the amount of fluid I spray. IMO, The water/meth molecules can't physically touch a large enough percentage of air molecules flying by to pull a significant amount of heat from the aircharge as a whole.

this conversation is way out of my league! how should I tune this thing on the dyno with meth to be safe? running it pig rich doesent sound like a good idea but i dont want a pump failure to cause me to burn the motor down either

Back to back runs on a dyno is the only way to get the data you seek, or better yet take it to th struck for real world numbers. Run it at an acceptable tune then run it again with the water/meth activated to see where it lands, in comparison. Then you know the difference between the use or non-use.

You can change the command A/F or timing but then you are dealing with an artificial safety margin at this point. How far you are willing to fudge this is up to you. At the end of the day it is your car & your money. Run it where you are comfortable with.

It’s over my head as well! Just making it up as I go along trying to use common sense. (which isn’t always right) Very few have actual data that’s worth a damn since they can’t grasp IAT sensor readings are generally useless. You’d need to run a MAF or have some way to calculate the increased/decreased airflow with the meth/water on/off. Then you’d need cylinder transducers to measure cylinder pressure differences, and EGT’s to monitor exhaust temp’s.

Anyway…

I don’t think meth injection is any less reliable than a standard fuel system if setup properly. What happens if a fuel injector clogs partially? Or fuel pump flow drops off at WOT? Those will take out a motor as well if you don’t have safeguards in place. Most new ECU’s have some sort of AFR vs Load safety system. I believe the AEM wideband also have something similar. Meth injection or not, you should have something like that setup IMO. I have my target AFR setup at 10.8 above 20 psi. If it leans out past 11.2 the ECU drops the ignition and boost.

If you’re not using the meth/water in massive amounts for octane/detonation prevention, you’d most likely be fine if it failed. I spray a 7gph nozzle at the TB and a 2gph nozzle pre-turbo @ 200psi (about 12gph). This is 50/50 with E85 and an A2A IC. I can make a pass with or without the meth inj. I like my plug readings better with it on. Near as I can tell I’m making the same (if not a little more) power with less heat in the CC. That’s always a good thing in my book.

The max power rich to max power lean window for e85 is huge. About 10.5-12.75 (on a gas scale WB02). Which theoretically means any mixture in this range should be within a few % of max HP. Race/pump gas window is tiny by comparison at 12.5-13.25. So running “pig rich” hurts performance much more.

No reason to be on the lean side of peak power IMO. Start at 10.5 AFR and a silly low timing number (like 8-10* above 5psi). Then dial up the boost to where you want it. Next lean the AFR slowly until you stop picking up power. Stay within the E85 peak power “window”. Personally I’d run it rich to allow for some cylinders being leaner than others. At this point you should pull the plugs and install a fresh set. Make a pull and see if you have any excessively lean looking cylinders. If not, bump timing up slowly and monitor your gains. Gains should be pretty linear. As soon as the usual gains start to taper off , stop adding timing. Install a new set of plugs and get another plug read. Fine tune form there.

In this specific case, mass and weight are interchangeable, so you might as well say that the conversions are by mass.

Your second bold statement is volume, not mass. That conversion isn't even close. Your AFR ratio would be way below 1:1.

And you're right, water won't flash or boil until it gets into the CC, which is why I said methanol is the better charge cooler. Methanol will flash below most ambient temps, meaning that when it evaporates it can cool to far below ambient temps.

I am gonna disagree here. Try running a hot air turbo setup down track for 13 secs and watch what charge temps do at 15 psi. Then record what it does with 50/50 water meth with a 6 gph nozzle. Report back lol

It does work very well


And water will flash under 212 deg. Lol our atmosphere has water grains in it and its between 40-90 deg f typically on earth. Lol it dries up after it rains dont it

If we look up “Air Fuel Ratio” by definition, this is the very first line…

https://en.wikipedia.org/wiki/Air%E2%80%93fuel_ratio


Weight and mass are not interchangeable. Especially when we are trying measuring the ability of a fluid to draw temperature from an air charge.

For example:

Say we have a 10X10X10 room full of air. (1000cu ft) Going by weight, this would amount to 80lbs of air at standard temp/pressure.

If I were to dump an 80lb bucket (10 gallons) of water into the top of this room. What do you think it will do to the temperature as a whole?

Now if I were to fog 80lbs (10g) of water into the room what do you think it would do the temperature as a whole?

Could do the same test with straight methanol…

Going by your Mass and Weight are the same theory they would both have the same effect. (Since they both weigh the same) Which we know isn’t true.

Using the same example now with a 50,000:1 ratio of fluid to air (like my water/meth kit sprays) It’s like taking that same 10x10x10 room and misting .15 gallons of fluid into it and expecting a massive change in temperature. I don’t see how it’s possible.

What/who are you disagreeing with? Works very well compared to what? How would you measure the charge temps?

I never said “it doesn’t work”. I’m saying at the typical volumes used it doesn’t cool the charge anywhere near as good as properly spec’d intercooler would. That’s a fact.


How much time does it take water to evaporate at 40-90*? What your saying isn’t relevant. We are talking about water flying by at 200-300+ FPS in a sealed pressure system. It’s not going to magically evaporate/flash between the injection point and the CC at those speeds IMO.

:corn:

I know. I am tempted to say there is a confusion between mass and density but I am relying on physics lessons from long ago so I will try to stifle myself.

?
I quoted you stating these meth kits do little to change charge temps. I disagree with that. My own test example provided shows why i disagree. I urge you to try it. Its not even a big nozzle and its cooling the charge. Iat sensor way upstream of injection point is the measurement instrument

Can it cool better than intercooler? 100% meth in large amounts may very well do so. How many alcohol cars have you been around? After a dyno pull on a carbed methanol fueled car, the intake manifold is sweating. Its ice cold and causing surrounding air to reach its dew point. Thats very impressive cooling.

Granted thats using meth as majority of fueling, but shows it can go below ambient by large margin. Air water coolers with ice can get close to that but lot extra weight





Not all will flash but some amount def will, even at those velocities. Key is the nozzle spray pattern and droplet size when it atomizes

This is a no stifle zone! My feeling won’t get hurt I promise. I appreciate all the comments. I have zero physics back ground (I’m sure it shows) so please chime in. I’m not claiming anything I say isn’t total BS. (I’m sure some of it is!) Just discussing and trying to understand with actual data/physics instead of believing the band wagon/vendor hype on these “Alky kits”.

I have installed/tuned/tested many alky kits over the past 8-9 years. I’ve “tried it” a lot. That doesn’t mean the benefits were due to charge cooling. I believe they do little for actual charge temps, I didn’t say there were no performance benefits. Though I’ll agree the charge cooling benefits are greater on a hot air car than they would be injecting post IC and even more so injecting pre-turbo without an IC.

Your example using 50/50 and an IAT sensor doesn’t provide any useful data about the actual charge cooling. There is no way to shield the sensor from the fluid, making IAT sensor readings useless.

Common sense suggests (to me anyway) that 6gph (.1 GPM) of fluid isn’t cooling charge temps as a whole very well. Think about it…

Say you run an 11 sec quarter mile and your alky is on for 10 seconds. 6GPH is a .1 GPM flow rate. That’s .0016 of a gallon per second or .016 of a gallon per 10 sec pass (60cc). I don’t see 6cc of fluid per second putting a huge dent in the air charge temps as a whole. The same 60cc is then divided into 8 cylinders. So 7.5cc per cylinder assuming equal distribution. (unlikely)

I believe once the 7.5cc of fluid enters the CC, the “magic” happens. In the CC water can instantly vaporize and pull out large amounts of heat, and methanol can slow the flame front down. I think this is where the majority performance benefits come from. (which I have no proof of)

At the tiny volumes these alky kits spray, they absolutely can’t cool as well as a “good” intercooler. At massively higher volumes, Kevins setup on the YB link I posted proves it can have a drastic impact on temps and mass flow. He has data indicating the mass air flow increased spraying large volumes. He was injecting roughly 3 gallons per min of straight methanol compared to your .1 GPM of 50/50. That’s 30x the volume. It’s safe to say none of the “Alky kits” on the market are using that kind of volume. The large 300psi recirculating alky pumps max out .5 GPM (@200psi) and pump much less at the advertised 300psi. (they don’t even list the amount it’s so small)

I’ve been around a few alky cars. People need to understand the difference between frosty pipes and frosty charge temps. A frosty intake/charge pipe does not indicate the air charge is anywhere near the same temperature. The charge temps will always be MUCH higher. The frosty pipes are a result of many fluid cycles pulling heat from a relatively small surface area over time. This is also a waste of energy that would have been better spent cooling the CC. There is only so much heat that can be pulled from the air charge in the fraction of a second it takes the air to be ingested and expelled by the engine. The charge pipe/intake surface area is there the entire time the engine is running so is repeatedly having heat removed from it, that is why it frosts. This does not mean the charge temps are below ambient. You can have 300* charge temps and a frosty intake.

I think you confused yourself. You said:

To which I said, that is a measurement of volume, not mass. You used cubic feet for your units. That is not mass or even weight, but volume, which was incorrect.

And for your fog vs liquid water statement, that was a pretty poor example. They would have both the exact same mass and weight. 10 gallons of water turned into fog will still have the same weight and mass as 10 gallons of liquid water, you just changed the state of it. 50 kg of fog is still 50 kg of water, not matter how much physical space it takes up or how much volume it occupies, it is still 50 kg of mass. The mass doesn't change.

Both the 50 kg of fog and 50 kg of water would have the exact same cooling capacity, even if they cool at different rates, its because of dispersion and nothing to do with the volume, mass, or weight. You don't change waters specific heat capacity just by misting it. It will still take the exact same amount of energy to raise the temperature of that 50 kg of water by one degree whether its mist or a puddle.


Read up on mass vs weight. Yes, they are not the same thing. But as long as we all stay on earth, they are measured identical. This is why there is a direct conversion factor for kilograms to pounds. 1 kilogram of mass on earth results in 2.2 pounds of force between the mass and the earth, so we say it weighs 2.2 pounds. If you were to take 1 kg of mass to the moon and re-weigh it, it would not weigh 2.2 pounds. But since all units of mass were based directly on the earth's gravitational pull, then as long as we aren't talking space travel, mass and weight in this situation are the same thing. The formula for Weight is Weight = Mass x Gravity. Since Earth's gravity is a constant and is what our perception of weight is based around, the formula becomes Weight = Mass x 1.

You need to read the whole paragraph not pull sentences out of it.

I said:
I was using volume to simplify, which would then need to be converted to mass as I said. I was simply trying to explain for each single unit of fuel you need 14.7 units of air. Which is true.

If you know the volume and the density you can calculate the mass.

http://www.smartconversion.com/unit_...alculator.aspx

The max potential cooling energy isn’t being debated. 50kg of water in “fog” form will have a much greater effect on charge temps than a solid stream of water at the same weight. The less dense fog “mass” is able to physically contact more air which allows it to pull more heat out of the air molecules.

Depends on the setup, it is like saying you put 93 in the tank but really get 91, will it still run.

Well, sometimes. depends on the setup, myriad factors.

In my opinion, I would not run a high power (expensive) setup without an E85 content sensor and intimate programming.

more info:
water helps control temperature, it is recommended you keep the temperature of [air and fuel and exhaust] low when squeezing for max performance i.e. water/ice intercooling and methanol/water all seek to accomplish this. The opposite is true for economy situations. If your setup does not need "help" holding down temperature, the additional water is probably unnecessary. To confirm diagnosis, you would run an EGT sensor and shoot for a very reasonable EGT.

I wouldn't put alot of trust in those sensors to control fueling.



E50 is essentially the same octane as E85. Its nothing like 93/91. Its more like 95.6 VS 95.8. According to the Delphi Research paper anyway.

well, it isn't just the fluctuation to the octane, there is also a change to the final a/f ratio and thus final EGT may climb in conjunction with the slight reduction in octane. As to the sensor, I would certainly use a high quality OEM unit from a manufacturer which supplies sensors that offer 100,000 or 200,000 miles of average use in production vehicles.

Anyways, I mean only for high dollar setups. If you have a JY turbo then monitoring concentrations for your OEM longblock is just silly- you arn't going to push big kind of boost on a cast piston if you expect to keep the engine healthy for long, and that is one of the benefits of using Eanything is the increased boost headroom, it is similar to a racing fuel.

Some of the guys I know don't always have access to e85 so they keep the method handy for their 93 tune. But while running e85 no.
Take my thoughts and all others with a grain of salt, because ultimately, its your tuner you should listen to

This post isn't directed at anyone, I just wanted to highlight something I think is interesting.

The benefit is to injecting water OR alcohol (as you are able to inject 100% water or alcohol) is not directly due to the IAT (you are not seeking an air density benefit) but rather its ability to hold down EGT (combustion chamber temps) which directly influence detonation/octane threshold.

IN other words, the power of injecting water is in it's heat capacity of vaporization, that is, its ability to absorb and carry away temperature as it evaporates. Any IAT drop is just a coincidence/icing on the cake.

I think this is a profound understatement. I too was under the impression that the whole point of water/meth inj was to lower IAT's. My IAT's are only 120-130* in summer heat. Right now with ~40* ambient temps my IAT's are only 50-60* Based on this I didn't see a reason to run it. However, I'm learning now that the "magic" happens in the combus. chamber. So, I SHOULD run the system despite what the IAT says correct???

you sort of answered your own question, that is, the "magic" occurs in the combustion chamber. So following this logic, we want to measure the temperature of combustion to determine if we need to spray water. How close can we get to the chamber? A well placed EGT sensor right off the exhaust valve I suppose, without spending gobs of extra money throwing it into the chamber directly. So to answer your question with your own answer: What is your EGT coming off the head? DO you need to spray water to keep it reasonable?

You are correct in that, using IAT to determine whether EGT is safe, is not going to work, it might seem more clear now than it did before. Also it should also be clear that, if the IAT is 120*F, and the water is 120*F, thus no change to IAT, there will still be an EGT lowering effect in the combustion chamber as the water moves from 120->212*F+ in this example it will absorb energy.

And if you do not HAVE an EGT sensor, as I infer, then I would say yes continue spraying water if for no other reason than the cleaning benefit, I might regularly spray water into any combustion engine I own to keep the chambers clean. There are other indicators that you might need water (if the octane is low, if the engine is excessively heating up/heat soaking, I would need to know your exact situation/engine before being able to "magically" tell you if you need water or not) so pay close attention to how the plugs look, and what your knock logs look like (are you taking logs? Have you ever seen them show "knock"? Have you ever put lower octane fuel in the engine and seen the knock counts increase? In other words, have you verified the knock sensors are actually working properly, and do you see any signs of problem on the plugs)