In-tank meth to WMI to in-tank meth tuning woes

[BuddySpeed3]

Are there any dyno proven values for in tank methanol? I'm running 1 gallon and was able to get away with 16* at 6k rpm holding 18.5 psi on k04. I tuned for what was in the tank and used WMI for more safety and consistency. Weird thing though, I recently turned off the WMI to verify my tune doesn't knock and I started seeing knock values at 5K. Idk why it would suddenly start doing that when it didn't when I was tuning for it. Also I've always been putting a full gallon in every fill up at empty, so there would always be residual meth in tank so I was usually just slightly over 1 gallon.

[Enki]

...Because spraying meth is just as effective as adding it to the tank as far as knock reduction goes? Fuel is fuel and it all goes to the same place.

[BuddySpeed3]

Originally Posted by Enki ...Because spraying meth is just as effective as adding it to the tank as far as knock reduction goes? Fuel is fuel and it all goes to the same place.

That's true, but I tuned for what was in the tank with no knock, and then turned meth kit on. I then recently turned it off and found knock values at 5 k consistently. The temps were the same. It's weird because over the past couple fill ups, I've always been adding 1 gallon which would put me on the higher side of meth percentage in tank. I had to detune to 14* at 6k instead of where I was at 16*. bad batch of gas? Switch over to summer grade? as I noticed LTFT's became rich suddenly? Or maybe methanol doesn't mix well? Idk. Maybe injector seals. The temps were pretty cold out. Like 8 degrees Celsius. I might have to start the timing from scratch with 2 gallons per tank lol.

[Enki]

I don't think there's a grade change in methanol as a race fuel.

As far as temps being the same, there are other factors like baro pressure, humidity and density altitude (which factors all that in). Having water vapor in the air can reduce combustion chamber temps and reduce cylinder pressures.

Also, I wouldn't normally consider one gallon of anything to completely eliminate knock. What AFRs and IDCs are you seeing?


Edit:
This should all actually be in a new thread IMO.

[phate]

Originally Posted by BuddySpeed3 Are there any dyno proven values for in tank methanol?

Not really, but I suspect that once you have sufficient octane with any fuel type, that MBT values on a given engine will be within a degree or two. The big takeaway from this thread, to me, is that there is HUGE variance in MBT curves between engines. I would take the lowest values and use them as a guideline until you are able to tune on a dyno and sufficiently quantify what a degree or two of timing does for power. Street tuning is not accurate enough for that fine of tuning.

Originally Posted by BuddySpeed3 I'm running 1 gallon and was able to get away with 16* at 6k rpm holding 18.5 psi on k04. I tuned for what was in the tank and used WMI for more safety and consistency. Weird thing though, I recently turned off the WMI to verify my tune doesn't knock and I started seeing knock values at 5K. Idk why it would suddenly start doing that when it didn't when I was tuning for it. Also I've always been putting a full gallon in every fill up at empty, so there would always be residual meth in tank so I was usually just slightly over 1 gallon.

I would go back and have a look at those data logs for comparison, specifically temperatures. Agreed with Enki, this part of your post is best found in a new thread.



@SofaKingAwesome, can you copy posts 155-current to a new thread, titled something like "in-tank meth to WMI to in-tank meth tuning woes"?

I'd like to leave posts 155 and 159 in this thread, because they do pertain to the original topic.

Is that all possible? ♥

[BuddySpeed3]

Originally Posted by Enki I don't think there's a grade change in methanol as a race fuel. As far as temps being the same, there are other factors like baro pressure, humidity and density altitude (which factors all that in). Having water vapor in the air can reduce combustion chamber temps and reduce cylinder pressures. Also, I wouldn't normally consider one gallon of anything to completely eliminate knock. What AFRs and IDCs are you seeing? Edit: This should all actually be in a new thread IMO.

That makes sense, I will need to do some more experimenting as the weather warms up to get a full grasp on what I can get away with safely with higher BAT's. I don't have a fail safe, so the plan has always been to tune for only what's in the gas tank.

I'm seeing injector duty cycles peak at around 80%, boost WAS at 19 psi tapered to 17 psi at red line. Intake temps at around 50-60* Fahrenheit. AFR's at 11.6 with a taper starting at 5K down to 11.2 at red line.

Timing @ 19 psi was:
3000 rpm: -1*
3500 rpm: 4*
4000 rpm: 8*
4500 rpm: 10*
5000 rpm: 12*
5500 rpm: 14*
6000 rpm: 16*
6500 rpm: 17*
7000 rpm: 18*

"Detuned" to 18 psi with this timing curve, which yields no knock @ 5K with WMI turned off:
3000 rpm: -1*
3500 rpm: 3*
4000 rpm: 7*
4500 rpm: 8.5*
5000 rpm: 10*
5500 rpm: 11.5*
6000 rpm: 13*
6500 rpm: 14*
7000 rpm: 15*

Definitely doesn't pull as hard.

It's funny because, last summer was hot, and I tuned the car for 94 pump gas only, with timing 1* higher than my current detuned timing from 4k - 7K at 18 psi with no knock.

I did several 4th gear logs to verify no knock. I then thought it would be a good idea to turn WMI on which was fantastic. As winter temps came around, I thought I'd turn off WMI because BAT's where nice and cold, and it started knocking like crazy. I had to detune significantly to stage 2 OTS timing.

My guess was that Winter grade gas with it's lighter elements was causing knock for that tune, and that the summer grade 94 was just better quality gas in general.

So at the end of the day, I need to figure out what I can get away with safely. I know that the colder temps will increase cylinder pressures significantly as there is much more air and fuel being ignited. So running too much timing in the winter can cause fuel injector seals to leak. This may be why I was getting knock values at 5K. Not sure though. I will be investing in CPE safe seals soon.

It's just confusing because my car seems to like a certain ignition curve one day, and dislike it the next. But like you said, air density, temperature, and all that jazz comes into play when it comes to detouring knock, and it may be that I am on the threshold for how much I can get away with safely for what is in the gas tank. I may just have to start running 2 gallons of in tank meth to be 100% sure that the octane is there. It appears that there is no such thing as too much octane for these cars.

On a side note, would you happen to know if MBT changes with different alcohol percentages, boost levels, and AFR's? I read somewhere that higher boost pressure increases flame speed, and that alcohol and rich AFR's burn slower. The reason I ask is because if we taper the AFR at high rpm's, doesn't it make sense to advance the timing slightly more to accommodate for the richer slower burn rate? Idk I'm rambling again.

[sheston]

I run 2 gallons of Meth per tank and I can probably run past MBT without knock.

I think the big difference between spraying and in tank Meth usage is the cooling factor. In tank you can control it better and it's consistent, spraying is a little harder and if you don't spray above a certain CFM..... anyway, you get variations.

I use Meth in tank because I find it more consistent and better than the same amount of Eth. I also only need to get one extra fuel and can spray as well.

In Texas, it's hard to beat the cooling from spraying

[BuddySpeed3]

Originally Posted by sheston I run 2 gallons of Meth per tank and I can probably run past MBT without knock. I think the big difference between spraying and in tank Meth usage is the cooling factor. In tank you can control it better and it's consistent, spraying is a little harder and if you don't spray above a certain CFM..... anyway, you get variations. I use Meth in tank because I find it more consistent and better than the same amount of Eth. I also only need to get one extra fuel and can spray as well. In Texas, it's hard to beat the cooling from spraying

Yeah I hear ya, WMI and In tank meth are a nice combo especially for those who don't have access to e85. And it doesn't vary in "quality" throughout the year like e85 does.

I did notice my fuel economy drop when adding 1 gallon. I can imagine it would drop even further with 2 gallons. But if your getting good knock protection with 2 gallons, I may have to go that route.

I also noticed you are on K04 with built block. Ever considered a bigger turbo? lol

How long have you been running 2 gallons? Any side effects to the fuel system due to methanol's corrosive properties ?

[BuddySpeed3]

Originally Posted by phate Not really, but I suspect that once you have sufficient octane with any fuel type, that MBT values on a given engine will be within a degree or two.

Really eh? So do different boost levels effect where MBT lies? Along with different AFR's?

I would imagine these factors change the rate at which the fuel mix burns/expands?

[phate]

Originally Posted by BuddySpeed3 Really eh? So do different boost levels effect where MBT lies? Along with different AFR's? I would imagine these factors change the rate at which the fuel mix burns/expands?

They do, but it might be a much smaller change than you think. I've tested the AFR vs MBT on a dyno and MBT shift was negligible, as was power change.

[BuddySpeed3]

Originally Posted by phate They do, but it might be a much smaller change than you think. I've tested the AFR vs MBT on a dyno and MBT shift was negligible, as was power change.

Interesting, but which AFR's did you test? I read that anything in between 11:1 and 12:1 generates little changes to power output. I also read that anything more rich or more lean will cause the expansion of the fuel mixture to slow down. I'm wondering if the lack of change in power from 11:1 and 12:1 is due to direct injection and how fuel is injected at such a high pressure.

The thing that I'm also curious about is how drastic the MBT shift would be for people running over 30 psi of boost at a given AFR. I read that more boost increases the rate at which the fuel mixture burns due to the molecules being closer together, allowing them to transfer "heat" faster.

I also read that alcohol such as ethanol and methanol burn slower than pump gas, which theoretically would shift MBT at a later crank angle if using a timing curve from a pump gas tune, which in essence would yield slightly less power.

But like you said, the MBT shift would be minimal. But there's got to be some more science behind the difference in MBT with people running 18 psi, and people running 30 psi at the same AFR.

Thanks for the knowledge!

[Enki]

Originally Posted by BuddySpeed3 I also read that alcohol such as ethanol and methanol burn slower than pump gas, which theoretically would shift MBT at a later crank angle if using a timing curve from a pump gas tune, which in essence would yield slightly less power.

If my memory is correct, this only applies when in open air at atmospheric pressure. Compressing the mixture speeds up the flame front drastically, which would explain why there's little to no power loss between E85 and pump 91 at the same airflow, Lambda AFR and timing levels.

[sheston]

I've run for a little over a year and a half. No problems

I'd love to go BT. For me that would be a GTX2867R or similar. I love the almost instantaneous torque, and that would let me hold it to redline (28 psi til about 4500 now)

[Enki]

I will forever preach the EFR gospel. A local got my old 6758 turbo, which went from .65 to .85 AR hotside and it didn't lose any spool. It was already a 400 WHP turbo on stock MAP.

[sheston]

I've started looking into those. May be one in my future.

Thanks for the info

[BuddySpeed3]

Originally Posted by Enki If my memory is correct, this only applies when in open air at atmospheric pressure. Compressing the mixture speeds up the flame front drastically, which would explain why there's little to no power loss between E85 and pump 91 at the same airflow, Lambda AFR and timing levels.

That's interesting. It's nice to know that we can add octane without losing power at a given boost pressure, afr and timing curve. I went with 2 gallons of in tank meth today and was able to get away with my desired timing curve at wot. Gotta get my vvt done, then clutch, then injector seals, then bnr s4. It's gonna be a good time.

[BuddySpeed3]

I started noticing a problem when mixing 2 gallons in the tank.

Firstly, using the fuel mix cheat sheet I made the correct changes to the fuel injector scalars and fuel gravity tables in ATR.

Then, with the tank at empty, I went to the gas station, poured 2 gallons of methanol into the empty gas tank, and then filled the rest up with 94 pump.

Then, before starting the car, I re flashed the updated map. I started the car and took off. Over the course of about 10 kilometers, my LTFT's were set and were very close to zero. So very good in my eyes.

As the weekend progressed and I got to a 3/4 tank, I decided to take a look at my LTFT's again to make sure everything still looks good. To my surprise, my LTFT's were very rich. -5.6 to -8.4 at times at various break points, essentially pulling fuel in general.

I started thinking that this may have been due to the fact that I always pour the methanol into the empty tank first, and then top off with 94 pump, causing the methanol not to mix properly with the gasoline and or get used up first if it settles at the bottom. I am not even sure how well methanol and gasoline mix. (I know the 94 I use contains 10% ethanol)

I'm kind of at a loss for what to do next. It's weird that the fuel trims were spot on at first. And then as the gas tank got to 3/4's, the ECU started pulling fuel as if the methanol in the tank was no longer there.

Any thoughts? Should I change how I fill up? For example, fill the tank halfway with pump, then add 2 gallons of methanol, then fill the rest with pump to aid in proper mixing?

[gdawg25]

Your fuel trims aren't going to settle after only 10km. - 5 to - 8 isn't all that bad either. I say give it more time and see where your trims are at.

[sheston]

I do it the same way. When I read empty, I go to the gas station, add 2 gallons of Meth, then top it off with 93

I agree with @gdawg25; I think you just looked at your TRIMMs before they started to "learn", then after they started to compensate. I remember having to play with my MAF cals, since the Meth brings some of it's own oxygen or something like that....

[Enki]

Trims aren't that big a deal so long as you're hitting your WOT targets. Also, trims can change due to any number of factors, including elevation, humidity, dog piss on your wheels, etc.

[BuddySpeed3]

As with e85, does In Tank Methanol cause excessive fuel dilution in the oil? Ever since I started using it, I'm getting a beige milky colored liquid coming out of my OCC when I drain it, and it literally smells like alcohol.

When I ran straight 94 Octane and drained my OCC, it was a dark oily liquid that smelled like gas instead of alcohol. The beige color makes me think of moisture, which is not good. Although I run WMI with a 50/50 mix and a small nozzle, I'm not always at WOT. Maybe moisture in the oil comes from the WMI kit?

I actually think, alcohol is diluting into the oil. Is this something to worry about? As in doing oil changes at shorter intervals?