How Much Methanol or PI for How Much Power?

[Redline]

@Enki and I were having a conversation about this, and although Ken said he didn't care about it in his thread, I wanted to clean it up anyways, so I'm moving it here:

Basically, the reason for the discussion on my end is that moving forward, I'll be looking at an EFR7163 and using methanol for the extra necessary fueling to hig 500whp at ~7,000rpms. Here's the conversation:

Redline:
I think it all boils down to the various energy potentials of various types of fuel. Typical 93, for instance, has about 30% more energy potential than pure E85. I don't know exactly where methanol fits in. There are probably over a dozen influential factors at play that neither I nor @WetzMS3 accounted for. Apples to apples only applies to completely identical setups, exactly the same ethanol mix ratios (if any), and whether pure methanol or mixed, just to name a few. Turbo selection and efficiency in the particular power range is also a factor: energy lost as heat instead of transferred to the wheels makes a difference.

 

[Redline]

My calculator says 34 GPH for enough meth for 500 to the wheels on a FWD assuming only 100% stock IDC.

With what in the main tank? Any eth? If so, what mix? What mix of methanol? What about the numerous mods that can have an impact on efficiency, such as power instead of energy lost as heat? Headwork? Many other influential factors? Not trying to convolute things; I just think it's a lot more complex than that. I went from 103-105 IDC at 385whp in ~70 ambients to 87 IDC at 385whp in ~70 ambients on a CM10 (12.8GPH). So the equivalent of 800cc of 100% methanol lowered my IDCs by ~20 points. That's pretty significant with just one CM10.

 

[Enki]

Actually I think methanol has slightly higher energy than Ethanol is, but Ethanol has slightly higher cooling. Probably wrong on that, however.

 

[Redline]

Correction: 32 GPH meth.

Full corn in the tank (E85).
12.5% drivetrain loss
M100 spraying full tilt
Enough air for 500 WHP (that's 2.112 load @ 12:1 AFR and 7500 RPM)
100% IDC max on stock injectors
5000 total CC of fuel required.

Ah, that's the difference. I don't use full corn. I use E25-E28. So I get an extra ~15% or so fueling headroom out of my stock DI system. And 3400cc stock DI system (which is ~54 GPH) plus another 1600cc of methanol (25.6 GPH) means I'll have 5000cc (~80 GPH total) anyways. Should be able to get to 525whp, maybe even more. That's the ricer math, anyways, we'll see what reality brings.

Personally, I'd never run 100% corn when I'm already spraying that much methanol. Heck, I may just go straight 93 + methanol. No need to annihilate my gas mileage and have to take the pure corn extra steps.

I'm stickin' to 500whp, though. I think the 7163 will be very happy there.
[doublepost=1479327692][/doublepost]

Same settings as before but adjusted the BSFC for estimated E25 and got 26 GPH meth. Pretty close.

Edit: It's more accurate to assume ~3000 CC for stock fuel system, according to my DW cleaning/testing sheets.

Supposedly they're 850cc/each, so 3,400 total. And if we're pushing 1,800psi with internals instead of the 1,600psi they were rated at 850 for, then the DW estimate seems low. What pressure were they tested at?

@WetzMS3 what you're saying makes sense to me. 50/50 E85 is usually about 40% methanol/volume. Since I run ~25-28%/volume, I think that I may be able to make 500whp with 2 CM10s (25.6GPH). I have an extra CM7 I could always throw in there too, if needed. It'll be interesting to see.
[doublepost=1479327717][/doublepost]

PI pressure, which is low. They do provide scaled up flow estimates though, and they aren't much over 1500. The difference 200 psi makes on a DI injector isn't much, when you're over 1600 anyways.

Their correction chart shows 850 @ 600 PSI and 1551 @ 2000 PSI.

Sounds like they're not properly setup to test true DI injector flow rates in the operating conditions our platform sees?

Let me ask you this: how many cc/min (or GPH) do we need to flow to hit 370-380whp with E25 at 6,700rpms? Then, how many cc/min (or GPH) do we need to flow to hit 370-380whp with straight 93 at 6,700 rpms?
[doublepost=1479327745][/doublepost]

http://mazdaspeeds.org/index.php?threads/enkiworks-pre-tune.3397/

380 @ 7k w/ E25: 118 IDCs or 9 GPH / 542cc extra fuel
380 @ 7k w/ pump: 97 IDCs no aux

Keep in mind this spreadsheet is ONLY for calcing air / fuel, and does not factor in things like timing / knock / etc.

So what are the total CC and/or GPH figures for these two (E25 and straight 93) @6,700?

The reason I'm asking is that we know stock injectors can carry us to 370-380whp, so I want to how what exact CC and/or GPH that translates to. With that information, then we can more accurately predict hp/cc or hp/GPH, you know?

 

[Enki]

With what in the main tank? Any eth? If so, what mix? What mix of methanol? What about the numerous mods that can have an impact on efficiency, such as power instead of energy lost as heat? Headwork? Many other influential factors? Not trying to convolute things; I just think it's a lot more complex than that. I went from 103-105 IDC at 385whp in ~70 ambients to 87 IDC at 385whp in ~70 ambients on a CM10 (12.8GPH). So the equivalent of 800cc of 100% methanol lowered my IDCs by ~20 points. That's pretty significant with just one CM10.

Same E25 in the tank (or whatever it was you stated), M100 sprayed. With that extra octane, I bet you were able to up timing a fair bit too, which can easily make up for any lost fueling/reduction in airflow. Keep in mind, my calculator is for fueling only, and doesn't account for things like timing and knock and etc.

Edit: What the fuck is going on in here lol

 

[Redline]

I'm not going to adjust it for 300 rpm, but the total for the first one would be 3000 + 542 = 3542 and for the second would be .97 * 3000 = 2910.

Gotcha. Makes sense to me, then, that 3400cc rating for stock injectors is pretty accurate,as someone who @ 385whp @6,700 saw ~105 IDC. Unfortunately, I don't have a large enough turbo to hit 385whp on 93; the S3 hotside doesn't facilitate enough timing to get there. Too much heat gets bottlenecked, and we start seeing knock.

So, if 3542/385 = 9.2 cc/hp (E25), and 2910/385 = 7.56 cc/hp. That comes up to ~22% greater injector headroom required for E25. Those numbers translate to 56.14 GPH and 46.12GPH respectively.

Just for the sake of ricer math, let's take the more conservative E25 estimate of 9.2 cc/hp (figured considering 385whp @ 7k). So if I wanted 500whp at 7k, then 500 x 9.2 = 4,600ccc is needed, which is ~72GPH. Assuming I flow 3,400cc (~54GPH), I'd need another 1,200cc (19GPH). 2 CM10s is 25.6GPH.

This is what confuses me. Seems like 2 CM10s should be more than enough for 500whp @ 7k, even with E25 in the DI system. And the limited fueling headroom of E25 has zero impact on the methanol system.

Do you see why I'm confused? Maybe the only thing I'm missing is energy potential/volume of E25 vs. energy potential/volume of 100% methanol. Does methanol have even lower energy potential than ethanol?
[doublepost=1479327814][/doublepost]

That doesn't factor in BSFC though, and that's one thing I probably need to adjust or allow adjustment of on my aux fuel calc. It takes more methanol to make the same HP as it would E25 (in your case).

Ahhh, yeah, I ninja edited right after you responded and said:
"Do you see why I'm confused? Maybe the only thing I'm missing is energy potential/volume of E25 vs. energy potential/volume of 100% methanol. Does methanol have even lower energy potential than ethanol?"

So how much more methanol is needed to have the same energy potential as E25? That would help get closer to an apples/apples comparison, I think.
[doublepost=1479328015][/doublepost]

Same E25 in the tank (or whatever it was you stated), M100 sprayed. With that extra octane, I bet you were able to up timing a fair bit too, which can easily make up for any lost fueling/reduction in airflow. Keep in mind, my calculator is for fueling only, and doesn't account for things like timing and knock and etc.

Edit: What the fuck is going on in here lol

I got on a roll because Ken said "feel free to post whatever" but then I thought it should be moved, LOL.

Another factor we didn't touch on is efficiency. It's entirely possible that the reason extra methanol is used is because someone is still on a 3" intake and 3" exhaust trying to hit 500whp. Going up to 3.5" on both should make the setup a lot more efficient and stretch the fueling headroom, I'd imagine. I'm really amazed by how many big power guys are still on 3" exhaust, honestly...

 

[Enki]

There's also wall wetting, and with meth spraying, not having enough heat in the piping can cause a certain percentage to *stick.* It's one of the reasons I'm not going to huge ass intercoolers that will keep the air temps ambient; I actually *want* a hot air charge to make evaporation more efficient.

 

[Redline]

There's also wall wetting, and with meth spraying, not having enough heat in the piping can cause a certain percentage to *stick.* It's one of the reasons I'm not going to huge ass intercoolers that will keep the air temps ambient; I actually *want* a hot air charge to make evaporation more efficient.

Indeed. Found what I was looking for. You were far too nice on methanol. It's energy potential/volume is only ~70% of E100 and a very low ~50% of E10 enriched regular fuel:


So basically you need double the cc/min or GPH of methanol to equal the same cc/min or GPH of regular fuel.

This means that my 1600cc of methanol would only effectively be 800cc, then the wall-wetting, etc., occurs, this is effectively lowered (but hard to quantify). Anyways, this adds up to ~4200cc total, at most. Yet ~4600cc is needed, so another CM10 nozzle would add 800cc of methanol, which, when considering its energy potential, would bring the total up to the necessary 4600cc.

I think the larger intake and exhaust will really help this, though. And running straight 93 instead of E25 could make two CM10s sufficient instead of 3, perhaps.

 

[Enki]

Yeah I had that backwards. Meth has better cooling then too.

 

[Maisonvi]

Well shit, not I need to subscribe to another thread just to keep learning shit. lol