How many hours on bigger power stuff?
11-03-2015 | 08:29 AM
#81
Frank's Marine Service
Joined: Sep 2002
Posts: 11,959
Likes: 142
From: Elkton, MD
we have been running a drag car turbo LS power 25psi on E85 no intercooler w/meth as well and works great, I tried the same setup on our procharged 509 and even with the smallest jet they said they had slowed the boat down everytime the meth came on...now that was at only 5-6 psi
11-03-2015 | 08:33 AM
#82
Frank's Marine Service
Joined: Sep 2002
Posts: 11,959
Likes: 142
From: Elkton, MD
That's what scares the hell out of me and has stopped me from using it. It can certainly have it's merits, but there are pitfalls as well.
Mark brought up a great point about AFR's. Straight Methanol has an ideal AFR of something like 7 or 8:1 (I don't know for sure, but I know it's much lower than gas) When you start adding Meth, should the AFR's be brought down. If an engine does it's best at 12.5:1 on straight gas, then what would it be with some Meth mixed in? I guess that would be determined by the amount added, but is it proportional? If you added 10% by volume to the gas, then would the ideal AFR drop by .45 to 12.05:1 (10% the difference between 12.5:1 and 8:1)? I don't know the answer to that. Who does?
Eddie
Mark brought up a great point about AFR's. Straight Methanol has an ideal AFR of something like 7 or 8:1 (I don't know for sure, but I know it's much lower than gas) When you start adding Meth, should the AFR's be brought down. If an engine does it's best at 12.5:1 on straight gas, then what would it be with some Meth mixed in? I guess that would be determined by the amount added, but is it proportional? If you added 10% by volume to the gas, then would the ideal AFR drop by .45 to 12.05:1 (10% the difference between 12.5:1 and 8:1)? I don't know the answer to that. Who does?
Eddie
11-03-2015 | 08:42 AM
#83
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Joined: Mar 2008
Posts: 1,181
Likes: 2
From: Vancouver BC
That's what scares the hell out of me and has stopped me from using it. It can certainly have it's merits, but there are pitfalls as well.
Mark brought up a great point about AFR's. Straight Methanol has an ideal AFR of something like 7 or 8:1 (I don't know for sure, but I know it's much lower than gas) When you start adding Meth, should the AFR's be brought down. If an engine does it's best at 12.5:1 on straight gas, then what would it be with some Meth mixed in? I guess that would be determined by the amount added, but is it proportional? If you added 10% by volume to the gas, then would the ideal AFR drop by .45 to 12.05:1 (10% the difference between 12.5:1 and 8:1)? I don't know the answer to that. Who does?
Eddie
Mark brought up a great point about AFR's. Straight Methanol has an ideal AFR of something like 7 or 8:1 (I don't know for sure, but I know it's much lower than gas) When you start adding Meth, should the AFR's be brought down. If an engine does it's best at 12.5:1 on straight gas, then what would it be with some Meth mixed in? I guess that would be determined by the amount added, but is it proportional? If you added 10% by volume to the gas, then would the ideal AFR drop by .45 to 12.05:1 (10% the difference between 12.5:1 and 8:1)? I don't know the answer to that. Who does?
Eddie
11-03-2015 | 09:05 AM
#85
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From: chicago
I was told that while the meth raises the octane so to speak, it also slows the burn down as well, and unless your tune requires it, the gains are minimal. Kind of like putting 93 octane in a stock 454 mag, not gonna do a whole lot. So, it was recommended that in a low boost application, that normally can run fine on 93 octane, pure water, or water with a light mixture of methonal was the way to go. Now, high boost, where say C16 fuel may be needed, than higher concentrations of meth is the way to go . Apparently water itself, does an excellent job of cooling the charge, but doesnt require the fine tuning of fuel ratios, burn speeds, etc.
Just the way it was explained to me.
Just the way it was explained to me.
11-03-2015 | 09:40 AM
#86
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Posts: 4,480
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From: Tennessee
Stoich for methanol is about 6.5, but this only applies if you're using a methanol afr scale. The O2 sensor reads lambda and then converts it to afr. On the gas scale you'll still want to tune for similar gas afr numbers with the meth, but can usually pick up a bit of power by leaning it out a hair because you don't need the excessive rich mixture that you'd have with straight gas. All the water should have evaporated a loong time before it gets near the O2 sensor, and has no effect on the reading. With a good efi system, you can protect the engine just like you would with any other critical support sytem by monitoring tank level, pressure, flow, etc. and programming the necessary safeguards if something isn't right.
Eddie
11-03-2015 | 09:52 AM
#87
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From: chicago
Stoich for methanol is about 6.5, but this only applies if you're using a methanol afr scale. The O2 sensor reads lambda and then converts it to afr. On the gas scale you'll still want to tune for similar gas afr numbers with the meth, but can usually pick up a bit of power by leaning it out a hair because you don't need the excessive rich mixture that you'd have with straight gas. All the water should have evaporated a loong time before it gets near the O2 sensor, and has no effect on the reading. With a good efi system, you can protect the engine just like you would with any other critical support sytem by monitoring tank level, pressure, flow, etc. and programming the necessary safeguards if something isn't right.
11-03-2015 | 11:17 AM
#89
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From: bel air, md
Stoich for methanol is about 6.5, but this only applies if you're using a methanol afr scale. The O2 sensor reads lambda and then converts it to afr. On the gas scale you'll still want to tune for similar gas afr numbers with the meth, but can usually pick up a bit of power by leaning it out a hair because you don't need the excessive rich mixture that you'd have with straight gas. All the water should have evaporated a loong time before it gets near the O2 sensor, and has no effect on the reading. With a good efi system, you can protect the engine just like you would with any other critical support sytem by monitoring tank level, pressure, flow, etc. and programming the necessary safeguards if something isn't right.
