E85 Ethanol vs Methanol/Water injection - The search for higher octane

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Sep 5, 2007 | 09:43 AM

#16

scheides

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From: Minneapolis

Sorry I was thinking of those dual-drive-through McD's you see around now, plenty of space to let'er RIP!

Sep 5, 2007 | 04:07 PM

#17

3_diamonds_

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From: jamaica

does higher octane level mean more burning of gas?

Sep 5, 2007 | 05:37 PM

#18

prostcj

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From: Carlock, IL

Quote:

Originally Posted by nightwalker

is methanol something you can run doing auto-x, and your occasional spirited mountain run, or is it a quarter mile blast kind of thing?

not allowed in SCCA.....

Sep 5, 2007 | 05:46 PM

#19

trinydex

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From: not here

Quote:

Originally Posted by scheides

Do some research in the Alky injection forum on this site, but both E85 and alky injection accomplish detonation resistance by the increased specific heat of the fuel used. Each molecule of fuel is able to absorb a much higher portion of heat compared to gasoline. Going 100% E85 is probably cheaper in the long run, but the mileage is the killer for me. I run alky injection, and have a 1Gal container in my trunk. I refill it about once per week, driving about 50 miles per day. An intense day of spirited driving (i.e. tons and tons of tuning/logging runs) will drain 3/4 of the tank.

I use the SMC kit, but if I got a new one, would go with the new Aquamist one. No matter what you do, you will have to re-tune the factory ECU. The stock ECU is injecting a certain amount of fuel, and you're dumping extra in with the alky kit.

Research is your friend here

Search search search and read read read!

are you positive that the specific heat of the fuel is increased? much of the "cooling" benefits are from the fact that alcohol burns cooler but has a higher expansion ratio.

Quote:

Originally Posted by 3_diamonds_

does higher octane level mean more burning of gas?

no... higher octane in gasoline typically means slower burning of of the fuel, as in the flame front propagating through the cylinder. what is talked about when considering water injection and alcohol injection isn't always fair to be called octane but it is described as such for a lack of a better term and because of fairly misunderstood and already existing infrastructure/nomenclature etc.

the effective octane is increased by adding water or alcohol but this doesn't always mean the flash point of the fuel is higher and doesn't always mean the burn rate is slower. what it does eventually mean is that you can run more timing, more boost and this leads people to call it "higher octane"

Last edited by trinydex; Sep 5, 2007 at 05:49 PM.