Octane Rating of Methanol?
Octane Rating of Methanol?
(OP)
Hey guys - building a high horsepower turbo BMW and I have a few tricks up my sleeve to help spool the large turbo. I am about 8/10 finished my project, and have a full tubular manifold (inline 6), 76mm turbo, nitrous, and methanol injection. I intend to spray about 100 hp worth of nitrous (wet kit, so fuel as well) into the engine, 30 - 35 psi on turbo, and cover myself with methanol injection.
I am not willing to run straight methanol injection because of the low flash temperature as well as fumes and overall safety as this is a street car. So I am looking to go between 30 - 50% water (I currently use 50% water 50% methanol) to help with cooling the charge and increasing fuel octane.
What octane is methanol, generally? Meaning, if I were to run the car on pure methanol, which I can't due to injector size, what effective octane results? And as such, is it easy to calculate effective octane when using 93 octane gasoline, 50% water, and 50% methanol injected at a known rate (or any combination thereof)?
I am primarily concerned with the octane rating of Methanol itself, however.
Thanks!
I am not willing to run straight methanol injection because of the low flash temperature as well as fumes and overall safety as this is a street car. So I am looking to go between 30 - 50% water (I currently use 50% water 50% methanol) to help with cooling the charge and increasing fuel octane.
What octane is methanol, generally? Meaning, if I were to run the car on pure methanol, which I can't due to injector size, what effective octane results? And as such, is it easy to calculate effective octane when using 93 octane gasoline, 50% water, and 50% methanol injected at a known rate (or any combination thereof)?
I am primarily concerned with the octane rating of Methanol itself, however.
Thanks!





RE: Octane Rating of Methanol?
As methanol will burn with a VERY rich mixture, going rich can support higher effective or total compression than the octane rating would suggest.
Pure methanol at about 5.5:1 A/F ratio will suport a total compression ratio of about 20:1.
The nitrous will reduce the boost or compression you can run.
To much fuel and water can lead to hydraulic lock, but you need to be really over the top for that to be a real risk.
To much nitrous and methanol can put in enough fuel to cause so much evaporative cooling that it gets real hard to light the mixture.
Regards
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RE: Octane Rating of Methanol?
RE: Octane Rating of Methanol?
RE: Octane Rating of Methanol?