Methanol octane rating

[-DSM2NR-]

Quick question. I'm getting a methanol kit. How much octane points will the methanol raise the fuel? How much will a 50/50 water/methanol mix raise 91octane.

 

[JayRolla]

I heard its equal to 106-110 but it actually dont raise the octane it just takes away detonation. Pretty much the same thing.

 

[-DSM2NR-]

I'm pretty sure it does raise octane. That's why you don't really need to buy racegas when you have a methanol kit...

 

[Dark_Horse]

As a general rule a 5% mixture of methanol will raise octane by about 1 - 1.5 points. So a 50/50 mix should equal about 100 - 105 octane (figuring 91 octane premium). The true octane could be much higher though...Reason below.

It's pretty hard to narrow down an actual octane rating for methanol or ethanol since the way they calculate octane is based on gasoline. Alcohol fuels have intake temperatures that gasoline fuels will never see. While octane measurements of alcohol fuels put octane between 100 - 110, the actual octane is much higher due to the higher cooling properties.

If you don't believe me, remember this: Running straight methanol (I know you're talking about meth injection) will cool your intake charge so much that you can run without an intercooler. Lets see any C16 race gas do that.

 

[-DSM2NR-]

ok, sounds good.