I was wondering how much 110 octane I shoud use, or how much 93 in with the 110? What is a safe mixture and how should I mix it. Separately or just pour it in the tank? Is this safe to do on our EVO's. Mid-Michigan motorplex website said that they have 110 and something else for racing. If I go I would like to try using some for racing. What do you guys think?

 

anyone, anyone?

 

The first part of the question I don't think anyone knows yet. The Factory ECU only has so much ignition advance programmed into it, so any octane boost beyond the level where the ECU gets the maximum advance is a waste. I would do a ratio of 93 octane to 110 that will get you about 97 octane. I doubt that the factory settings can take advantage of anything higher than that octane.
Easy way to do this mixing is to get a 5 gallon jug and fill it with 4 gallons of the 110. With a near empty tank pull up to a gas pump. Pour the 4 gallons of the 110 into the tank, then fill up the rest of tank with the 93 octane. The gas pumping into the tank will help mix the gas.
This is safe, as long as the 110 gas is unleaded. Don't know about MI, but around here most of the 110 race gas is leaded.

 

Hi,
Highest grade of unleaded I've seen is 104. I run either straight 100 at the track or 50-50 mixture of 104 and 93. You can just mix it in the tank.
Cheers,

 

As WTZ stated, the highest unleaded you can usually find is 104.

The only reason to run more octane is to run more boost and to prevent detonation. 18psi should be running a MINIMUM of 93. You will not gain anything by adding higher octane if you are running "low" boost. Infact it may impede it since higher octanes usually burn slower. a 50/50 mix of 93 and 101 should be fine for 19 psi, unless the EVO ECU does not have fuel maps for higher octane, that im not sure of.