home made octane boost/race gas HELP

[fastblackcar]

GOING TO THE TRACK ON SAT.
after looking on gnttype ,i want to be sure i understand this correct, do i just add 30% of xylene or toulene to my sunoco 93, so 10 gal sunoco 93 + 3 gal of xylene = 99.5 octane fuel, do i need another additive as a lube as trans fluid?

 

[Razor]

Put some Marvel Mystery Oil mixed in.. not too much.. just a few ounces.

And watch that knock.

 

[fastblackcar]

numbers game

Razor
after looking at the numbers, it should be 7 gal sunoco plus 3 gallon of xylene or toulene, to get to the 30%, how much marvel ?, 3 oz. per gallon of xylene, i seem to be running on the street with 20# with no knock, hoping to raise to 24 for the track, i will drain my gas out prior and trailer the car to the track, raining here now, may not get to test before going to the track. thanx for the help everyone........Tom

 

[Razor]

The best thing to do is buy race gas. That way you know what you have. Its been so long since I messed with xylene :redface: Dont miss pouring it in, splashing on paint, etc.. And extended use will mess up the plastic filler around the neck of the tank.

My understanding is Xylene is 118 for octane. 5 gal 93 + 5 gal 118=105.5 octane. This assummes everything mixes as should. You add more 93.. then the numbers come down. How much octane do you need to support 24 PSI.. that question you need to work up on looking at your scantool. Every car is different as to its octane requirement to run a specific boost.. and once modifications are done.. like head porting.. everything changes.