consider using toluene, as 'gasoline-like' fuel,
in any non-pump gas classification.
Tol. has an octane rating of something
near 115 or better, is a single molecule, so it would
cheat resistant.
I understand some minor changes would needed to cars,
and some additives would be needed to be added.

I don't see any benefit to race gas other than
'mental connection' to a traditonal gas station,
for spectators.

Here is a pdf listing something of a recipe
for Tracktek 111, bottom of page 1,
notice that TT111 contains toluene.

http://www.cpchem.com/msds_unsecured/Import_27760_MSDS_O_ENGLISH_A_ENGLISH_A_N.pdf#sear ch='tracktek%20111'

 

If you can buy Toluene dirt cheap then go ahead and make your high octane fuel. Most of the time by the time you've added enough Toluene to reach the same octane level as the race gas, it's cheaper to just buy the race gas.

If you're in serious competition racing then you'll buy race gas. All the race gas manufacturers mix their products to exact standards. Using a homebrew will work just as well but if you race in a class that does a fuel check, you'll probably fail. If you race in a class where consistency is the key to winning, your homebrew batch may change slightly and cause problems.

There's no more BTU energy in 92 octane fuel as there is in 112 octane fuel. Octane is the fuels resistance to detonation. It burns slower allowing for high compression or boost applications where low octane fuel would preignite before the ignition ignites the fuel.

 

This is NOT true. The lower the octane the more BTU's per gallon. In order to get the higher octane you have to add chemicals to the fuel, the more chemicals the less gas per gallon, and the less BTU's.

There is a reason we use gas in our cars. It has the most energy/gallon/cost.