race gas mixing and jetting changes?

[masterblaster]

Im wondering what octane rating would be as far as cost to mix 2 gallons of leaded 110 at 6 per gallon with 3 gallons of 93 at 2.40

compared to just running 5 gallons of av fuel at 3.90 a gallon what would be better?

lastly switching between 93 oct and one of the 2 above fuel setups,is there any need for jetting changes.I will be running a 93 oct motor that will be fine in the surf with 190 to 195 comp but will need 100 oct or better for flat water runs through the switchbacks in the reeds.

 

[Freakrider]

race gas burns hotter (BTU's) than avgas....in fact avgas is 700 BTU's less per gallon than pump gas with up to 10 % alcohol.....hence race gas = more power...read Group K article on avgas to understand why...

Here is the BTU energy content per gallon of the following fuels.

Regular Gasoline 125,000
Ethanol 84,600
10% Ethanol 90% Gasoline 120,900
AV fuel 120,200
85% Ethanol 15% Gasoline 90,660

 

[masterblaster]

yea ive read the less energy stuff about the av fuel having less of the heavy ended molecules,and needing slightly larger jets,but ive also known others to run it with the same jetting as prev fuel,with more comp and more advance and still made great power with no det,just some small changes in high and low screws.Mixing av gas and 93 pump seems to be what some others are doing.