fred head hi octane

G

graydog8josh

Member
just ordered a 5.5 fred head.
need to run higher octane gas. I was going to buy some legit octane booster but i dont really know how much it will really raise the octane. They dont have any high octane ethanol free 87 is the best they have. So I decided to buy race gas and see how well it works. c16 is kinda expensive but its what they had. this is my before the results post, we'll see how it goes
 
Octane boosters only raise the octane by like 7 points and they brag about it on their lables... what they don't want people to know is that 7 points is 0.7 higher than it was before the booster was introduced. that's pretty much the way 104+ boasts... and most of the other brands.
racing fuel is expensive but it works...
Or you can go to your local hardware store or paint supply shop and buy a gallon of toluene and add that in the right proportions to your fuel to raise the octane to a respectable level without breaking the bank or your engine... a little google searching on the subject should get you the right mix ratios. Alcohol or even E85 has more than enough octane as well but some serious rejetting is needed before your air fuel ratio will be even close to correct.
Another option to race gas is avgas, you can get 100 octane avgas from most airports and they'll fill up your 5 gallon containers for a fraction of the price of race fuel.
 
put my new mix in 28:1 with head, and ive had to turn my mixture screw out a few turns(phbg) and it seems much more powerful and responsive. I might have needed to do that for a while though. Im watching my temp and going on a tuning run today before work. race gas 116 octane with maxima 927 doesnt smell nearly as nice as my ipone strawberry oil did in pump gas :(
 
38 idle jet 76 main jet seems to be working ok. I have a 78 main in there right now now though, and its 4 stroking a lot at hi rpms i could go leaner i think but the bike feels really smooth when its cooler
 
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