87 vs 89 vs 91 vs 93

Mac_49

Member
Has anyone ran any tests back to back comparing 87 up to 93 octane to see if there's any substantial change in the 206?
 
Not each individual octane listed, but from 87 to 93 there was no change at all.
Now, I suspect you might be able to spend some time tuning to find a very slight something.
I know when compared to a local tracks spec. race fuel used for the 206, there is a slight difference in the tune.


-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Not each individual octane listed, but from 87 to 93 there was no change at all.
Now, I suspect you might be able to spend some time tuning to find a very slight something.
I know when compared to a local tracks spec. race fuel used for the 206, there is a slight difference in the tune.


-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com

Thanks for the info. Only reason I ask is we're required to only run 91 pump gas suggested from Shell stations here, but it's mainly due to helping keep added ethanol from not entering the engine using lower octane fuels.
 
In our area the only fuel without Ethanol is Hi Test lower grade May contain 10% mid is 5% I nderstand there is only two tanks mid grade is pumped from both. Be sure to pump a few gallaons into the truck to clear the hose pump and mixing manifold before filling race cans. I do a lot of Motorcycle carbs and the green meanies take over using the lower grades, that crap coats everything and it is hard to clean up.
 
The link above does not work, what makes your fuel any different I assume it is gasoline without ethanol which is available at the pumps. Uually non ethanol fuel is 91 octane and up, most of these kart engines don't even need 91, you have to go looking for fuel with lead and you are unlikely to find it. Why is Gulf Racing fuel different than non ethanol high grade gasoline?
 
We get non-ethanol 87 from Murphy's USA (Wal-Mart gas station). It's only $0.50 more per gallon than the ethanol stuff. We have never dyno'd but all the karts we race seem dead even with each other on the straightaways and it's easier on the carburetor.
 
Octane is a rating of how fast the fuel burns. Compression dictates ideal octane. More octane is only more horsepower if the gas does not have time to burn before exiting the combustion chamber. The low compression in the 206 needs nothing more than 87, but having 92 doesn't have a negative impact. You could put 110 in probably see no performance change....maybe a decrease as it my burn to fast for the timing advance.

Fuel with ethanol will actually make a little better HP.
 
An octane rating i used to determine the ability of the fuel to resist self ignition, not really how fast the fuel burns. There in all practicality no performance differences except fuels with higher octane ratings resist ignition by compression, if you use a fuel that causes detonation you will cause a performance problem and engine damage. Modern vehicle engine management system witness the knock and pull timing out until it goes away.
 
Back
Top