Racing fuel?

[Orlando]

I went to Road Atlanta, and they had a Sunoco fuel station that had HI Octane Racing fuel at the pumps. Is there anything special or different I need to do to my bike to run this fuel. Will it damage the motor by running it? Should I see a big performance change in my bike?

[TripleThreat]

I don't think it would be wise to run a motor on high octane fuel unless is has been specifically modified and dyno tuned to run on it. You will run the risk of damaging the motor.

Jeff

[Rob377]

Originally Posted by Orlando

I went to Road Atlanta, and they had a Sunoco fuel station that had HI Octane Racing fuel at the pumps. Is there anything special or different I need to do to my bike to run this fuel. Will it damage the motor by running it? Should I see a big performance change in my bike?

Ideally, you want to run the lowest octane fuel you can without it knocking or retarding the timing. (I don't believe the 675 has a knock sensor that would retard the timing, but it might) Lower octane fuel burns faster and will actually give slightly better power and ecomomy.

Higher Octane will NOT give you anymore power unless your motor is tuned to make use of its increased resistance to detonation.

you might see some gain, 2-4HP by running an oxygenated race fuel, like VP U4 or MR9. (the latter is actually 87 octane) However, without tuning, these would run very lean and eventually melt/destroy your motor. And at the cheapest, you're looking at $75 for 5 gallons for U4. MR9 is well over $100 for 5 gallons.

Long story short, octane has nothing to do with power. Compression does, and compression dictates what octane you can run. High compression motors need high octane fuel because lower octane fuels would detonate 'knock.'

[Will]

Exactly. Anything more than midgrade for the street is a waste. I only run premium at the track as a preventative measure due to the high heat involved. Midgrade would probably be fine, and premium is probably a waste.

[Agkistrodon]

I usualy run 93, however I have run sunoco 104 and it seems to make more power. I have the arrow 2 and the arrow factory tune. you guys are 100% right that high octane is for high compression motors. Have you looked at the compresson specs for a daytona? its rather high. im going to have my bike tuned for 104 to get the most out of it but I can feel the difference and the bike seems to run better.

[duk97750]

Any additional power is strictly imaginary. The fuel itself actually has less power potential than lower octane fuels. To get more power out of a higher octane fuel, the dynamics of the engine need to be changed. Newer cars can get an increase in power due to variable timing and other changes that are controlled by the ECU.