What kind of VP does everybody run? I know U-4 is popular, but theres the U-4.2, and I don't know much about leaded fuel, and what it does to your motor. Thanks gang!
i may be wrong but i think the 4.2 is less harmful on your motor, let cannoli the expert speak on this.
u4.2 can be left in system without damage also it has more octane than u4 only drawback is it isnt legal for AMA-the specific gravity is out of range on the high end
U4 is no more (technically speaking). U4.2 is the replacement but you still should drain it from your tank and run some pump gas through after each race weekend just like U4. Even though I sell VP, unless your being beat by 1/10's of a second at the front of the pack, you;ll probably be better off saving your $$$ by running pump gas and spend that VP money on more seat time. Now if you have motor work... well that's a different story as octane requirements are different.
that's the story but even VP is putting the warning stickers on the drums of U4.2 saying to remove it from your tank after each use.
i left this crap in my tank & it didn't hurt...sticking tongue out... ran 93 pump behind it. i don't advise this
What's your opinion on Street Blaze 100 vs regular 93 pump on a low comp unmodded motor Cannoli? Any gains to be found with it's ethenol 'oxygenation'?
never used it so I can't say. You need to understand that the highest power gains will be seen by using the lowest possible octane fuel that your motor can run without detonation. Oxygenation has it's advantages but you need to map the bike to fully see them. With some exceptions, just dumping the fuel in the bike will not give you the HP gains you would expect. Customized mapping is the way to go, and if you're going to spend the money for race fuel, spend the money for dyno time to get the most out of it. Personally, I'm a U4.2 guy. If I was more competitive, I would run MR9 but that $shit is crazy expensive and will destroy your fuel pump if you don't drain it after EVERY race!
As a general rule you would have to pump in more fuel if it's mixed with ethanol to get the same power.
I guess I should have noted that I was expecting the comparison to be based on jetting for each fuel. : ) I'm restricted to one of three fuels this year for LRRS, 93 pump from a specific station, Street Blaze 100, or C12. Ideally I'd run pump lowtest in my 9:1 GS500 but that's not legal, so I'm wondering if rejetting for the 'oxygenated' Street Blaze will net me anything over the already too high an octane 93.
street blaze 100 is no more oxygenated then pump fuel. It is basically a high octane unleaded street legal fuel. Good for turbo charged sport compacts so they can pump up the boost and high compression motors thatneed to run unleaded fuel.
That's what I thought, but VP's marketing material calls it an oxygenated fuel because of the ethanol content. Sneaky buggers... So, 93 octane pump fuel it is! I wonder if I can advance the timing enough to make it work...
