Mixing "race fuel" with pump gas-

[Speeddog]

I understand the need to run leaner mixtures at higher altitudes but why on earth would octane have anything to do with that?  Octane basically deals with how fast the fuel burns and when it starts burning. Lower octane igniting sooner than higher octane and all that.

At higher altitudes, peak cylinder pressure is lower, much like with a lower compression ratio at low altitude.

[Radar]

I'm not running a 796, and I don't live at high altitude...

I'm on the West Coast... very low altitude, and I ride an 05 S4R-

I'm not sure how the confusion came about.

Sunoco has various fuels available--leaded and unleaded and oxygenated and non-oxygenated... Octane ratings start at 110-

[ducpainter]

All the altitude controversy aside...

race fuels can be very corrosive and require special care for the motor after every time it's run.

I'd avoid them for a street bike.

[Buckethead]

The only additive your gas needs.

[He Man]

im not going to lie, if you gave me a 5 gallon jug of race fuel, id drop 1 gallon for every 2 gallons of regular fuel and use it as is just because its free gas!

[justinrhenry]

The only additive your gas needs.

http://www.gixxer.com/forums/showthread.php?t=226570

[Duc796canada]

I'm not running a 796, and I don't live at high altitude...

I'm on the West Coast... very low altitude, and I ride an 05 S4R-

I'm not sure how the confusion came about.

Sunoco has various fuels available--leaded and unleaded and oxygenated and non-oxygenated... Octane ratings start at 110-

LOL...you caught that one too...I think the 796 reference came from me recommending the use of the 89-91 and I ride a "796," so subsquent postings went that way. DOH!!!

[MadDuck]

At higher altitudes, peak cylinder pressure is lower, much like with a lower compression ratio at low altitude.

Makes sense now that you put it that way.

[NorDog]

The only additive your gas needs.

I use a blend (highly secret ratio) of Mentos and Brawndo in my S4RS.  No problems so far, but it is tricky to handle.  I have to make sure I don't spill in on any grass, and to keep it away from any Diet Coke.

[Randy@StradaFab]

  I may be dead wrong but I believe detonation is more about ignition timing than compression. You can have an engine with 8:1 compression ratio and make it ping if the timing is advanced too much.

[ducpainter]

  I may be dead wrong but I believe detonation is more about ignition timing than compression. You can have an engine with 8:1 compression ratio and make it ping if the timing is advanced too much.

Not entirely.

While it's true that advanced timing can cause a low compression engine to ping...

You can retard the timing on a high compression engine and it may still ping if the octane rating is too low.

[Howie]

  I may be dead wrong but I believe detonation is more about ignition timing than compression. You can have an engine with 8:1 compression ratio and make it ping if the timing is advanced too much.

Compression ratio, timing, volumetric efficiency, combustion chamber design, air fuel ratio running temperatures, ambient air temperature and altitude will all affect detonation.

[Radar]

Good information in this thread- I appreciate all who responded.

Lots for me to learn about Ducati...

All the best my friends,

Eric M.