Hi all -
On a stock engined (stock cams, stock compression, no NOS, no turbo) bike, generally, a Hayabusa likes a bit of additional ignition advance.
For minor proof of that, when you install a "TRE" or "TEKA Fire", you notice a boost in power when you ride your stockish engined Busa.
Adding 4 degrees of additional advance will snappen up the throttle response (translate that into better power at part throttle). So - power at cruise is better. In theory, mileage might pick up a bit. (depending on your existing tuning quality)
Typically, I'll get only 1 to 2 True HP improvement in the upper rpm / full throttle on a stock engined Busa. That's only about .5% to 1.0% improvement, but - for $55, it's a pretty good deal, because the part throttle power improves at least $55 worth......
So, for full throttle HP, that's about $55 / 1 HP to maybe $27.50 / 1 HP, depending on your bike and test conditions.
It's different from the Power Commander Ignition Module.
$55 vs $350 Ign Module
The $55 FP Advance Kit really and truly advances the ignition timing +4 degrees (or retards it 4 degrees if you install it backwards).
The $350 PC3 Ign Module, while it displays the number "10" and will go "+10" to "-10" numbers, really only advances or retards the ignition timing about 2 degrees. (as of November 2007)
Which I am STILL waiting for "somebody else" to discover........
Of course, as always, any potential HP that can be gained with ignition timing tuning, can also be thrown away with poor fuel tuning.
If your bike is high compression (pistons and milling) or has higher dynamic compression (trapped compression as the engine is running) the more compressed air/fuel mix burns quicker and you would probably NOT need more ignition advance.
BUT - trying and testing is how you make better power.
35+ years of doing this says that - 'cause "ya never know.
What I can say is that properly tuned (or not tuned at all), properly tested (that means under load in top gear) piped and filtered and stacked Busa's like a little more timing and that it's generally a good simple mod.