[rcrob]

Depend on whether you know how to jet a bike. If you can tell the difference between rich and lean you can get it pretty decent, to optimize it a dyno helps, but you may still need to tweak it a little after dynotuning. The big benefit is really to be able to change things quickly. You can download a map, upload it to the PCIII, try it and if it doesnt work you can change back easily or try something different.

 

[rcrob]

that first graph shows 100 hp at under 4000 rpm,you sure on your dyno?

The "100 hp" curve you were looking at is the torque curve, it's scale is shown on the right. Peak HP has not changed on the bike, they are both about 134hp. There is about a 4hp gain in the midrange, and about the same at very low rpm (although its a bit difficult not knowing where the operator started pulling (what rpm did he strart rolling on the throttle) for the dyno run). I don't know what type of fuel you are running, but he's got you a little lean at 13:1, stoichiometric is typically about 14:1 but varies a little bit depending on the fuel composition.

 

[rcrob]

It's pretty hard to calculate stoichiometric without knowing the exact composition. For instance if I were to use octane (C8H18), I would get a stoich. AFR of 15:1. Typically gasoline has the chemical formula CnH1.87n , where n is anywhere between 7 and 9. On top of that many fuels add ethanol which will change the stoichiometric ratio even more, so knowing the amount of ethanol is also important. Anything than adds carbon, hydrogen, oxygen or nitrogen will affect the AFR. So I can't say for sure if 13:1 is lean for European fuel. Typically, you will make a little more power just below stoichiometric mix because the fuel near the cylinder walls looses heat and doesn't burn that well.

 

[rcrob]

DOH! Damn the wife for switching me to decaf! 13:1 (13 parts air, 1 part fuel) is rich! I've got to stop posting when i'm tired.

 

[rcrob]

The earlier PC II's worked by fooling the ecu by changing the sensor signals so that is would richen or lean the mixture. The new PCIII's if I recall correctly don't try to fool anything, rather they convert the signal for the appropriate fueling. Its been a while since I read up on these.

Your bike will use the same amount of fuel in any gear assuming therpm and throttle openings are the same. The amount of fuel is directly determined by the amount of air flowing into the engine which is determined by the flow rate which is dependent on the rpm and the throttle opening.

I assume the techlogic vs powercomander is referring to the dynojet vs the factory eddy current dyno. As far as the FI is concerned you only need to know a couple of state variables to deterimine the amount of fuel needed at any given throttle opening or rpm. A closed loop system will measure the excess oxygen in the exhaust and adjust the mix accordingly. Many bikes simply use an open loop system (no O2 sensor).