How much effect does the PC have on a bike? Do I need to put one on my bike if I have a better than stock air filter and aftermarket exhaust? What does the PC really do? Exactly what is "Mapping"? and how do you do it? I couldnt really find what I want with a search. Thanks for your help.:thumbup: There are no dumb questions, right?
Mapping is the computer's plot (in memory) of how much spark advance, and FI duration to apply for a given scenario..... this is determined by RPM, air temp, and throttle deflection. The air temp substitutes for air density, which changes with altitude, and temp.... thinner air won't carry as much fuel.... so if the air is hot, or you are above a certain altitude, the amount of fuel in the mix is reduced to match what the engine can actually burn.
When you reduce the intake restriction with a freer flowing air filter, and/or modified air box..... that can alter the air pressure delivered to the intake. When you also change the impedance in the exhaust, especially by removal of the cat, and add a 'straight through' muffler, vice the folded path in the automotive style OEM muffler, you can have a fairly significant effect on the amount of work lost, to breathing. Part of the 'work' you are 'harvesting', was the muffling of the exhaust noise.......
This is where most folks 'gain' a couple of ponies for all that work and money. The engine actually makes the same HP, but you get a bit more at the rear wheel. $800+ for the glass packs, maybe another $50 for a low restriction filter..... for 2-3 HP?
If you want more than that ~3-5% gain, you have to alter the fuel air mixture, to allow more gas in the mix. This is where a dyno comes into it, and the PC III/V. If you actually measure the HP at the back wheel with a dyno, you can adjust the amount of fuel to get an increase in HP. Almost all of the time, this means you have to add more gas, which decreases the MPG.
Last time I checked the PC III sets you back another few hundred dollars; and the Dyno time to make it useful will also cost you some cash. The end result of all of that, is a 'custom' map, which can be run on your bike.
By now, we're talking about $1300 or more, and it might result in no actual gains..... but done right may result in 6 or 7 HP increased, hopefully in a fairly uniform manner across the RPM band.
That's a lot of cash. And you get worse mileage, and have a good chance of annoying someone around you with the noise.
