Kwik, it’s not track-specific ... here’s how it works.
Ducati’s engine management system uses a sensor to measure engine rpm, and uses a throttle position sensor to measure how much you’ve twisted the throttle. The computer takes this information and then tells the fuel injector solenoid for the nozzle in each cylinder HOW LONG to stay open on each intake stroke and tells the ignitors HOW SOON before the piston reaches top dead center to fire the spark plug, using a crankshaft position sensor to know where the piston is during it’s compression stroke. More duration equals more fuel (and power.) A later spark will reduce knock for a given fuel octane among other things.
So for example, if your engine is running at 3,000 rpm and you move the throttle from 10% to 60% open, the fuel spray duration will change from about 4 milliseconds to 10ms and the spark timing will be retarded from 42 degrees before top dead center to 38º BTDC. But, this is only one of a large number of possible combinations.
The computer has to handle all the expected combinations but it doesn’t need to control the spray duration more precisely than a tenth of a millisecond, or the spark timing more than one degree at a time, to make the bike run well. So the computer has an injector duration look-up table and a timing advance look-up table, each with 256 data points (16 throttle openings X 16 engine rpms) to tell it what to do. These data points are initially determined at the factory by Ducati engineers during dyno testing for each engine configuration. Since the data look-up table will be different for each type of engine, a computer chip is used to permanently store this information. In prior years this chip was removable but in more recent models the chip is soldered-in.
There’s a little more to it. An engine runs differently when it’s hot rather than cold, and it’s fuel mixture is affected by the changes in air density at different altitudes (and air temperature.) So the computer makes a slight modification (trim) to the injector duration and timing data points it receives from the look-up tables on the chip - after it first checks its sensors for coolant temperature, atmospheric pressure and air temperature.
So why do you need to change the chip or replace the computer?
You need to compensate for any modification you’ve made to the stock engine configuration, adding a new exhaust system for example. You usually just need to replace the stock chip with one developed on a dyno by the exhaust system manufacturer, unless your mods are more extensive. If so, you can buy a programmable chip (FIM) that you can then modify yourself after doing some dyno testing of your own.
Or you can use a Power Commander to essentially modify the look-up table data point on the chip, much like the way the computer makes similar modifications using coolant and air temperature and pressure sensors.
For more information on fuel and ignition maps check out:
http://www.moto-one.com.au/performan...injection.html FIM vs. Power Commander
I caution you that creating fuel maps is a big undertaking, and not to be taken lightly. There is a good reason FIM charges the prices that they do for their chips and maps. It requires many, many hours with a dyno and a high-dollar lambda exhaust gas analyzer.
In fact, most people just pick a FIM map that is close to matching their set-up and then tweak it a little for special needs (if they can even do that.) Being able to read, decipher and intelligently change the maps is what it's all about. When given the ability to modify the settings, most won’t touch them.
Since most of us cannot afford the time or the special equipment it takes to do it right, the capabilities of a Power Commander (PC) is usually wasted. For example, a review of internet forums finds plenty of posts from PC owners who have all the adjustment range they need, but, seemingly, without the understanding to actually solve problems with it. They just want someone to supply them with a good map to use. Along with the PC's wide range of adjustment can come much confusion when you need to adjust every point, and identify each point's effect.
I suggest you go to FIM's website to understand what it takes to create a map. It's no secret, but you'll need to learn the principles and techniques to accomplish the same thing with a PC. Also, check out Doug Lofgren's website to appreciate the frustration that a top tuner goes through to get it right.
http://www.fuelinmoto.com.au/ http://www.visi.com/~moperfserv/ If your not intimidated yet, check to make sure you have access to an experienced tuner with the proper dyno (one that allows you to hold a rpm and load like an eddy current or the newer Dynojet 250.) Bring money. You need to be willing to spend what it takes to get it done right. If you have a Dynojet tuning center nearby, take it there first. The closer you can get initially, the better it will run. But getting it just right on takes a lot more work, and experience.
Simply downloading a generic Dynojet map has obvious drawbacks. For one thing, there's a normal manufacturing variation between identical bikes, and second, there's going to be a variation between your bike and the mapped reference bike regarding cam timing, correct TPS setting, balanced throttle bodies, fuel pressure (fresh fuel filter) etc.
In general, Dynojet has a good product with the PC. Their centers use a closed loop tuning system, where the dyno controls the load, the PC reads the rpm/throttle and the lambda probe reads the mixture at each point. After you do a set of runs at each throttle position, the software (that reads and controls the dyno, PC and lambda) calculates a new map. You then repeat the process and refine the map. Each iteration gets it closer, giving your bike a custom map.
http://www.powercommander.com/