I've seen a few postings here regarding the "need" for an ECU mod/replacement/chip to add accessiries to 2006 ST-3s. You don't need an ECU change to add new mufflers or a new air box to a 2006 ST-3. That's what a "Closed Loop" EFI system is for.
On ST2, ST3 and ST4 Ducatis 2005 and earlier the EFI systems were all open loop systems. In 2006 Ducati went to a closed loop EFI system on the ST-3.
Open loop means that there is no feed back to change the operation. Closed loop means you measure something and make changes based on those maesurements. In an Electronic Fuel Injection--EFI system, the loop is closed with the oxygen (O2) sensor.
For 80 or 90 years the open loop fuel system used a carburetor.
The next step, c. 1980, was/is an Electronic Fuel Injection-EFI with built-in fuel maps, i.e., an open loop EFI system. An open loop EFI will get better mileage and have reduced emission over a carburetor fuel system. An open loop system is set at the factory for how it left the factory. That's why you need Power Commanders and chips to re-map the fuel supplied when you change the breathing ability of the motor.
A closed loop system should self compensate for the breathing ability of the motor. That's what the O2 sensor is for, to read the exhaust oxygen and compensate (change the air/fuel ratio), to maintain the optimum
stoichiometric (air/fuel) ratio for any operating condition(s).
Several beneficial effects arise from a closed loop system. First, they will get better mileage over a range of operating conditions. Second, they can be better tuned for elimination of unburned fuel (and the attendant SMOG products). Third, they automatically compensate for altitude. Closed loop vehicle EFI systems will run smoother at altitude as the Electronic Control Unit--ECU meters a smaller amount of fuel to match the smaller amount of air ingested at altitude. More on 1 and 2 later.
In order to boost the CAFE (Corporate Average Fuel Economy) and meet the EPA SMOG standards, car manufacturers made the switch to closed loop systems 10 to 15 years ago. It costs more engineering time (dyno time and tweaking) to make the fuel
and air maps for a closed loop system.
By 1990 all Ford 5.0 engines had closed loop systems. For non-supercharged or non-NOx applications; new heads, cams, exhaust, intake systems, even much bigger displacement blocks all just bolted together with no changes to the computer systems. GM did the same on the 5.7 engines a little later. But now almost all car EFI systems are closed loop and speed equipment can be added on and the mixture is automagically set to maintain the correct air/fuel ratio.
Forced by various Government agencies, it is mostly for the 2nd reason (above), SMOG limitations, that closed loop systems are now making it motorcycles. Without the financial incentive (or is it a whip?) for cleaner emissions, the motorcycle mfrs haven't had the incentive to incurr the expense of going to closed loop systems. Now with the new European standards, we are seeing BMW-motorcycle and Ducati switch to closed loop systems. We are also seeing, in both cases, the result of trying to squeeze too much out of the closed loop systems, as both companies struggled in the first application to get the surging problems taken care of.
In reading the later ST-3 surging threads, it appears that Ducati may have finally fixed the surging problem and the EFI target fuel ratio is now proper across the rpm range. I could see (if the lean mixture really is sorted out in the '06 EFI system) that the late '06 and or '07 computers will be used as a retrofit kit to handle engine breathing changes. [Ford Motor Sports did sell, and may still do so, a kit to retro-fit earlier open loop EFI 5.0 engines to the later type closed loop systems.]
Lucky
ST3 buyers field tested this system for Ducati and we'll likely see the closed loop system applied to the rest of the Ducati product line over the next few years. Yes, even the streetable race bikes. Some mfrs factory race bikes have closed loop systems that are now integrated with other sensors to manage power application in maximizing traction. They don't have to worry about SMOG, but they do pay attention to fuel economy.
So, there really may be an upside to all these '06 closed loop surging problems. You'll probably get better mileage and not have to worry about spending money on ECU changes when you upgrade exhaust and intake systems.
Yes, this will hit the EFI/ECU tuner market and they may eventually move on to other fields, just like what happened in the automobile market.
Linear Mode
