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Old 10-16-2012, 01:48 PM   #113
roger 04 rt OP
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EDIT: THIS EXPLANATION IS INCORRECT. PLEASE LOOK FURTHER INTO THE THREAD FOR A CORRECTED EXPLANATION. The error was due to an omission in the PC III Installation document that has since been discovered. Further, I have been in touch with Dynojet who have provided good detailed answers to some questions on the connection of their Wideband sensor to the Motronic that is not in any of their documentation.

Another way to add fueling to an 1150 (or 1100) is by using a PowerCommander III, block diagram below. This product includes a Wideband O2 sensor and an Add-On Fuel Table computer. It is a standard product, that can easily be added to an 1100 or 1150. Many believe that it is necessary to "Dyno Tune" the Powercommander after installation, but you could richen the mixture without having to go to that expense.

One reasonable way to use the PC III would be to install it along with its Wideband O2 sensor, use the included software to program the O2 sensor Lambda to 13.8, and fill in the fuel table with 6% everywhere, perhaps tapering off toward the high RPMs and high TPS angles. In this mode it would be similar to the LC-1 and somewhat easier to install.

With the O2 sensor programmed to 13.8, the Powercommander claims to operate its own proprietary Closed Loop program (see the shaded Closed Loop area in the second chart). That said, major parts of the Motronic are disabled when the PC III is installed, particularly the Adaptive ability. Powercommander makes no claim of Closed Loop adaptation within its module. Also, the Limp function of the Motronic is enabled when the O2 sensor input is disconnected. This means the pulse stream going into the PC III will have the 10% variation I wrote about a couple posts back.

The PC III looks pretty straight-forward to install but you do have to disconnect the O2, add two connectors to each injector, and install a piggy-back onto the TPS connector. So I would say it's fairly invasive to the Motronic system--if that matters to you. The PC gets its throttle position information from the TPS piggy-back but doesn't seem to have a TPS learn function like the Motronic. The PC III gets its RPM information from the injectors by measuring the frequency of fueling pulses. That works well but during Overrun Fuel Cutoff, the PC III doesn't have an RPM input. I think that might be a nit, but I mention it.

At its list price of $495.95, it's about three times the cost of an LC-1 but it is a Plug and Play solution. In terms of software, it's not clear to me whether the PC III has the logging capability of the LC-1 which I see as an important diagnostic tool. All the AFR charts of this thread have been made using that capability. It does come with a good suite of software for populating and managing the fuel tables should you wish to adjust them.

A further note on using the PC III for richening:

I mentioned that a simple way to use the PC III would be to program the Wideband O2 that comes with it to (say) 13.8:1 and fill in the fuel table with 6% (maybe tapering to a lower number at the high RPMs and high TPSs). However, 6% is only the right number if you're running pure gasoline.

Since I haven't seen any documentation on the PC III's Closed Loop capability and haven't measured it; and since the Motronic's Closed Loop ability (and therefore its Adaptation capability) is disabled by a PC III; I believe that the fuel table should have 10% added for motorcycles that run E10 fuel. That would be 4% for E10 and (say) 6% for the richer Lambda setting on the Wideband O2.

roger 04 rt screwed with this post 11-17-2012 at 07:09 AM
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