From www.fuelmotousa.com

Because of the large amount of questions I receive about the O2 sensors and all of the incorrect information we have seen on the 07 Harley EFI, I will further explain how the closed loop EFI system works on the Harley Delphi system and why Dynojet has developed the Power Commander with O2 sensor eliminators. First I will start by explaining how the narrowband O2 sensor works. Keep in mind the O2 sensor is only one of the many sensors which monitor engine functions in the EFI system. The narrowband O2 sensor can only accurately measure a small area within 14.7:1 stoichiometric air/fuel ratio range and works by providing a voltage signal to the ECM which then will continuously monitor the stoichiometric mid point crossover and adjust accordingly until the A/F is in the 14.7:1 range. The ECM is only using the O2 sensor feedback signal when the system is in closed loop mode. Closed loop mode occurs only under certain conditions which are light load, steady speed part throttle, constant mode under 3500 RPM's. It is only after these conditions that the will EFI go into closed loop mode and the ECM will adjust until the O2 crossover point is in the 14.7:1 A/F range. This is not at idle, not while accelerating, and certainly not at full throttle. Simply put, an narrowband O2 sensor only works for adjusting low load/cruise area and does not work well in performance applications because it can only monitor a small area within the stoichiometric A/F range. With that being said, yes the EFI can adjust itself on the 07 Harley models. That is if you consider the small amount of time it is in closed loop, and then when the ECM is able to adjust A/F it can only adjust it to 14.7:1 which is WAY too lean. For reasonable performance and drivability this 14.7:1 A/F is extremely lean and this is the reason for the 07 bikes to run very hot with poor drivability. This condition gets even worse when you change your exhaust or air cleaner. Optimum A/F ratio for cruise area is 13.4-13.6:1 and 12.8-13.2:1 for wide open throttle. When you install an aftermarket EFI module (regardless of manufacturer) you will need to eliminate the O2 sensors with eliminators that send a fixed signal. This will prevent the EFI from going into closed loop mode and you will be able to tune to an optimum A/F ratio for the bike to run properly, otherwise the stock O2 sensors and closed loop mode will try to lean the mixture within the 14.7:1 range. Even with the Harley Screamin Eagle Race Tuner in which you can retain the O2 sensors, again you can still only work within the stoichiometric range in which the O2 sensors can measure. Dynojet certainly has the technology to develop a Power Commander for the Harley models with a Wideband sensor that replaces the stock O2 sensor which would be able to tune in real time to target A/F ratios, Power modes etc.. although with the relatively simple design of the Harley/Delphi injection the current Power Commander USB is more than capable of adjusting what we need to adjust at the moment. Keep in mind in Japanese applications the Power Commander is widely used as well in EFI systems that are far more complex with technology such as Dual ECU's, computer controlled secondary throttle blades, multiple staged injectors for each cylinder, fly by wire throttle and for 2007 computer variable intake length. From our experience tuning bikes everyday we know the Power Commander is the best EFI module available and works like no other to effectively adjust the EFI in the full range of RPM's and throttle positions, including the light load/steady cruise areas. Keep in mind that our maps are developed using different modes for light load/cruise area and for upper RPM full throttle performance. We have seen excellent results on the 2007 bikes and hope this has helped with any questions.

 

Yea, I read that last week.

I emailed them but unfortunately they don't have any maps yet for the 07 CVO 110".

I'll probably end up getting one and taking it to the tuner for a custom map anyway.

 

So what that equates to is, Harley found an 02 system, that
needs to be upgraded... Just like everything else..
And pushes the PCIII...

True Harley form...

 

It's really pretty simple, depending on how you look at it. HD did not go to a feedback fuel system because they wanted to.....they did it for emissions. What they did was create a system, that under the right conditions, would be fairly clean out the exhaust, while still allowing non-closed loop operation pretty much everywhere else. Dont be fooled.....closed loop is good for emissions and driveability, but often at the cost of maximum power. If you do not mind losing a few ponies to have a wonderfully driveable fuel system, then it's probably for you. Motorcycles are, right now, still in the formitive stages of feedback fuel systems.....about where cars were back in the late 80's. Fact is, it's gonna take more than oxygen sensors to make this system really sweet.....


nogood o~`o

 

So what about the IED's for the o2 sensors to cool down the motor?

 

Just when I think I know which product to use for making my bike run the way it should (cooler), something else comes up and makes me rethink. So many products and so many people with knowledge on which is the best route to take when tuning. And each option is not cheap. Makes it hard to make a choice and stick with it without second guessing.

 

sorry double post

 

I think I see enough advertisments on TV.

 

Richard,
Step back a minute and realize HD ain't pushing nothing on you, they do what they have to in order to meet epa standards. At the point you buy it, you decide which poisons YOU want to swallow !!

 

The iEDs and the XiEDs are spliced in line between the 02 sensors and the ECM. They alter the signal from the 02 sensor making the ECM think it is creating the 14.7/1 air to fuel mixture when in fact it is allowing a 14.2/1 or a 13.8/1 ratio. It would follow of course that this again only applies to when the ECM is actually reading the 02 sensors as per the initial explanation.
In my experience, the bike runs smoother, cooler and for some reason idles better at all times with the XiEDs in place.