Wideband o2 narrowband simulator

[Wracul]

What if the narrowband stohic was 12,5afr. And could be manualy changed up or down by the user on the fly ?
With a display with both actual afr and wanted afr?

Would this solve our ecm "police" 14,7 afr issue?


I have done some research and im pretty shure i could make one of these.

 

[Sirius815]

Well - I'm not 100% sure if the 14.7 rule applies at all RPM, however if you wanted to run richer, tell the ECM the bike is running lean and the ECM will richen it up. If you tell it that the bike is rich, the ECM will compensate and run a little leaner.

As for on the fly - that's be tricky maybe. I'm running an Innovate wideband with narrowband output that is customizable.

 

[Wracul]

I have read the lc1 pdf and it look like a very nice solution to the narrowband problem. Nice to adjust the afr from pc. If combinding that analog 0-5v signal with an arduino or similar Microcontroller. I could even have the oportunity to switch to higher or lower afr on the fly. Plus the ability to read the wanted afr/lambda. How long does it take for the ecm to "learn"?

 

[XRorXB]

My background is more in automotive OBDII, but I'll take a stab. Unless the ECM is modified to expect a value other than 14.6/14.7 as stoich in closed loop, it will try and adjust you back to stoich.

Have you seen the XiED device? That kindof sounds like the idea you're talking about. It goes inline between your O2 and ECM and modifies the reference voltage so that a richer fuel mixture is used.
But in that case the ECM doesn't relearn any different than it does for your present lambda input. For all it knows, you still have a narrow-band O2 that's just reading a lean-biased voltage, so it adds more fuel to compensate. It is supposedly plug-and play.

 

[XRorXB]

To my knowledge, though, it is not adjustable as it seems you are looking for.

 

[Sirius815]

As long as the ECM "thinks" everything is okay it won't try to relearn anything. It's still thinking everything is at 14.7 remember? You've just modded the signal from the o2 sensor. Also - I doubt that this would ever work without the use of a wideband o2 sensor. You need to be able to "read" the actual afr value so that you can have your controller decide what is lean/stoich/rich and relay that over to the ECM.

Adjustability on the fly is not going to be easy to solve unless you build your own wideband controller.

 

[Wracul]

In closed loop the ecm use the o2 as reference. Ergo if people are running with the 14.7 stohic narrowband sensor. The sensor will always try to fuxxup everyones tune. It gets even worse if the ecm is ridden in the learn area.

12.5-13 afr is perfect for power and longevity of the engine. And that is not possible to get without tossing the narrowband in the bin. Like I said. The LC1 seemes like a very good solution to the 14.7 afr problem. But again it would be sweet to have the oportunity to adjust the "wanted" afr without connecting the lc1 to a computer.

Im ordering the lc1 to test it and maybe use it in my own controlable afr setup.

I know a wideband controller like the LC1 is hard to do. But im actually surpriced to not finding any codes for this on an open microcontroller platform. Have searched several hours and no code so far.

 

[Sirius815]

Good luck!

 

[Wracul]

Think i need it.

What afr ratio do you run on your bike with the lc1 sirius815?

 

[Sirius815]

Considering that the ECM likes to go back to 14.7 - 14.7 I haven't done all the tuning yet. For around town the bike is pretty well behaved (~1500-3000rpm at light throttle) on medium to heavy throttle it goes rich as **** (I've seen down to 11:1!)

More tuning is required, just haven't had the time. I'm going to try and get some dyno time to tune as I haven't had much luck datalogging on rides (engine not quite warm enough or timeout errors).

When I will be doing the tune I'm basing my afr's off the ECMSpy tuning guide going to about 13.5:1 at heavy throttle and 15.2ish:1 on cruise. Slightly lean for better fuel economy.

EDIT: Also I run the MTX-L gauge which has the LC-1 built into the gauge housing. The only downside - it's not waterproof