Digital Tuning Use wideband controller to....

[rockyracoon]

Years ago I built a 4cyl turbo mustang using a computer and motor from an 87 turbocoupe. Anyway I used a wideband controller that had an analog output to replace the stock o2 sensor signal to the ecu and was able to actually change the air/fuel ratio by installing a simulated narrowband/ bias to the signal going back to the ecu thus tricking the puter into richening or leaning out the mixture. My question is can I do this for my 95 gt ?

 

[WhiteCobra95]

I think it depends on how you do it. You definitely need cal access to the stock ECU to make it happen. The problem is that most narrow-band ECU's stop looking at the O2 sensors when they go into enrichment (open loop) at high load, and only use the adaptation values established when it runs at lambda 1.00 as a feed-forward adaptation. I don't know how you would get the ECU to modify the fueling in this situation. You could set the ECU to run closed loop all of the time and set the fueling map all to lambda 1, but then your wideband would need a speed/load based desired lambda map to target it's narrow band output in order to trim the ECU. In any case, doing this by mostly feedback control would be really sketchy.

 

[jozsefsz]

Short answer, yes, the Innovate LC-2 for example (this is what I run) has a secondary analog output that can be configured to simulate narrow-band switching. It's not a pure 'simulation' or tricking the ECU (where I think @WhiteCobra95 is heading) but rather just putting out a real narrow-band O2 sensor signal from the wideband controller.

With that said, feedback on some other forums seems to indicate the wideband may be a little more slow-to-switch than a true narrow-band. So you may get some issues with how the self-learning function of the ECU interprets the results of that mildly-delayed signal. There's also warmup-time on a wideband (also on a narrow-band) and the potential for it to go out-of-calibration, so in general the recommendation is to run a regular narrow-band to the stock ECU. A stock sensor and a bung are pretty cheap. And if you're getting a tune, both banks can be run off of a single O2 (if you're so-inclined).

 

[Mustangless]

I did this years ago with a lc2 and tweecer. Can't remember how but it is possible. I'm thinking it was something I did on the tune. Single wideband placed in downpipe after turbo.

 

[Noobz347]

Years ago I built a 4cyl turbo mustang using a computer and motor from an 87 turbocoupe.

Not without help. That ECU only recognizes whether the narrowband sensor is operating within range.

I did this years ago with a lc2 and tweecer. Can't remember how but it is possible. I'm thinking it was something I did on the tune. Single wideband placed in downpipe after turbo.

This is the right idea. I wonder if there is a more modern equivalent to the TwEECer these days? @a91what I know there are plenty of EEC replacement options these days, how about Piggy-back systems?

 

[a91what]

Not without help. That ECU only recognizes whether the narrowband sensor is operating within range.




This is the right idea. I wonder if there is a more modern equivalent to the TwEECer these days? @a91what I know there are plenty of EEC replacement options these days, how about Piggy-back systems?

We are still stuck with the same ones from years ago, Tweecer and Moates are the only two that come to mind for the DIYer

 

[jozsefsz]

I did this years ago with a lc2 and tweecer. Can't remember how but it is possible. I'm thinking it was something I did on the tune. Single wideband placed in downpipe after turbo.

You can set the number of HEGO's and the assignment of the sensor to each cylinder in the tune. The output will still need to be an analog, narrow-band-voltage signal so you're not technically driving the eec with a wideband. You're driving the eec with a single simulated-narrow-band output. Not trying to be pendantic, it's just not possible for the eec to accept a wideband signal.