Motec M8 Wideband Lambda sensor selection

[davrianman]

Hi all,

I have an old Motec M8 which has wideband lambda, data logging and traction control activated. I am running the ECU on a 434 ci Dart Block Chevy V8 with a Kinsler injection system. The engine was mapped open loop without lambda enabled, but I now want to install into the completed exhaust system and run the engine in closed loop control.

From looking at forums and the M8 instruction manuals, is it correct that the unit is designed to run on wideband sensors only, or can normal narrowband sensors be fitted?

On another thread on this forum, it was stated that only a Bosch LM11 0258 104 002 sensor (now updated to LM11 0258 104 005 I believe?) would work on an M8. I think that this is a 4 wire wideband sensor, but some web sites do not state that it is wideband.

Can anyone please help me clarify what I should use with this ECU please as I'm not 100% convinced I have the correct sensor part number...

Many Thanks,
Martin

[AdamW]

You have many choices - since you have the lambda upgrade you can use either of those LSM11 part numbers connected directly to the M8. You could then closed loop control the lambda to whatever values you have set in the lambda table.
Another option you can connect standard narrowband sensors and still have closed loop control but in this case you can only control to Lambda 1.00 (you cant use lambda table).
Yet another option is to connect a standalone wideband controller(s) that use a more modern NTK or Bosch LSU sensor.

You can get the LSM11 for about USD$170 from oxygensensor.net, so thats probably your easiest option.

[Holmz]

You have many choices...
...
...but in this case you can only control to Lambda 1.00 (you cant use lambda table).
...
You can get the LSM11 for about USD$170 from oxygensensor.net, so thats probably your easiest option.

From the spec of the engine I would assume that some of the tuning may want to have a lambda <1.0.
Maybe the closed loop for partial throttle would be fine around lambda=1, so the narrow band would work.
But with a wideband you could at least log the lambda values when the throttle is more open, although maybe the narrowband provides some factoring that can be applied to cells away from lambda=1 (generally wideband territory)?.