Drivetrain MTX-L yellow wire to replace stock o2 sensor
#1
#3
AFR gauge
I hope my post don't take you question off topic. I have been thinking of installing an AFR gauge to make sure the Mini does not run too lean on tracks. My only mod is 15% pulley and no tune. From all the threads I read I should be fine, but I don't know it that include a lot WOT on track.
I don't want to go thru all the trouble if I know my car would just be fine on track without bigger injectors. And yes, I read countless injector threads too. It seems there are very few has installed an AFR gauge in their mod'ed Mini. If I do I plan to weld a dedicated bung for the WB sensor. What cross my mind too is I would double check the header to be sure there is a good place for the new bung and the WB sensor, before buying a gauge.
For me, I would not want to try to share the WB as NB for the DME - to save welding on a new bung. I think scaling with a resistor network must have down sides.
I don't want to go thru all the trouble if I know my car would just be fine on track without bigger injectors. And yes, I read countless injector threads too. It seems there are very few has installed an AFR gauge in their mod'ed Mini. If I do I plan to weld a dedicated bung for the WB sensor. What cross my mind too is I would double check the header to be sure there is a good place for the new bung and the WB sensor, before buying a gauge.
For me, I would not want to try to share the WB as NB for the DME - to save welding on a new bung. I think scaling with a resistor network must have down sides.
#4
MTX analog out
OK. I looked into the MTX-L a bit more and now I see what you try to do. Have you find the Mini's DME's O2 sensor output characteristic?
Here is MTX-L yellow wire output voltage vs AFR.
I have read Bosch's O2 sensor literatures and they are typically clear as mud and give just a crappy graph not intend to be used quantitatively. Have you try asking Innovate support guys? They might be able to help.
Here is MTX-L yellow wire output voltage vs AFR.
I have read Bosch's O2 sensor literatures and they are typically clear as mud and give just a crappy graph not intend to be used quantitatively. Have you try asking Innovate support guys? They might be able to help.
#5
#6
I think we think the same of wanting to use the pre-cat O2 bung instead of welding in a dedicated new bung. The latter is likely easier said than done knowing the packaging challenges of the Mini. You want to weld in the bung between 9 and 2 o'**** and reality may make that impossible but I have not check.
So did you ever install the MTX-L? If not you, and soon me, just joint the long list of prolific posters on the mega injector threads that said it is a no-brainer to get a WB sensor instead of guesswork.
I am very apprehensive as I don't want to install the MTX-L with the NB emulation and only to screw up the pre-cat O2 signaling to the DME. I would prefer to leave the factor 02 sensor alone if I can help it, to avoid reading garbage-in, garbage-out that I screw up the DME F/A ratio.
#7
Trending Topics
#8
I have done this and been running fine for the past 5months, I tapped into the primary o2 signal wire and am using the MTX-L for narrowband simulation. You also need to simulate the stock o2 heater so that your ECU maintains adaptations correctly, this is the resistor I used (http://bit.ly/2uhElXq). You will also need to reprogram the voltage ranges for the MTX-L, I am running the range of 0.05v - 0.95v and left the factory AFR data.
I am also running the Bytetronik FA53 so my car is tuned and setup properly for all of these changes.
*also make sure you mount the resistor somewhere you won't light the car on fire, it will get hot and melt plastic.*
I am also running the Bytetronik FA53 so my car is tuned and setup properly for all of these changes.
*also make sure you mount the resistor somewhere you won't light the car on fire, it will get hot and melt plastic.*
#9
Thanks for all that shared your experience. Only when my stock header failed this past Friday that I made a point to see the challenges of fitting an additional bung for the WB gauge. It doesn't look easy - as anything on our little car.
While I like the idea of using the MTX-L analog output to emulate the narrow band pre-cat O2 sensor I have my reservation. That is how to ensure the emulation is close enough to the factory sensor characteristic (i.e. Lambda vs voltage). It would defeat the purpose if by installing the MTX-L only to bastardize the DME's fuel trim feedback loop.
My thought is may be the factory O2 sensor tolerances are very sloppy so you have to be grossly way off to screw something up. I would rather err on the side of caution in the absence of compelling evidence.
I welcome anyone who would share their experience and knowledge.
While I like the idea of using the MTX-L analog output to emulate the narrow band pre-cat O2 sensor I have my reservation. That is how to ensure the emulation is close enough to the factory sensor characteristic (i.e. Lambda vs voltage). It would defeat the purpose if by installing the MTX-L only to bastardize the DME's fuel trim feedback loop.
My thought is may be the factory O2 sensor tolerances are very sloppy so you have to be grossly way off to screw something up. I would rather err on the side of caution in the absence of compelling evidence.
I welcome anyone who would share their experience and knowledge.
#10
#11
My endeavour to the trouble of installing a wideband gauge is to see it for myself the A/F ratio at high WOT duty cycle on track, of the bone stock 330cc injectors, with bone stock ECU and 15% SC pulley. I have done copious search and reading dating back to the early days of R53 to no avail. There are many opinions from the prolific injector size posters but non that I can tell from putting their cars on tracks.
I acquired a set of JCW 380cc but I would like to know the change with each step of modifications that I do to the Mini. I will share what I find to all to see.
I actually plan not to install the gauge. It is one of those things that you only need to know the data once, and after that the gauge is just another nuisance, as well as the challenge to find a place to house it.
I acquired a set of JCW 380cc but I would like to know the change with each step of modifications that I do to the Mini. I will share what I find to all to see.
I actually plan not to install the gauge. It is one of those things that you only need to know the data once, and after that the gauge is just another nuisance, as well as the challenge to find a place to house it.
Last edited by pnwR53S; 10-03-2017 at 10:42 AM. Reason: added last paragraph
#12
#13
#14
expired o2 sensor
Thanks to Zsm, this expired O2 sensor arrives from San Francisco. I will reuse the pigtail harness and connector so no need to butcher up the Mini's upstream O2 harness.
astroblack53 sent me the link for the power resistor that I need to buy to fake the heater in the O2 sensor. I just need to open the wallet for it and the MTX-L Plus gauge. The biggest challenge for this project is to find a home for the gauge.
astroblack53 sent me the link for the power resistor that I need to buy to fake the heater in the O2 sensor. I just need to open the wallet for it and the MTX-L Plus gauge. The biggest challenge for this project is to find a home for the gauge.
Last edited by pnwR53S; 10-15-2017 at 05:43 AM. Reason: added second photo
#15
I have done this and been running fine for the past 5months, I tapped into the primary o2 signal wire and am using the MTX-L for narrowband simulation. You also need to simulate the stock o2 heater so that your ECU maintains adaptations correctly, this is the resistor I used (http://bit.ly/2uhElXq). You will also need to reprogram the voltage ranges for the MTX-L, I am running the range of 0.05v - 0.95v and left the factory AFR data.
I am also running the Bytetronik FA53 so my car is tuned and setup properly for all of these changes.
*also make sure you mount the resistor somewhere you won't light the car on fire, it will get hot and melt plastic.*
I am also running the Bytetronik FA53 so my car is tuned and setup properly for all of these changes.
*also make sure you mount the resistor somewhere you won't light the car on fire, it will get hot and melt plastic.*
I know that the O2 sensor heater is a closed loop operation (per what I infer from reading Bentley) so I would expect even if you fake the heater with a resistor the ECU may be unhappy because the narrow band emulation will not have the effect when the ECU turns on and off the heater.
Contrarily I suspect that the ECU may not know if the heater is not there, unless the engineer wanted the ECU to know if should the heating element goes kaputt. I am just trying to think through the issues.
Ideally, the best implementation is just to add another bung for the MTX-L gauge and keep the stock upstream O2. With the stock header it is close to impossible unless you are willing to risk putting the wideband sensor at a compromised orientation - potentially risking killing it frequently from condensation of water and whatever combustion byproducts.
#16
#17
My preference to keep the stock upstream narrow band is MTX-L's narrow band emulation will not have the causality of the ECU turning on and off the heater. It should, however, have a good emulation when the ECU thinks that the O2 sensor is hot enough. What still trouble me is how often the ECU turns on the heater. A lot to think about. It would be nice if it is not so difficult to add another bung at the angular range per the O2 sensor installation instruction.
#18
#19
ECU does check that there is resistance in the heater circuit. If it doesn't see resistance it'll throw a fault code because it thinks the heater circuit is broken. It's an emissions thing; heating up the sensor gets it to closed loop operation faster. Sensor heating is active for a short period every time ignition is turned on.
I've heard ppl do exactly that to avoid adding a resistor. It should work just fine.