RomRaider

In my previously posted diagram, i simply cut the brown wires for o2 heating grounds from the circuit.

Thanks for the update. So you basically left ECU Pins 61 and 79 disconnected from your WBO2 and MAP sensors?

Just for the sake of completeness, would you mind posting another revision of your wiring diagram that illustrates this? This way we can use it as a reference for posterity.

updated wiring to reflect what i have implemented

ba114, nice diagrams and information!!

I understand why you used the DME sensor ground for the MAP sensor since you are using the 5V reference voltage from the DME for operation of the MAP. However, I'm a bit confused/curious as to why you used the DME sensor ground for the wideband (assuming pins 71 and 72 are both sensor grounds -- I didn't check), since the electronics of the wideband controller are completely separate from the DME other than the output signal it's generating.

For what it's worth, my wideband output to my rear O2 signal wire seems to be working perfectly (although I haven't logged lately) and the only wiring I have between the wideband and the DME is the 0-5V signal output from the wideband connected to one of the rear O2 signal inputs.

As an aside, I will be slamming a turbo onto this car starting in about a week, and it would be really cool to be able to log MAP for the sake of tuning. What MAP sensor did you end up using for this?

I got a cheap $12 3bar chcinese GM knockoff. I think it's more than fine for logging.

Unfortunately logging wideband through the o2s is significantly slower than stand alone.

I used the DME sensor ground for the wideband purely because i want to keep the engine harness/connections all as one piece so it can be removed from the body easily (engine swap in e30 may need to be removed semi-regularly).

It works but its possibly not the best as far as grounds could go. I'm noticing some possible interference which affects the readings through the dme i.e. the recorded voltage of the rear o2 in rr logger doesnt match the voltage of the innovate WBO2 plugin. unsure if this is why, probably not. Maybe its a difference is polling speeds.

The map sensor im using is just a cheap GM knockoff from ebay.
The formula for psi is (V*8.94)-AbsolutePressure
Using torque pro i have this as a gauge with a custom PID that detracts the current absolute pressure logged from my phone based on location.

Thanks busterhax! Assuming that is from eBay, are there any part numbers to look for or anything beyond what you mentioned? Also, I think we determined before that these MAP sensors are linear, so the voltage to MAP relationship should be easily google-able, correct?

Interestingly about the latency or lag time for logging, no doubt it's slow as you say. I've found that I can get useful information though, usually by just keeping in mind that the indicated AFR corresponds to the prior datapoint for everything else. I was able to dial in a pretty nice tune that way at the drag strip over the course of a couple of visits. I was concerned at first, but as I saw everything moving in the direction I wanted it to, my concerns were alleviated.

ba114, I see you posted while I was typing, thank you for that formula!

Do you prefer to log with Torque Pro rather than RR Logger? I've found RR Logger to work very well, and when played back with MegaLogViewer you can use formulas you input into MLV to have it read out actual AFR instead of voltage (or probably actual MAP I hope).

I find rr logger better for logging. I just use torque pro for live gauges

Cool, I'll give that a try today! I've never used it with this car.

I ordered one of these last night. I'm assuming this is what you guys were talking about?

http://www.ebay.com/itm/171124019819

That's the exact listing I purchased from. Haven't wired it in yet though.

Thanks!

I have that exact one on the way too. The first one I bought seems to have died now. It's no longer registering changes in pressure.

Yes, IIRC the ECU only polls the rear O2 sensors every 100ms. It's quite slow, I agree. Alec found there are several threads that respond to varying time delays. Some are 10ms versus 100ms etc. Hopefully in the future we could have it poll every 10ms (instead of 100ms).

Hence why any input from the rear O2 sensors (for the moment) should only be used as a reference.

New sensor tested working



Yep front o2s are 10ms, rear o2 are 100ms. From memory, with single channel o2 control bit, it was confirmed that if you keep a sensor plugged in, then the code will factor it in calculations correct? if we can identify a way to still use the spare primary o2 bank input for MAP or AFR type logic that would be beneficial.