Swap Wide Band into collector and move ECU o2 down stream?

[PbFut]

I am prepping to install a wide band bung and have a question. The current ECU o2 bung is in the collector of the header. The only location I can realistically fit a 2nd bung is about 10 inches down steam. The bung in the collector seems so close to the primaries, I question how well it is reading all 4 pulses. I believe it is advisable to have the wide band as close to engine as possible. Given the above info, should I:
1) place the wide band in the collector, moving the current o2 sensor to the new bung and not worry about how close to the primary cluster it is. or
2) Place the wide band sensor in the new bung slightly down stream given the concern over the close proximity to the primary cluster in the collector?
Thanks for the input. I am pretty new to this.

[village_idiot]

Put the wideband in the further down bung so that both narrow bands can remain equal lengths from the engine. You will skew your fuel trims by moving only 1 side further downstream.

[kingtal0n]

Keep the wideband away from the engine. High exhaust gas temperature will wreck the wideband and skew the readings. I am pretty sure there is some note about this in the instruction manual. I know it varies from sensor to sensor and there is some lee-way when it comes to naturally aspirated engines where the EGT doesn't go very high.... but I digress. Look at the dynometer wideband sensor working from the rear of the car. Focus on wideband sensors people use in their post-turbine downpipes and note that the instructions probably say to install the wideband at least 3-4 feet away from the turbine. In some manuals.

Also I recommend learning to tune in open loop, and delete the narrowband sensors all together. 14.7:1 is neither ideal nor optimal. Keep the engine 14.8 to 15.4:1 air fuel ratio for the superior economy and cleanest spark plugs for idle and cruise.

24 years and hundreds of cars tuned and I never used a narrowband sensor except on my very first engine back in 1998ish when first learning to tune standalone computers. And that was before widebands became widely available for public use (affordable for the hobby)

[PbFut]

Thank you for the input. It’s settled, WB will go in the down stream bung.
I got to share. This is on a stroked and cammed LS2 swapped into a BMW MCoupe race car. NASA TT1. I have run the car swapped for more than 10 years and performed all work except tuning myself. Recently retired, I thought I would learn this fascinating field. So far it’s been more frustrating than fun, but I tend to overthink problems and then chase my tail. I am looking forward to my first write command but that is obvious to me, a ways down the road. I am having a challenge with the interface not able to standalone log a e40 ecu. (very hit and miss on channels selected) Might have to find a used tablet and mount in the car to correctly log. I can’t drive the car on the street so standalone logging was very appealing. I did not realize it was still so buggy I’ll keep at. Thanks for the input. I’ll be back with more basic questions, I am sure.

[kingtal0n]

I've tuned practically every stand-alone. They all work similarly.

Although stand-alones are simpler to utilize, they are also simpler in effect. In other words, we seem to have far more adjustability with the HPtuners solution on an OEM ecu than any stand-alone. Whether this is a pro or con is up to the user. For example I Love torque management and all the niche settings OEM ecu provides. I would be lost without some particular features that modern stand-alones do not offer. So for me the HPTuners solution is ideal in a daily driver application with regular tires at high power.

Good luck and we have a LOT of very helpful people here in these forums, which in and of itself is also a very big help above and beyond.

[PbFut]

When referring to stand alone I was referring to the standalone data log feature in the MPVI2 interface. It is very buggy attached to my e40 ecu. I can log just fine using a laptop and BT or USB connection, but if I load the channel list to the interface and log in standalone mode, most of the channels are not showing in the resulting log file. Given I can only log on the race track, the standalone logging feature would really be beneficial if it worked. We are OT but it my thread