O2 sensor placement on a Banana can Options

[aircooledtechguy]

So,. . . My header/muffler system on my shop-car works flawlessly and actually sounds really good too. However, I REALLY love the sound of the Porsche banana can muffs. So I'm thinking of converting my shop-car to a banana can muffler. Switching could also eliminate the occasional dragging of the muffler coming out of steep parking lots. The big issue though is where would I end up mounting the O2 bung so it will read correctly?? I'm thinking that with a muffler like this one below, over on the right side (closest end) near the end would be a good spot. . . What say you??

[Mike Bellis]

On the outlet, as hidden as possible, but must be mounted between 9 and 3 o'clock. Best is at 12. This will get mix of all the exhaust to sample and keep water and condensation from damaging the sensor. BTW, use a wide band...

[Black22]

From the research I did before mounting mine, all experts said that O2 sensors should be inserted BEFORE the muffler between the above mentioned 9-3 o'clock.

If the inlet is a single pipe from all four cylinders, (can't tell from the pic and am not familiar with the Dansk models), it should be installed there. If the muffler is a dual inlet, I guess at the outlet of the muffler is your only option. I'm not sure what that will do to your readings. (IMG:style_emoticons/default/confused24.gif)

[markyb]

I have submitted a request to PLX regarding the sensor placement as I have the same muffler as you and would like to make sure that the readings are correct.. I would rather have correct readings for one exhaust pipe before the muffler if I have to, rather than risk improper readings from placing the bung on the exhaust. Stay tuned for their reply...your pic of the exhaust should be of great help to them in giving me an answer, I was unsure of the chamber layout until I saw your info.

[Mike Bellis]

Theoretically speaking, The O2 optimum location is 12" from the exhaust port. This is especially important if you are using a non heated sensor. If your exhaust merges into 1 inlet to the muffler, place it there. If you have dual inlets to the muffler, place it on the outlet as I described above. If you use either a wide band (best) or a heated sensor, the outlet is fine. If you run a non heated sensor, it may tank up to 20-30 minutes run time to get an accurate reading. The exhaust has to heat up the sensor.

I'm not an expert in that muffler but I have installed plenty of 02 sensors on custom EFI systems. You need to capture all of the cylinders with your sensor or your not going to get good readings. You could have one cylinder go lean and never know it.

If you use a narrow band sensor, the reading at Stioch will bounce back and forth from rich to lean. This is why a wide band is best. You will get a true reading above and below Stioch with a wide band.

[aircooledtechguy]

I've already got a wide-band sensor (LC-1) that is mounted @ 12 o'clock immediately after the collector and it works great. I don't see it possible to get one mounted on the outlet though since it's got to be around 12"-15" from ambient air or it begins to have bad readings too. This is the current set-up:

(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1350180264.1.jpg)

[markyb]

here's the reply from PLX, I'm going with their option....

We would recommend installing the O2 sensor before the muffler. It is correct that it will limit the readings to one cylinder, but that will be give the most accurate readings.



I'd rather have an accurate reading from one cylinder than a faulty reading from all four

[Black22]

here's the reply from PLX, I'm going with their option....

We would recommend installing the O2 sensor before the muffler. It is correct that it will limit the readings to one cylinder, but that will be give the most accurate readings.



I'd rather have an accurate reading from one cylinder than a faulty reading from all four

(IMG:style_emoticons/default/WTF.gif) (IMG:style_emoticons/default/sad.gif) (IMG:style_emoticons/default/sheeplove.gif)

[Black22]

If its dual inlet, (2 cylinders per inlet) then weld 2 bungs and move the O2 sensor when tuning. Plug the unused one.

Nothing like getting good readings on one half of the engine while the other side is lean and melts! (IMG:style_emoticons/default/blink.gif)

[Mike Bellis]

If its dual inlet, (2 cylinders per inlet) then weld 2 bungs and move the O2 sensor when tuning. Plug the unused one.

Nothing like getting good readings on one half of the engine while the other side is lean and melts! (IMG:style_emoticons/default/blink.gif)

My Haltech is a dual WB O2 module. It can send an average or discrete signal to My innovate gauge. I can run 2 gauges to get both readings. I have seen other modules that accept 4 WB O2 sensors...

[Black22]

If its dual inlet, (2 cylinders per inlet) then weld 2 bungs and move the O2 sensor when tuning. Plug the unused one.

Nothing like getting good readings on one half of the engine while the other side is lean and melts! (IMG:style_emoticons/default/blink.gif)

My Haltech is a dual WB O2 module. It can send an average or discrete signal to My innovate gauge. I can run 2 gauges to get both readings. I have seen other modules that accept 4 WB O2 sensors...

Nice! (IMG:style_emoticons/default/piratenanner.gif)

[edwin]

I have the Haltech wideband controller and when I spoke to them about it they said at least 12" away from open air as worst case and ideally within 12" of a port

[markyb]

I've already got a wide-band sensor (LC-1) that is mounted @ 12 o'clock immediately after the collector and it works great. I don't see it possible to get one mounted on the outlet though since it's got to be around 12"-15" from ambient air or it begins to have bad readings too. This is the current set-up:

(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1350180264.1.jpg)

that's a nice setup, the collector looks like a perfect place for the sensor. Too bad with my Dansk I can't do the same. I suppose if I were to get real serious the PLX sensor module can accept up to 32 sensors, so one on each of my four exhaust pipes would be the ultimate. Since I'm running a stock L jet system rather than carbs, I'll pick a single tube about 12 inches from the exhaust port and see what I get. Here's the specs on the PLX sensor module:

The PLX Air Fuel Ratio Sensor Module accurately measures the wideband air fuel ratio (AFR) of any internal combustion engine. It comes with a Bosch LSU 4.2 wideband oxygen sensor. Up to 32 Sensor Modules can be daisy chained together from the PLX iMFD line for modular tuning and can be connected to any PLX Multi Gauge through the digital serial output port. This Sensor Module can also be used as a stand alone unit capable of interfacing with third party hardware where both the digital output and the analog output are available simultaneously. The SM-AFR works with gasoline, bio diesel, ethanol, methanol, E85, LPG, and CNG. Advanced soft start technology prolongs the O2 sensor life. The SM-AFR never needs to be calibrated and is accurate to 0.1 AFR with a tuned critically damped controller circuit for an ultra fast reaction time. The SM-AFR has a effective measurement range of 0.68 - 1.36 Lambda. It is also capable of reporting lean readings all the way up to free air with a DM-6 Multi Gauge.