LMR (Late Model Racecraft) Wideband o2 Sensor Location?

[Cantalope Kid]

I see a pipe welded to a jackstand with an o2 sensor portruding out the side which is inserted into the tailpipe of vehicle.


Anyone else seen or used o2 sensor in pipe sticking out rear exhaust location?


I always thought it necessary to remove (1) front o2 sensor

OR

Install seperate dedicated o2 bung before catyltic converter for dyno testing


Photo:




NOTE: MY QUESTION IS FOR EDUCATIONAL PURPOSES!

In my opinion LMR is the king when it comes to LSx tuning.

Photo taken from the video here:

http://ls1tech.com/forums/texas-memb...racecraft.html

[WS6FirebirdTA00]

I don't like it at the tail pipe, you get some lag in there and at low exhaust flows it does not read well. I would never tune off a tail pipe probe and I normally see a good spread between it and one inserted in the exhaust stream closer to the engine. Most people do it this way because it is easier.

[DSteck]

I would never tune off a tail pipe probe

+1

[Frost]

You will see the tail pipe unit in my photos and videos as well... though most of the time the unit used in the front bung does not make it into the pics or vids. I figure the dyno has the sensor and input, may as well use it too. It nearly always reads more lean at the back compared to measuring from a front bung.

[SSUte01]

You will see the tail pipe unit in my photos and videos as well... though most of the time the unit used in the front bung does not make it into the pics or vids. I figure the dyno has the sensor and input, may as well use it too. It nearly always reads more lean at the back compared to measuring from a front bung.

Exactly, it is fairly common practice. I have/will use a tailpipe bung as an added input or perhaps as a gross error check never to tune from, always tune pre-cat.

I would assume in that photo it is being used as a dyno input and then probably plotted on the dyno chart. Sometimes it isn't convenient or necessary to measure AFR pre-cat simply for a dyno run, but always necessary for tuning purposes in my opinion.

[LSxpwrdZ]

We do the same thing. I use the dyno wideband in the tailpipe and my NGK wideband in the collector or somewhere close, usually in place of an existing o2 sensor. It's impossible to tune low airflow regions with a tailpipe sniffer. Once I go WOT on the dyno I usually see a bit of lag between what's happening on my laptop and the dyno and the setups with sealed up exhaust and no cats I usually don't see any difference in readings once the delay is taken into consideration. But ultimately it's there for a sanity check.

[Tunning @ LMR]

We use the tailpipe for quick pulls to display on dyno file, I have a precat fast wide band that gets connected to laptop and interfaced into hptuners for tuning.