AFR sensor placement

[gongshowm1000]

I bought a 2011 m8 with a cutler stage 2 kit on it. Sleds been running great at 9-10 lbs boost. I have a AEM AFR gauge on it for tuning, my sensor is located right next to the pipe sensor, all the other cutler kits I've seen have the sensor mounted in the exhaust pipe after the turbo. Everywere I've read guys are saying to run a AFR around 12.2. When I'm WOT I'm seeing 13.2-13.7 plugs look perfect and wash looks great, if I add more fuel and get my AFR into the 12's it starts to bog a bit so I turn the fuel back down again. Would I be getting a false reading with my sensor next to the pipe sensor? Trying to decide if I should move sensor to the exhaust pipe after the turbo. Thanks for any info

Gongshow

P.S I'm addicted to Boost

 

[BigAir]

I have always been told that on a turbo application the O2 sensor has to be mounted after the turbo. The AEM instructions say to mount it after the turbo. The pressure before the turbo is said to affect the readings.

 

[BIGTurboT]

Hey

Just a quick picture of where mine is located, it's not in the best place as far as removal and installation being up against the shoulder of the muffler...hard to get a wrench on that's all. As far as A/F number go, they seem to be pretty accurate when compared to EGT, plug color, and piston wash. In all honesty I have never seen, nor heard of the o2 sensor being mounted in the expansion chamber. I would definetly look into moving it down to the muffler. Ill get a better picture up today.

 

[Snopro_69]

I've seen it in the pipe once but it will def give you false readings. I'd move er right where his pic shows

 

[BigAir]

Some companies recommend in the expansion chamber for N/A applications. I know SLP does.

 

[BIGTurboT]

Here are the pics, I dont believe the bung came welded in from Cutler and was done by the fellow who did my install. If I was to put the bung in myself, I would've placed it about 1/4" closer to the turbo so it would be easier to get a wrench on it. However, I'am planning on replacing that muffler with an different system of my own design... but that's a different story.

 

[gongshowm1000]

Sensor

Thanks for the replies guys, I'll be moving it to the muffler. Guess I'll be bugging the machinist at work to make me a new bung.

Thanks Gongshow

 

[Aerocharger_Brad]

Thanks for the replies guys, I'll be moving it to the muffler. Guess I'll be bugging the machinist at work to make me a new bung.

Thanks Gongshow

After the turbo is the correct location for many reasons....BUT if you are sure the sled is running correctly you can leave it where it is. Just remember the reading will be offset due to back pressure. After all the reading is just to help you know everything is still good. If you feel something and the reading goes to 11.5 or 15.2 you will know something bad has happened.

 

[BigAir]

Any muffler shop should have the bung.

 

[gongshowm1000]

Sensor placement

Thanks for the info guys, now does the sensor have to be mounted pointed vertical? Or can I weld the bung on the side horizontal? It would be a lot easier to weld it on horizontally, more room to work with

Thanks gongshow

 

[BigAir]

They suggest mounting it at least partially vertical so oil and moisture don't collect in the sensor. Ken with Push mounts his exactly horizontal, but on the inside radius of a bend figuring the oil will be pushed to the outside of the bend.