Best spot to mount wideband o2 sensor

[Bobby Fazio]

Using the accel dfi system in the stocker 5.0, where should I mount the o2 sensor? Certain parts of the collector better than others?

[Signman]

Have been told the optimal location is within 20 inches of the valve.
If you want it in the collector it should be long or add an extension to reduce the effect of fresh air pulled in.
When achieving the optimal air/ fuel ratio that indicated in the primary tube will be different from that in the collector.
One thing to put some thought into fuel distribution is pretty even with EFI so measuring one cylinder will be fine. There are exceptions, nothing is perfect, having an O2 in each primary would be optimal.
The thing to do is get together with a good tuner with a chassis dyno. Getting in the ballpark right away is important.

[MOTORSPORTS Innovations]

2xwhat Frank said. Put it into a primary. When you are welding the bungs in, put in 2 or more on each side and then you can move it around if you like.

The 600 cubic inch bracket motor guys can get away with it in the collector 75% of the time. 302 stocker - no way.

[art leong]

I have one of mine in the collector only 9 inches from the end. It is useless till around 4,000 then it works fine.
I have another in the primary tube (number 4). They don't read the same. I'm going to recalibrate them both. But I want to do it at the track. So I can see if there are any changes in the numbers and what seems to be the optimum number for me.
Right now the car runs quickest at 13.5 to 1 AFR. I don't want to recalibate them in the garage and have that number change. And be lost when trying to tune at the track.

[Bobby Fazio]

Accel only gives you 1 so I would think it has to be in collector?

[MOTORSPORTS Innovations]

Originally Posted by Bobby Fazio

Accel only gives you 1 so I would think it has to be in collector?

Dean Oilver, some of the Louisiana crew, tons of my bracket customers have the same issues Art talks about until they put the bung in a primary. Racepak, FAST, Innovate Motorsports all say in a primary tube. In the collector works fine for cars with full exhaust.

[Tom Goldman]

I've welded bungs at 16"+- on all my primarys and one on each collector close to the merge.
Tuning by the primary readings is the best place to start. ....I've taken readings in all 8 primarys, using just a single channel O2 ,and now just moniter one.
After you have a baseline established ,you could move the sensor to the collector and moniter the readings, but the primary will tell you much more about lower RPM than the collector.