Wide-Band O2 sensor

[fast eddie]

What air/fuel ratio to shoot for with alky and were to mount the probe?
Changing from Trans Plus to Maf Pro
HELP! :biggrin:
Ed

 

[bruce]

What air/fuel ratio to shoot for with alky and were to mount the probe?
Changing from Trans Plus to Maf Pro
HELP! :biggrin:
Ed

Run the AFR that testing shows that your car likes. It can vary alot, from car to car.

I have my WB mounted down by where the cat was.

 

[fast eddie]

Run the AFR that testing shows that your car likes. It can vary alot, from car to car.

I have my WB mounted down by where the cat was.

Thanks Bruce

 

[Speedz06]

I would try to mount in a crossover or h-pipe so that I could get a better average mixture reading.In my car I mounted to an h-pipe between the header collectors so I wouldnt be reading only the left of right side.

 

[Razor]

I would try to mount in a crossover or h-pipe so that I could get a better average mixture reading.In my car I mounted to an h-pipe between the header collectors so I wouldnt be reading only the left of right side.

Buicks with single exhuasts dont have H pipes :wink:

My target has been 11.3.. for me.. WB has been on the DP 1 foot away from Turbo..

 

[Scott Atk]

I recently used 11.4 as a target. But since I shot molten aluminum out the tailpipe, I'm gonna shoot for 11.0.

 

[norbs]

You can;t conculde that as there are 7 second cars running at 12.0 a/f, you had other issues. You would have melted all 6 pistons...

 

[Speedz06]

OOPS sorry--shows what I know

 

[bruce]

In my car I mounted to an h-pipe between the header collectors so I wouldnt be reading only the left of right side.

That can be a relatively *low flow* area. Which can lead to really slow responses, and in some cases missing some transitional AFRs altogether.

If you want to read both banks, you really should have 2 WBs.

 

[FWD turbo]

Why are you guys mounting your WB in your downpipe after the turbo, as opposed to before the turbo, like in the y-pipe or stock O2 sensor location. What is the benefit?

 

[bruce]

Why are you guys mounting your WB in your downpipe after the turbo, as opposed to before the turbo, like in the y-pipe or stock O2 sensor location. What is the benefit?

The WB sensors are much more sensitive to particulate matter. At high EGTs even the least amount of oil contaimination will poison one. Then there is the matter of the WBs operating at 1,650dF (NTK type). As the EGTs approaches that temp, it can skew the reasings. The Bosch sensors are even worse, and need to be run below ~1,100 dF.

I've got 10,000's of miles on mine with it being by where the converter was, actually 2 of them, one NTK in the car, and a Bosch in the truck.

The stock O2 is a really basic unit, and not too easily influenced by EGT or back pressure. All it has to do is determine if the O2 is high or low. The WBs on the other hand have to be accurate thoughout their entire range.

 

[FWD turbo]

Thanks for the explanation Bruce. I am thinking about switching over to a MAF pro and WB this spring, so this conversation interests me. I figure if I start figuring things out now, it will be much easier come springtime.

 

[bruce]

Thanks for the explanation Bruce. I am thinking about switching over to a MAF pro and WB this spring, so this conversation interests me. I figure if I start figuring things out now, it will be much easier come springtime.

In the service, one of the motto's *we* had was, Prior Planning Prevents P!ss Poor Performance. Seems to still be true


I got to dink with one of the Beta versions of the MAF Pro in Bailey's car in BG, seemed like a slick unit.

 

[norbs]

The stock O2 is a really basic unit, and not too easily influenced by EGT

This statement is absolutely false! Temps have a huge effecton narrowband voltagesthat why you don't rely on them for tuning!

 

[bruce]

This statement is absolutely false! Temps have a huge effecton narrowband voltagesthat why you don't rely on them for tuning!

They should only be used for checking for stoich., EGTs don't effect their output that much at stoich..

Only the poorly informed use a WB for tuning.

Narrow bands are only designed to check for rich or lean of stoich..

Try reading the whole paragraph before getting too excited. When you start talking about several items, you have to use more then one sentence to explain the concept.

BTW, your chart perfectly matches what I said, once you read the whole paragraph.

 

[norbs]

Ahh, i was just speed reading i guess......will look at the whole story next time

 

[Speedz06]

Bruce--you seem to know your stuff and I'm a pretty well trained tech--are you saying that you shouldnt tune with a wideband?I just bought one because I thought that was the only way I could get a true AFR reading.

 

[bruce]

Bruce--you seem to know your stuff and I'm a pretty well trained tech--are you saying that you shouldnt tune with a wideband?I just bought one because I thought that was the only way I could get a true AFR reading.

YES, by all means use a WB!!.
The thread sorta took a twist with the mention of the shortcomings of the stock NB.

A WB will save you hours, but like everything else they aren't perfect. Use it in addition to checking your plugs, and EGTs (if you're monitoring them).

Personally, I have one mounted permanently in the GN, and then one, that I can easily transfer from one car to another. Once you get used to them, it's hard to imagine how ya got by without one.

 

[Speedz06]

Yeah, I like having a wb now.I liked being able to see the AFR change by changing from 50/50 to 100% alky.