Wideband in stock location poll

[turbowop]

Quoting JNR:
Lol, if you think these cars aren't cheap, better never get into anything newer or cars that're actually worth anything.



Cheap is relative, but considering the prices for other parts even on these cars, $50 is nothing.

 

[5OF2k]

Quoting turbowop:
According to this Bosch PDF , the operating temp is 930C and max temp is 1030C. If you're seeing those temps in your o2 housing, I think you have bigger problems.



Exactly. If your EGT's are higher than the above, you have some other issues. I've seen them last for YEARS in the factory location, on a healthy running car with a CLEAN tune. Mine isnt in the factory location at the moment, but when the T67 goes on, it will be in the DP elbow right off of the turbine housing, and it'll be just fine, because the car will remain healthy and properly tuned.

my .02...

-Jake

 

[toybreaker]

Some good posts in here! /ubbthreads/images/graemlins/smile.gif

... some quick philosabull (I'm late for work /ubbthreads/images/graemlins/wink.gif )...


I've often wondered if one of the things that kills an o2 in a turbo car is the radical hot/cold temperature delta it will "see" as the loading/conditions inside the motor.

When a car is driven hard for an extended period, the exhaust gas temperature will go from ~1500 ish on boost to effectively ~nothing~ on trailing throttle (the ecu shuts down the injectors)

The exhaust manifold/turbo hot side will come up to an elevated operating temperature after a few moments and stabilize.

... There's a lot of thermal mass there

But the sensing element of the o2 is just a little zirconia crystal, so it has jack and sh*t for thermal mass.


Things like to change their dimensions relative to temperature, so it's important to note that the bigger the delta, the bigger the dimensional fluctuations.

... 1500+ to stone cold, in the blink of an eye ... that's one HELL of a lot of delta! ...

and

The more thermal mass you have, the slower the change in dimension


So, here we have a stainless (maybe, sh*t dunno /ubbthreads/images/graemlins/dunno.gif /ubbthreads/images/graemlins/rofl.gif ) steel casing that contains the sense element bolted into a cast iron housing, and that casing holds a delicate little crystal.

The mani will be slow to change shape, the casing a little less so, but the wafer will change shape almost instantly when you drop the throttle and the exhaust stream goes stone cold.

The zirconia element can't like that much. /ubbthreads/images/graemlins/smile.gif



One would think that some distance would mitigate things,

... at least a little ...

as the more thermal mass between you and quick transients, the more the effect would be dampened. That two foot of hot pipe would throw at least "some" heat back into the gas stream, keeping things from swinging so quickly from one extreme to another.



... dunno, just a "theory" /ubbthreads/images/graemlins/smile.gif




edit

Even after all that philosabull, I would still run it in the factory position.

$50 bux ain;t sh*t in the grand scheme of things /ubbthreads/images/graemlins/wink.gif

 

[JNR]

I would think also what may play a role in the above would be whether the tubing was insulated and just how much...I mean, if you have 1200 F flowing thru there and even if it went down to a much lower number, the heat would still be retained to a certain degree (no pun, lol). But, screw theoretical and I'm sure in the real world, putting the O2 sensor down a few inches is not going to make enough difference to spend any time worrying aboout.

 

[James]

Good points toybreaker... But why do they do it from the factory? How is it that the factory o2 can hold up to the head for however thousands of miles... But "performance Intended" sensor cant deal.

 

[JNR]

Well, a wideband O2 has a greater range of 'reporting' to the ECU on more your actual A/F ratio, where the narrow band tells it if it's running lean or rich...Basically the WB is more 'sensitive' than a NB and I would think that *could* play a role in its accuracy based on where it's located, although we are talking so close together relatively speaking (both pre-cat and withing inches of one another), so I highly doubt it's going to make a difference. I'd say the oem location is more for packaging than anything else.

 

[turbowop]

So last night I installed a PLX wideband setup in 503 and put the Bosch sensor in the stock location. I picked up the PLX from CutlassJim for $80 and nabbed the Bosch sensor from Autozone for $50. Super cheap for a good wideband setup. /ubbthreads/images/graemlins/smile.gif I have it simulating narrowband and am logging it through ECMlink. Works great so far. We'll see how long it lasts... /ubbthreads/images/graemlins/grin.gif

 

[James]

I have my sensor for sale for like $30, unknown miles but I works. If you want an extra one on hand for cheap. Just the sensor and pigtail for plx250/300

 

Stock location. I don't have welding skills yet and always get raped every time I go see a welder. I'd bet a new O2 would be cheaper and less time consuming for me than taking it up the ass having someone weld a bung for me.