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View Full Version : Best Place To Have Wideband Sensor?


JasonR
05-07-2004, 06:43 PM
Started this topic to hear everyones opinion on widebands and where you should bung the sensor after hearing this quote below? I put mine as close as possible to manifold. Have not noticed much of a difference compared to wideband on dyno when I tuned other then the fact when I dynoed I converted to fwd. I never tune on street, but have the wideband for an accurate reference.
Quote (Jet, may 7 2004)
Why did you reference a .94 O2 voltage if you have a wideband in the car?? That doesn't make any sense why you would even pay attention to a narrow band O2 sensor and not state what your WB02 was reading. Also, DSMlink should be approximating the AFR's from the fuel going in and the air going in. It shouldn't have anything to do with the stock O2 sensor. There should be a seperate logging input for that.

Also, a WB02 bunged that close has proven to be inaccurate in other applications. They should be 12" - 16" from the turbo.

I referenced .94 o2 voltage from dsm link under load. I always use dsm link. More importantly I always look at voltage for 02 because I have been using c16. Wideband gauge tells me a/f ratio (lien rich) not voltage, only meant for reference while driving. I stated what narrow band or what dsm link tells me because I assumed this person would know the difference. Looking at my last capture run under load, it indicates .94v fronto2, 6000rpm, a/f ratio 9.52, timing 17.9, no knockret. I did state earlier on dyno wideband avg. 12.0 a/f ratio wot. Definition of oxygen sensor is: Use with the feedback system to sense the presence of oxygen in the exhaust gas and signal the computer which can reference the voltage signal to an air/fuel ratio. That is answer to his question, but bunging the wideband to close has been proven to be inaccurate. Not in my case. What are other people doing or where do they bung the sensor for wideband? :3gears:

Goat Blower
05-07-2004, 10:56 PM
As close to the turbo as possible. You could temporarily swap in your wideband sensor for your O2 sensor if you want to do some WOT tuning. Or you can have another bung welded on somewhere depending on your O2 housing setup.

JET
05-08-2004, 02:14 AM
Your WB02 should not be your reference, that should be the main one you look at. .94 off the front O2 doesn't tell you anything because it is out of its normal operating range. It is made to sense a narrow band around 14.7:1 AFR. Hence the name narrow band O2. You wideband is made to sense from 9.0:1 to 20.0:1 usually. I don't even use my narrow band because it is worthless.

As for the inaccuracies, some people on the WB02 list (techedge) found that the swirling air coming out of a turbo could cause problems with the accuracy of the 02. You also do not want the 02 sensor to be above 1200 degrees, which it may get to near that point that close to the turbo. If yours is working, then that is fine. It is just not in the recommended location.

I also don't understand why you don't tune on the street at all. Where do you drive? Then that is where I would tune. I also don't understand the problem with getting AFR's from the WB02. You shouldn't be over 11.5:1 on pump gas.

JasonR
05-08-2004, 01:35 PM
Now your realizing what I am doing. I look at about 6 parameters of data with dsm link when I do capture. I watch narrowband front02 voltage right now because I have gone through one 02 sensor this spring. ECU uses front o2 as reference for a/f ratio. If it goes not good. In fact I am waiting for md998464 side connector so it is easy for me to check continuity of front o2. Not running pump gas. In fact my dumb ass tuned the car to only c16 on dyno. I ran out of time on dyno 3 weeks ago and plan to go back and turn up boost and re-tune asap. In about one more week AWD Dyno will be available in twin cities. I know we cannot advertise other shops, but everyone is going to know where it is soon. I need to tune to pump gas as well so I can drive to brainerd this summer. I don't want to drive at $9 a gallon for 2 hrs. C16 fuel coats up and poisons the o2. Difficult running on street with c16. I have tuned or made a few adjustments on street, but not enough to really matter. I really only drive car once a week. And I don't like driving with lab top up, I have touch pad labtop. I have to lay it on the rider seat doing capture when driving. I just want to enjoy the car. My connector for power transister keeps coming loose. I plan to drive today and make sure it stays on after I replaced last night. I think I should of put the wideband in better spot after listening. I am most definitly going to watch EGT under full boost and temp today. I want to see if goes past 12.5 or 13. I only recall it around 12.5, but friend tould me you have never paid allot of attention to it. Thanks for the comments, suggestions, etc. :3gears:

JET
05-09-2004, 12:28 PM
Do you have the wideband in all the time? Almost all of the widebands have a narrowband (0-1v) output now, so you don't even need the stock 02 in there. Your narrowband voltage is just a very rough guesstimate on the AFR's, because it is not calibrated for anything richer than 14.0:1. If you have the wideband, why not use it? It is like have a power saw, but you decided to use a hand saw just for the hell of it. Why not use the better one?

Pushit2.0
05-09-2004, 10:48 PM
I use the tech edge for tunning, its in the exact spot of the stock unit. It also gives the ecu the 0-1volt reading, I like it a lot.

~John