[GTT 280]

Hi all,

Can anyone explain how a wideband O2 sensor can be fitted to a car and linked to a dash mounted data logger, when there is already an O2 sensor fitted that is linked directly to the ECU.

How can the calibrated sensor be used to i) provide an accurate a reliable figure on a dash data logger and ii) be used to provide data to the ECU?

would they remain seperate, or would the wideband replace the OEM sensor?

Is the sensr used to determine correct fuelling, and if a wideband sensor was used that was more acurate, would this provide more accurate A/F ratios?

Confused

Cheers,
K.

[GRSmotorsport]

Hi Karl,

I have fitted an Innovated AFR wide band gauge to my MSC. I rang Roland to ask where the best place was to have the additional CO sensor, he recommended to have it before the cat, and as close to 12 o'clock on the exhaust manifold, this stops condensation from ruining the sensor!!

I had to calibrate the sensor as per instructions, which wasn’t difficult. The only down side is I have to have my lap top in my car to record the AFR information, then watch it back when finished…

[GTT 280]

What is the benefit of having a wideband O2 sensor, and not just using the OEM o2 sensor as fitted?

My underlying requirement here is to be able to fit sensors to record the two most important variables when running an engine hard. Would one be the A/F mixture? or would it be Oil temp and knocking sensor? or ????

Any advice greatly received as i am heading into this blind really.

Cheers,
K.

[MINI-Morgan]

Are you really that worried? Planning some custom mapping maybe??

[GTT 280]

Quote: Originally Posted by MINI-Morgan (original)

Are you really that worried? Planning some custom mapping maybe??

If you are pelting round a race track for 200+ miles you need some indication of possible problems like reaching limits on temp and pressure etc.

It's more of an insurance than a necessity. It's also for personal interest.

Yes, custom mapping to follow soon, but not by myself

So... back on topic - what are the most 2 important sensors to get fitted???

Cheers,
K.

[Richard Crofts]

Have a word with LuckyDave as I believe he has a multitude of sensors on his car, and has fitted sensors and guages to a number of MINI2 folks vehicles

[GTT 280]

nice one, thanks for the info

Cheers,
K.

[GRSmotorsport]

Karl,

Personally I think you only need 2 gauges to look at AFR & oil pressure, these are the 2 most important bits of information you need while driving in my opinion, plus there’s only so much you can read when rushing around a track or private road! Admittedly it’s still nice to see what’s been happening after you’ve got out of the car.

I remember going around Castle Combe in my friend Cosworth everything was fine until the AFR‘s went very high all of a sudden for no apparent reason, car still seemed fine and drove ok, but my friend decided to slow down and went straight into the paddock, lifted the bonnet where I noticed the vacuum pipe from the fuel pressure regulator to the inlet manifold had come off causing the weak mixture!!!!, once refitted everything was fine. If my mate hadn’t had that gauge we would have never known the mixture had gone weak and probably blown the engine up within minutes…..

[THEWORKSMINI]

The reason for using a stand alone wideband o2 sensor is because they have a much larger measuring range.

A jump cell (narrow band) oxygen sensors measuring range is between 0 and 0.8v switching between these values once every 1.5 seconds at a stable engine speed and load.

In simple terms this sensor can tell you the car is lean or rich but not by how much!

The wideband sensor has a much larger range of measurment it can more accuratly tell how rich or lean the engine is.

The wideband sensor has 4 wires, 2.5v Ground wire, 0.5 signal wire, 2 wires with an alternating +/- DC current called the pump cell.

You cannot fit an AFR meter after the cat it would simply read lean all the time, as the o2 value after the cat should be more than before.

Hope that helps

Lee

[GTT 280]

excellent information - thanks guys !!!

I think i also learnt today that the wideband can be wired in to the ECU to give a more accurate AFR response - is that correct?

Cheers,
K.

[MINI-Morgan]

Dont the wideband sensors have a limited life span too?

[Richard Crofts]

Oh and the stock sensors measure rate is quite slow as its linked to the OBD I think, meaning you only get a measure every Xth of a second where an aftermarket unit would measure more times in a second??? May be wrong on that though

[MINI-Morgan]

Quote: Originally Posted by Richard Crofts (original)

Oh and the stock sensors measure rate is quite slow as its linked to the OBD I think, meaning you only get a measure every Xth of a second where an aftermarket unit would measure more times in a second??? May be wrong on that though

True but its more the OBD interface is slow than the sensor. The ECU reads the sensor constantly.

Certainly a standalone wideband sensor + AFR computer will be the best option.

Actually Karl why not just buy a fuel computer that monitors AFR and you can modifiy your fueling to suit your mods too. Apexi Neo always looked good from memory....

[Lucky Dave]

Its not just as simple as swapping the cars sensor for a wide band sensor. the ecu has a heating circuit and will look for a connected sensor.

I have all the standard sensors and two additional w/b sensors feeding gauges and logger.

Additonally I would fit some exhaust temp sensors if your going to go all the way.

depending on your boost you may want a good boost gauge AND fuel pressure to assure the fuel fressure does not max out while the boost is still climbing.

I dont tend to use my oil pressure gauge that much as the warning light will tell you if the pressure has stopped big time! but it wont tell you gradual changes as your oil gets older like a gauge will.

Its possible to have everything monitored and still keep the dash looking un cluttered.

[MINIdriver85]

Quote: Originally Posted by GRSmotorsport (original)

Hi Karl,

I have fitted an Innovated AFR wide band gauge to my MSC. I rang Roland to ask where the best place was to have the additional CO sensor, he recommended to have it before the cat, and as close to 12 o'clock on the exhaust manifold, this stops condensation from ruining the sensor!!

I had to calibrate the sensor as per instructions, which wasn’t difficult. The only down side is I have to have my lap top in my car to record the AFR information, then watch it back when finished…

You could always hook that up with a datalogger and then download the data. Even ebtter if the datalogger has a SD card, you don't even need to brignt he laptop in the car to download the data, you simply move the SD card. Which is why I'll probably get the DashDyno and hook it up with both a wideband controller (still undecided between Innovate, PLX and Zeitronix) and an EGT probe. So I have those two info together with all the OBD sensors too, and can record up to 16 parameters at the same time...

EDIT: Does the Apexi AFC NEO monitor AFR? I thought you just used it to change it, but still needed a wideband for monitoring it...

[roland2003]

..Just changes it, it cant monitor it. They are not without problems though. If your adjustment corrupts the voltage signal by more than x amount you will get EML situation. ...We have in stock.

[MINIdriver85]

Thanks Roland, just collecting info on it as I plan to get it after/if I fit head and cams. Considering I have a One and I have to swap the tranny before heavily modding the engine, it will take some time

By the way, do you have any personal experience with the three widebands I mentioned? Could you give me advice on which one is better (if one is better)?

[bahambart]

here's a pic for you guys.


The gauge is from PLX devices. I had opted for this gauge because when researching, they referenced that you could use the supplied O2 sensor to perform both functions - 1) the A/F gauge and 2) the ECU. I found this appealing since I don't weld and figured I could handle the cable splicing. HOWEVER, when I got the gauge, inside was a bag of resistors and the rest was left for me to figure out. I contacted a Mini vendor who sells the gauge for assistance and they encouraged me to just add a bung and leave the ECU alone. So the primary decision on gauge choice was wrong however the gauge works great and is self calibrating.

I just wanted to share that the clean and simple approach is to add a bung, yes before the cat. In my case I have the OBX header and the bung was added with it on the car -- no problems. Once the bung was adddwiring was simple.

[MINI-Morgan]

So you have no pre CAT or post CAT O2 sensors connected to the ECU? Doesnt that cause problems with running closed loop fueling??

[MarkW]

lot of cars run closed loop with only 1 sensor