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Wideband sensor for Air/Fuel Ration (AFR)

Posted: Mon Oct 07, 2013 2:32 am
by romus
If this is useful, here is how to connect up an Innovate LC-Wideband sensor and controller. I had this working before when tuning the Weber but because I crashed and left my last one on the road, I am redoing it.

This allows you to read the Air/Fuel mixture, which is useful for tuning your carb. If like me, you are not confident enough to work it out by ear, spark plug tests etc. Well, it is accurate so I think the tuning process will be faster and more accurate. You can get a readout on a data display on your dash so while riding at the points where the jets come in on your carb you can see exactly the effect and accurately re-jet – also for adjusting the idle. It can also show you the effect of seasonal and altitude changes, so you can make informed decisions on when and how important it may be to adjust the carb for those changes.

These are being sold on e-bay for US200 at the moment, but it looks as though they are being superseded by the LC-2 (http://www.innovatemotorsports.com/products/lc2.php). You just make sure there is a kit with a gauge or you add on a gauge to your order. I also ordered an extra bung and screw plug so I could swap my sensor between the front and rear exhausts to measure both cylinders.

Here is a picture of the pack I used.
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To install:
1. You will have to take off your exhaust pipes and get the bung/s welded in. I took mine to a motorbike engineer. I think it cost me $50. I got an extra bung (ordered 1 extra) put in so I could swap the sensor over to measure both cylinders. As per Innovate's suggestion I cut a piece from a copper pipe, drilled a hole and used that to displace heat when you screw in the sensor.

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2. At the other end there is the readout gauge. This could either be mounted on the dash where the clock goes or on that dash strip.

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3. Wiring
Follow the Innovate instructions to wire up the the gauge with the Wideband controller, the gauge and the bracket. I then enclosed the bundle of wires in some heat shrink (not shrinking it) and bound it up in electric tape. The Innovate supplied bracket that the wire bundle is attached to can now be bolted on to the horn attachment.

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This also requires a fuse for the power/red wire and, to attach it to the horn, wiring into the horn green wire.

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4. Connect up the Wideband sensor and controller. The wire from the sensor can be fed up to a point on the frame and likewise the Wideband controller can be fed from the horn attachment to the same point on the frame and the two connect up.

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4. Calibrate the sensor. In the picture above the small circle is around the small red flasher and the larger red circle is around the red push button. These are used to calibrate the sensor - which is done with the sensor out of the exhaust pipe. After doing that screw the sensor back into the exhaust.

6. Done :-) Now when you start the bike it takes a few seconds and you then get a readout on the gauge. Here the gauge is showing 13.2 at idle. 12.8 – 13.2 seems optimal across the jetting range with early 12s to late 13s being fine. The figure is the amount of air to one part of fuel – known as AFR:

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NOTE: There are also two wires from the Wideband controller that can plug into your PC and with the innovate software you can record a graph readout. I tried this with a laptop in my backpack, but really I don't think it is needed. Riding and checking the gauge readout in real time seems ample enough feedback for your carb jetting decisions.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Mon Oct 07, 2013 9:54 am
by Tamburinifan
Nice write up! :)
NOTE: There are also two wires from the Wideband controller that can plug into your PC and with the innovate software you can record a graph readout. I tried this with a laptop in my backpack, but really I don't think it is needed. Riding and checking the gauge readout in real time seems ample enough feedback for your carb jetting decisions.
You do need to log rides to see anything you could really use.
The readings when riding & reading will be blipping around.
http://www.youtube.com/watch?v=YvrLkr9UUS0
Do log, several long runs and preferably under load, driving uphill.
Then you'll see an average at different RPM & throttle that will give you
a hint how to jet/adjust.
Although the meter is thrilling :thumbup: , it is inaccurate. And dangerous, if hypnotized by it....

To get real useful data, you´ll need a Throttle Position Sensor, too.
Now your logging only shows AFR, not with various throttle positions, right?


I've used a LM-1, it's a helpful device.
2 links to roughly see advantages of logging:
http://myweb.tiscali.co.uk/tlweb/tr6/in ... thod4.html
http://www.fordmuscle.com/archives/2006 ... index2.php

What useful logging can bring:
http://www.innovatemotorsports.com/reso ... itions.jpg

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Mon Oct 07, 2013 10:39 am
by higgy
Microsquirt will do the same thing for less overall.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Wed Oct 09, 2013 11:01 am
by JWilliam
Awesome stuff Warwick and very well done too. I've always relied on the seat of my pants to judge the mixture but well know a dyno-shop truly gets the best result for fuel injection.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Wed Oct 09, 2013 1:18 pm
by higgy
Yes a TPS would help much Gert

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Thu Oct 10, 2013 12:34 am
by Mc tool
Is there any reason that the sensor cant be fitted to the exhaust after the collector , so as to get a combined reading from both pots at once ( to be honest Im thinking more of my 390cfm Holley carb on my rover v8 engine and its 4 -2-1 headers and the tuning there of ) , all things being equal ( like after you have sorted the cam timing :) ) any adjustments would be the same on both pots ( again the rover ..... with one carb for all 8 pots ) and ( in theory ) if you, for arguments sake , had the bike idling and the sensor in one tail pipe any adjustments to only one pot would still show up on the meter , all be it with reduced sensitivity
Just thinkin ahead :) :)

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Thu Oct 10, 2013 10:35 am
by higgy
Mctool, you can buy an adapter to stick it in the end of the tailpipe. The only real requirement is that it be in front of any convertor

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Thu Oct 10, 2013 2:56 pm
by paso750
usually it`s said that on a motorcycle the sensor should be fitted ca. 30cm from the cylinder head flange.
Is there any reason that the sensor cant be fitted to the exhaust after the collector , so as to get a combined reading from both pots at once ...
If the synchronization is right you only need to measure on one cylinder, that would be ideally the rear as that is more critical.

More and more cars now use two sensors. One in the collector and one after the catalytic converter. The first sensor is full in the exhaust fumes while the second one is in contact with the surrounding air. The surrounding air is used as reference to correctly measure the residual oxygen.

The sensor also needs a certain heat to work properly just like a catalytic converter so the more you move it away from the engine the more imprecise its output will be.

G.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Thu Oct 10, 2013 10:15 pm
by sergiomala
Interesting.......

do you think this one will be more useful?

http://www.ebay.it/itm/290985675170?ssP ... 1423.l2649

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Fri Oct 11, 2013 12:53 am
by higgy
usually it`s said that on a motorcycle the sensor should be fitted ca. 30cm from the cylinder head flange.
Different kind of sensor, G.... Wide band can be mounted anywhere along the exhaust as long as there is no cat


LM-2 is the defacto standard these days for wide band data collection

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Fri Oct 11, 2013 8:07 am
by paso750
higgy wrote:Different kind of sensor, G.... Wide band can be mounted anywhere along the exhaust as long as there is no cat
that makes me wonder as some datasheets for Bosch sensors state: ideal operating temperature for sensors 550-700°C and wideband sensors up to 800-900°C. You won`t get those temperatures everywhere in the exhaust.
But this is going a bit offtopic, sorry.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Fri Oct 11, 2013 10:47 am
by higgy
most wide bands have their own heat source, for that matter most o2 sensors these days are heated

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Fri Oct 11, 2013 11:02 am
by paso750
not quite right, the heat source is not to get them to ideal operating temperature but to boost their activation time. The sensors only start working when they reached min 250-350°C.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Fri Oct 11, 2013 11:50 am
by romus
Tamburinifan wrote:...You do need to log rides to see anything you could really use.
The readings when riding & reading will be blipping around.
http://www.youtube.com/watch?v=YvrLkr9UUS0
Do log, several long runs and preferably under load, driving uphill....it is inaccurate. And dangerous, if hypnotized by it....To get real useful data, you´ll need a Throttle Position Sensor, ...
Hmm, I think it's not fair to say the digital gauge is not accurate. It is exactly the same data - it's just displaying it on a gauge or as a data graph. That's the same thing. In the video link, that is the sort of up and down reading I would get on the motorway when the pull on the motor goes up and down, but if you ride up a hill e.g., in 3rd gear and the pull is consistent then the data readout is stable. Anyway, if you make multiple tests reading graphs or a gauge you will, I think get clear and right information for your jetting changes.

On the throttle sensor - I also think there is not an issue. You can learn soon enough by reading about the points where you carb jets come in in relation to revs and acceleration, e.g., very slight throttle being idle jet, etc - that info is available as tuning info and you can easily enough take it into account. AFR readout, any which way you look at it, is a huge help in tuning.

I do agree it can be mesmerizing and think referring to a gauge while riding needs multiple tests, so by glancing every now and again over multiple uphill tests you really get it right. I think, yes better on an out of town hill and better to take a gauge away, or unplug for normal driving. I think for me then I will not attach it this time where the clock goes.

Actually, yes sergiomala's link http://www.ebay.it/itm/290985675170?ssP ... 1423.l2649 seems a solution for anyone's preferences.

Re: Wideband sensor for Air/Fuel Ration (AFR)

Posted: Fri Oct 11, 2013 6:50 pm
by sergiomala
I'm truely tempted........ as long as my bike is not running smoothly, overall in low rpms range or starting after a red light.
But the Wideband a/f gauge is only one of the parts.
I need also the manual of the weber carb to know where to touch in order to obtain the best response to the gauge. I have never had my hands on a car carburator installed on a bike.
I apologize for my ignorance, but just to know, if the value is too low, means poor moisture or rich moisture?