A/F Ratio Meter via OMR

Now onto a road test/measurements for mid range @ 4k - 65Krpm is where I want the measurements for power in my build to be @ 13.5 - 14.0..
Damn OMR you might want to be careful revving your pretty bike to 65000 rpm :laugh: But really this is some good info maybe i missed it but what is the controller consist of. it doesnt look like something you made but maybe you did seems like a quick and easy way to tune your carbs.

timebomb33 wrote:

yamaha has for years have had rivnuts installed in the head pipes of most of their carburated multi cylinder bikes to allow taking individual ega readings we always tuned each carb independently at idle and part throttle settings

So now I finally figured out what in the Sam hill those nuts coming off the pipes were for. Wow you learn something every day. I was always wondering about that. :blink:

"what is the controller consist of."... Actually I did design and build this....

The display requires +5Vdc so obviously regulate it down from the battery... The switch on the right is just that, an On/Off switch that passes the battery voltage to the module box and then onto the wide band sensor heater.

Now there's more to it where the WB sensors are a 5 wire configuration... For accuracy, the VS/IP and the VS feeds are inserted into a differential subtracting OP AMP circuit...

Laymens terms, input the 2 signals from the sensor, subtract one from the other at a Gain value of 1... This is your differential voltage that is supplied to the formula...

A/FR = (differential voltage x 2) + 10

For the time being, use this displayed value in the formula and manually calculate for A/FR result... In a microprocessor circuit, this can all be coded for the display to read out in A/FR measurements... but first things first....

I've also come to the conclusion that based on our KZ charging system (my KZ ramps up to ~ 13.8Vdc charging) this would differ the readings.... I have designed and will add (once components arrives) an Adjustable voltage regulator circuit capable of 5 amps to provide a regulated & steady +12Vdc to the heater.

NOTE: Ideal systems would monitor the heater temp (currents) for keeping the heater at ideal temperatures. Thus controlling the heater On/Off as required.

I found a Bosch DATA Sheet on these LSU-4 WB sensors and what had somewhat thrown me off is the 450mV (or 4.5Vdc) in their circuit... Now I know why....

They calibrate and factory test @ 9Vdc... For desired Stoich (14.7:1), this is the mid way reference voltage.

My module meter max is presently 7Vdc @ garage 4krpm (non load). This would be out of the 0-5Vdc range you read all over the web but as I had been supplying battery voltages up to 13.8Vdc makes sense where 7Vdc is ~ 1/2 the +14Vdc supply voltage.

I'm thinking design the adjustable regulator for 9-10-12Vdc range via potentiometer or switch selection... This way I can test multiple voltages and see what the results are.

As for tuning, the plan is to always follow the method that got me here in the first place.... Old School methods of observing performances and Spark plug conditions... Lags, lulls, flat spots, exhaust popping etc...

As I have my jetting now, based on performance and plug conditions I'm fairly confident I'm real close to the desired 13.-14.0 measurement and this tool as such (hopefully) will be able to confirm this accurately...

Presently, just researching for the following reasons...
1) Would be a cool tool since I designed and built it...
Especially if it is accurate otherwise isn't worth a damn.

2) Confirming my jetting, present and future KZ's...
Here in AZ we have emission testing annual requirements.
Laws supposed to change this year but.... State wants the $$$.

3) From Old School jetting methods, insure/confirm I'm not to lean (or rich for that matter) for the search of power jetting and operations... Being as AZ get's hotter then Hell Summer, :S, I definitely don't want to be too lean...

4) My 900 is built for low to mid range performance, acceleration. At 14.7:1, better fuel mileage for sure but on this bike, naw, want the additional power that is possibly there waiting to be unleashed (if possible) without damaging my engine. Based on my cam selection, head work and carbies... I would desire the A/FR number to be more on the rich side 13.5 to 14.0...

Or as Larry mentioned, 13.8:1 would be ideal... In my build, cruise is ~ 4000-6000rpm (60-80mph)...

5) On my future KZ1000 (POS right now) I plan to keep this as the stock OEM cruiser so I would want the 14.7 ratio for better fuel mileage.

All in all, may turn into a pile of worthless crap... I figure what do I have to lose, less than a hunskie, big deal...

Then again if I pull it off.... Hmmm....

run boys theyre going tech on us again,dont worry about grandpa imin front of the pack! :woohoo:

why not build this up as a independet unit, battery and all,, I dont think you are going to be using it as a full time run system,
By making it self contained, you could control the voltage better, and not have to worry about spikes fom the bike charging system

It sounds like u have a very good handle on this Dave. I'm looking forward to your findings.

Based on Heaters requiring up to 3 amps... it would have to be a fairly large power supply and unit during a run load test...

And definitely not planning on leaving it installed after testing...

Once I get a good test run in, I then want to make measurements where rear tire raised and running under gear and get some readings... Will be interesting to see what the measurement differences will be when truly not under load...

Then there's the exhaust pipe insertion method that Dynos test the CO... Again, will be interesting to see the differences.

Again, the performance and plug conditions have provided me all the information I truly require in my jetting and build... Guess I was just bored and this seemed a another fine tune tool that I would find useful in confirming what I've learned through old school methods of jetting.

I'm not planning on making any adjustments to my jetting at this point in time until summer (AZ Heat) where I can get some additional readings for as mentioned, more power a tad rich and I don't want to be lean.

I guess I have an acquisitive mind... Ok as Plummen and Larry put it... I'm anal.... Oh wait, No, they called me an asshole that's right.... :laugh: :laugh:

For those who wish to learn something new about WB sensors...

Old Man Rock wrote:

... Guess I was just bored....

Poor OMR.

Help's on the way.

Will ramp up chit-chat a notch. :laugh: :laugh:

do u now, feel that the the Gunsun tuned carb , and the ear tuned carb match the proper AFR#'s, as indicated by the wideband measurements on the pilot circuit?
I can see that this would be a good tool to verify your results of either of these tuning methods.
the trouble i had last season , was getting color on the plugs. Therefore i abandoned this method for the feel method.
i would be curious to test, how long it takes to color a plug on a motor that is already running at the proper afr.
the longer u run on a plug the more color u can see. How dark it actually gets , depends on the AFR.
the pic i posted previously showed no color after a short period, but was looking rich after 4000 miles of use.

What are you running for fuel and what octane number Dave?

Would be interesting to change no jets but only change to a different fuel grade and repeat the test.

I have been from day one running 91 octane...

As for which fuel... not sure I understand correctly so here goes incase...

Mostly it's been either Shell or Mobil Stations... I don't usually fill up elsewhere but there have been times on out of town trips that where AM/PM type stations...

If I hear dualing Banjo's :blink: music playing at the gas pump... I keep going! :laugh: :laugh: :laugh:

"Would be interesting to change no jets but only change to a different fuel grade and repeat the test."... Hmmm, interesting thought, logic, concept... will do! Thanks bud!

And you are correct, making no chnages for quite some time, only researchin and see what measurements I come up with...

Dave

Different octane "effectively" changes your jetting. Lower octane will burn faster & could change your meter value.

I'm not saying throw some 87 in there, just pointing out he fuel situation.