Wideband tuning?

[80GS1000]

Anyone here had experience with tuning a bike or car/truck with a wideband system? Seems like it'd make carb tuning a lot easier since you'd know instantly what the air/fuel ratio is at any given throttle position so you can get the jetting dialed in perfectly in real world conditions.

Installation seems pretty easy as all you'd have to do is cut a hole and then weld a bung (huh huh Beavis, he said bung) to your header or midpipe for the O2 sensor, then provide a power source for the controller and a/f gauge.

Also seems cost effective as the whole system is the same price as 1.5 hours of dyno time and you can do it on your own schedule, not the dyno shop's.

What's the ideal air/fuel ratio for the pilot, the needle, and main circuits?

 

[Nessism]

Seems like a good idea to me. I'm not real familar but my understanding is that the readings are dependant in part on where the sensor is located.

Regarding the best mixture ratio, I think the ideal situation is to maintain the same mixture ratio all though the power band. Approx. 13:1 is where max power is, so that's a good target.

 

[first timer]

ideally you would want a bung on each header pipe so you can tune each carb. I was thinking of this myself but have such a long list of other things to do first.

 

[four_shot]

x2
though I'd think they're ugly on an exposed header like ours. on a cage, they're indispensable.

 

[Loose Seal]

I tuned my old car with an Innovative LM1 and have a Zeitronix for the current car, you could definitely do something similar with a bike. With something like Innovative LM set up, the sensor is clamped to the exhaust and the display is handheld (though would be easy to temporarily mount). I wouldn't go through the trouble of a permanent installation on a bike unless you have special circumstances.

I would make the same assumptions on a bike that you would with a car in this case. Tune off the total reading. Don't make it overly complicated with sensors and displays for each runner.

I would also go with an AFR a little richer than 13:1 most likely. Given the higher abuse and air/oil cooling, a richer mixture should be better to run safely regarding temps and detonation. Contrary to some thoughts, you're generally getting more power with a little more fuel opposed to running on the edge of lean.

I would think the AFRs should go from slightly richer to leaner as you go through the carb circuits.

All of this rambling aside, I have no idea what these motors typically run for AFRs and would be interested to see.

 

[curseboy]

I wonder if It'd be useless to tune without a dyno, and I don't know if "road tuning" is practical on a motorcycle.

 

[rcp]

Anyone here had experience with tuning a bike or car/truck with a wideband system?
[...]
What's the ideal air/fuel ratio for the pilot, the needle, and main circuits?

Did you get carbs yet? If so which ones? You were looking for flatslides and GSXR CVs, right?

Let met state: I have no experience with these. I can offer some links I've used for research. (Oh, and if you can tell when you're only on the pilot and the needle, you're a better man than me.)

Carburetor tuning for non-CV carbs
Factory Pro's Tuning Procedures for Slide operated, non-CV carbs which says "Do NOT tune to A/F Ratio - most slide carbs will not deliver best power or response at 13:1 A/F Ratio" - they're after absolute max power, mainly for racers. Up to you to decide if that's what you're after or just a fairly well-tuned street machine.

Keihin FCR tuning manual if you want, skip to the part with "Nobody likely to be reading this page can afford a four gas EGA" to get to the wideband bit.

Exhaust Gas Temperature/Power vs Mixture in aircraft engines:

This graph was a bit of a revelation to the author of the FCR manual above - he didn't know the EGT dropped off again when you continue to go leaner than max power into the range marked best economy.

K&N's narrow-band sensor has some numbers:
http://www.knfilters.com/airfuelmonitors.htm

Bungs available here:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=NGK-91301

More reading:
http://en.wikipedia.org/wiki/Air-fuel_ratio
http://en.wikipedia.org/wiki/Air-fuel_ratio_meter
Factory Pro on CV carb tuning

Hope this helps, please let us know what you end up with, I may be going this route soon too.

- Richard

 

[waterman]

Some time ago, possibly years, someone here was trying to install an oxygen sensor on their exhaust to help with tuning. I just remember the thread as a trial and error test to get an accurate reading. Not sure what to search, but maybe someone else can confirm this:-k. Seemed like a neat experiment.

 

[Guest]

I have a JAW (just another wideband) controller that I will be installed on my bike as it gets completed. I think the website is www.14point7.com

 

[80GS1000]

Did you get carbs yet? If so which ones? You were looking for flatslides and GSXR CVs, right?

[tons of great tuning info]

- Richard

Thanks for all the great info and links. Wish I could afford some aftermarket carbs like the RS Mikunis but in the mean time will be using the stock 34mm Mikuni CVs. What carbs are you using?

The best deal out there seems to be this system - comes with the 02 sensor, the controller, and the digital gauge.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=170314324245&sspagename=STRK%3AMEWAX%3AIT&viewitem=

There's a kit with a smaller gauge that might suit bikes better, but it's ~$70 more:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=390039042710

 

[Old Colt]

I have a fair amount of experience with wideband tuning. I now use the Tech Edge units exclusively. http://wbo2.com/

After years trying to get mid range stumbles out of carbs, guessing if the stumble is a lean spot or rich. The guessing is over. Those short quick changes in mixture can be seen so dang easy now.

About 10 years ago I started soldering up the DIY wideband units that are associated with the beginnings of Megasquirt. Then living with the constant failures of the LC-1 and the non linear Zeitronix I now have settle with these sweet Aussi made units.

I had installed 6 of the kit 2J units from Tech Edge, but now they have the 2J1 premade units with an assortment of displays available. I have bought and installed 4 of them now.

My opinion, buy a wideband of your choice, install a bung down in the collector and have at it. You can dial in your settings so fast whether you are on a dyno or street tuning.

 

[Guest]

I prefer the trial and error method.

NOT!

 

[duaneage]

Installing a O2 sensor would be the first step towards fuel injection.Something to think about down the line.

 

[asetech]

You could just by an o2 sensor from the parts store and use your dvom.weld a bung to each header pipe and tune each carb 1 at a time then cap the bungs that you arent using.

 

[Old Colt]

You could just by an o2 sensor from the parts store and use your dvom.weld a bung to each header pipe and tune each carb 1 at a time then cap the bungs that you arent using.

There is a major problem with this approach. The narrow band sensors are just a switch, they tell you if you are richer or leaner than Lambda. But they do not and can not tell you how much richer or leaner since they are non linear nor temperature stable. The old theory of looking for .8 volt is meaningless.

With a separate carb per cylinder there is little to no value in installing separate sensors in each exhaust. This used to be done to find imbalanced flow and distribution in intake manifolds but with the fast electronics this can be done with one sensor now. This is common in todays cars to determine which cylinder needs correcting or may be developing an issue inducing a misfire. Basically they look at time periods when changes happen to determine which cylinder is having problems. A bit beyond what we have available at this time.

More common to check for variation between cylinders are the use of thermocouples. But getting repeatable results is hard to do. The thermocouples vary ? 150? and are sensitive to the position and depth installed in the pipes. And they really need to be recorded to determine any trends.

 

[first timer]

There is a major problem with this approach. The narrow band sensors are just a switch, they tell you if you are richer or leaner than Lambda. But they do not and can not tell you how much richer or leaner since they are non linear nor temperature stable. The old theory of looking for .8 volt is meaningless.

With a separate carb per cylinder there is little to no value in installing separate sensors in each exhaust. This used to be done to find imbalanced flow and distribution in intake manifolds but with the fast electronics this can be done with one sensor now. This is common in todays cars to determine which cylinder needs correcting or may be developing an issue inducing a misfire. Basically they look at time periods when changes happen to determine which cylinder is having problems. A bit beyond what we have available at this time.

More common to check for variation between cylinders are the use of thermocouples. But getting repeatable results is hard to do. The thermocouples vary ? 150? and are sensitive to the position and depth installed in the pipes. And they really need to be recorded to determine any trends.

HUH? I am confused, these displays are complicated enough to display the reading of each cylinder when the o2 sensor is mounted at the collector?

It could be done in theory but would require the gauge to data log as well as be tied into the ignition, but that get real tricky since our ignitions fire every revolution. Either you would have to pull the data and look at it in a chart to see what each cylinder is doing before you could tune or have a switch on the gauge to change cylinders. By tying to the collector and reading a simple gauge you are just reading the average A/F of all 4 cylinders (which isn't a bad thing).

What is the recomended distance to mount a bung from the exhaust port? I have seen on stock Ducatis/Aprilias bungs mounted about 6" from the exhaust port on the header pipe. It seems mounting down by the collector would be to far away, don't the O2 sensors need to be right in the flame?

What is so wrong with getting a finer tune and using the wide band hooked up to each header pipe one at a time and tuning each carb? Is this just micro managing the carbs? Can the mix for each carbs be that far off? How much adjustment can you make on carbs? I doubt you are going to be able to dial your carbs in that finely once you go past the needles unless you start drilling your own jets.

 

[rcp]

Thanks for all the great info and links. Wish I could afford some aftermarket carbs like the RS Mikunis but in the mean time will be using the stock 34mm Mikuni CVs. What carbs are you using?

Will be using VM33 Smoothbores. No flatslides allowed as they're out of period.

- Richard

 

[Old Colt]

With the wideband units on the market you will not be able to differentiate between cylinders. It is in the fuel injection world that is done.

A wideband sensor should not be mounted close to the cylinders. These are heated sensors and the feedback loop would be driven nuts trying to manage the sensor temperature.
Narrowband sensors can be mounted closer so they warm up quicker and since they are not temperature stabilized it matters less.
Do not confuse the heated narrowband sensors with a wideband sensor, there is no similarity in operation.

Again, there is no value in using 1 sensor per cylinder on a performance bike engine. You have one carb per cylinder.
There is some variation in the intake ports between centers and outers on most of these engines. And the center cylinders will not cool as well as the outers.
That is all that would need to be compensated for.
The only other variable is in the exhaust system and if it is causing any variation it should be discarded and a proper one installed.

Also keep in mind when tuning an engine, mixture is not the final thing you tune for. It is a guide but you need to tune for torque. Different combustion chambers call for different amount of fuel to make power. The wideband is just a tool that allows you to understand what is happening and can not tell you what you need to do to make power.

I was just working with a vintage BMW car that due to the massive dome on the pistons, cruise mixture could not be leaner than 13:1 yet most 4 valve and some 2 valve engines can cruise at 17:1 mixture. The same variations are there when making power. I have seen 2 valve normally aspirated engines that need more fuel than some turbo engines at full chat.

 

[Suzuki_Don]

Some time ago, possibly years, someone here was trying to install an oxygen sensor on their exhaust to help with tuning. I just remember the thread as a trial and error test to get an accurate reading. Not sure what to search, but maybe someone else can confirm this:-k. Seemed like a neat experiment.

Try the FLYING BANANA link from Perth, OZ.

http://www.theflyingbanana.com/dyno.htm

 

[80GS1000]

A couple of questions regarding mounting the 02 sensor on a bike:

Where's the ideal place on a 4-1 or 4-2-1 header to mount the O2 sensor? Can you mount it to the midpipe before the muffler?

How much electrical draw is there from the heated O2 sensor? Does the GS charging system have enough juice to leave it plugged in full time, or should it be disconnected after carb tuning?