I'll use one of my microcontroller boards that I make - same stuff I use for robotics. I haven't decided yet on the actual display, probably an LCD panel initially. I may use a numeric LED panel eventually though since LCD's can freeze up in the cold. Eventually I'll also want to sense RPMs and average the sensor result vs RPM value over the course of a ride. When I get back home I can download the data and plot it to give the air/fuel mixture vs RPM curve that will tell me where the mixture is across the whole range under a variety of conditions.

 

Without having put much thought into it, it seems like the curve should include throttle position as the 3rd dimension (e.g. you could reach top speed in 6th gear at WOT, then close the throttle a bit without a noticeable change in speed - I'm sure a 3d graph would show something interesting). The TPS on the carb is feeding that info into the electronic ignition module, although as some people have reported, maybe it isn't that significant - at least from an ignition timing perspective.

Do you work with any general purpose microcontroller boards, or do you build your own custom circuits? I've played around with some data loggers, but nothing too serious ... mostly "Oh look! Isn't that interesting!!!" kind of stuff.

 

Not only that, but it's best to let the engine stabilize under the load at different throttle openings. Exactly how long you need to allow for stabilazation I'm not sure. That's why an eddy current dyno is far more accurate than simply accelerating on an inertia drum dyno. The eddy current dyno will allow you to set various loads in order the maintain the same RPM at different throttle openings. You can go through a full range of throttle openings for every 1000RPM for example. It allows the engine to stabilize at each setting. There's no way to do that on an inertia drum unit, which most shops use because an eddy current dyno costs bukooo bucks. My bet is your bike was tested on an inerta drum dyno which only gives ball park rich/lean readings.

 

any readng you get will be totally worthles unless ts a wideband..or you are ust trying to fin the afr of 14.7:1 ....time to buy an lm1

 

ummm .... english translation ??????

 

Here's a link my friend found after checking out this thread. http://techedge.com.au/vehicle/wbo2/

and another http://www.vortexbuicks-etc.com/tuni...%20performance

 

long story made short....unless its a wideband 02 sensor..its useles for tuning anything other than air fuel ratio at cruise...not that i'd kn0ow anything since i built my 400hp 4 banger mustang myself and TUNED myself the lm1 is a model of wideband 02 sensor made by innovate motorsports...

 

NoBrakes,

Sadly i second espacef1fan suggestion as I posted in your other thread. I attempted to tune a turbo car motor with the narrow band and as I stated it was only good for keeping me from blowing up the motor. It has the ability to read extreme ends of the fuel mixture ratios, rich or lean, but not the fine tuning adjustments your are hoping to do. The wide band sensor is what you need. However you exhaust bung should be able to handle the wide band sensor if you choose. The narrow band sensor uses 14.7 as its optimum on the guages, your goal for maximum power is not 14.7 but usually richer.

Having said that I'm interested to see how this works on the motorbike. Maybe you'll get lucky and it will be a benefit. Good luck and hats off to you going down this road.

 

Tuning with fuel injection, SDS, and/or laptop is much easier than what nobrakes has just bit off (IMO) ...

 

While I certainly won't dispute any of that, for now I don't think the more expensive sensor is necessary for me. A while back I posted my dyno run and some specifics of my current setup and its behavior over in the TT jetting forum. That forum is moderated by a fella named Eddie Sisnaro who is the defacto TT jetting expert and he gave his recommendation for what he thought would work the best. I didn't have the jets nor the needle he suggested so I had to order them. In the meantime, I hooked up this O2 sensor, but I was waiting on Eddie's recommended jets to arrive before I started experimenting too much. I did go so far as to adjust the needle I have and to drop my jet sizes a little bit, but I couldn't go all the way down to what he recommended because I didn't have them. But based on the O2 sensor reading I was running very rich - the reading was around 0.95 volts which indicates very rich. And from the response curve of this sensor, anything above that is extreme rich. So I pulled the airbox lid and saw a corresponding drop in the voltage, not much, but a little and it seemed to run better. In the meantime, my jets and new needle did finally arrive and I replaced those the other day, then put the airbox lid back on and took a test ride. The response was much better and I noted another drop in the sensor voltage output. While I know it's not the best sensor for the fine tuning you guys are talking about, I think the jetting is pretty close now. I can't take too much credit for that, I mostly just took the advice of someone else who is an expert, and someone here actually suggested I post there, so I can't even take credit for the idea of posting there in the first place. I merely stand on the shoulders of giants.

So at this point, my O2 sensor has more or less confirmed the recommended jetting, that it's not too lean nor too rich, but definitely on the rich side of the scale which is where you want to be. And with the airbox lid in place, there is a bit of room for adjustment should I find myself at higher altitudes at some point I can pull the lid and lean out the mixture a bit. I would prefer one of those thumb screws for that, but the FCR is too tall and I don't think there is room for one between the bottom of the carb and the starter motor. If in the future I want to really dial this carb in to a very high degree, you all may be right and I'll have to bite the bullet and get the more expensive wide-band sensor. But for now, I think I'm good.