Today I had the idea to install an o2 sensor on my f3. i know its carbureted blahblahblah, But i came across a tutorial on making a wideband o2 sensor readout and i figured i can build and install it and get real time data while im riding as to where my AFR is at. having this would be great since i cant get my jetting just right.

I know a dyno would be best and theres a couple local shops with them, but this just has a cool factor to it
and id rather spend <$30 making the WB sensor than pay 40-50 per dyno session.

Im really just looking for opinions on this and wanna see what you guys think!

 

well you're an f3 and I'm an f4i.. I installed a wideband about about a week or so ago..

So I get real time data and can log that.. So I installed it and never did the clean air mod (stop unburnt gas/air from running back through). That solved why I thought I was running super lean at lower rpm's and lower throttle positions..

I suppose if you're tuning for WOT if it's fine.. but when you can adjust everything at different rpm's, tps positions etc.. you need far more data.. thus why I'm now hooking up another device to datalog, a/f, tps, speed, rpm etc.. graph it out and tweak my a/f mixtures precisely..

 

im just doing it to see where my a/f is at various rmps to help with my jetting.

 

as I keep logging I find out how much more beneficial data logging is. For example at WOT.. I can plot out the runs and I can see differences from +/- 1 A:F ratio, then I looked at the speed.. and realized.. one was in 1st gear, the other in second.

Makes one wonder why the aftermarket ECU's can't take into account speed or gear to additionally modify A/F. If you have the engine RPM and the speed.. the equation to determine speed isn't to difficult.

So really then.. how accurate are dyno tunes in real work applications? Unless of course the dyno has a fun blowing air in at 0-100mph?

 

Some aftermarket EMS's can, they are just really expensive. most people don't care or dont need that so to keep costs down and profits up they don't On the newer PCs ZFis you do have that ability*i think*. However, those are supplementary to your OEM EMS. Its not until you introduce a whole new EMS that replaces the OEM one that you can adjust everything.

The dyno question is a bit of a black hole; they often times (if well built, maintained; has the right sensors and a good tuner reading the data) are more accurate, and can reproduce the same scenarios over and over again. Using a dyno lets you remove as many factors - that change while a rider is on the bike - as you can keeping everything constant. Once you have a baseline with the dyno then you fine tune it to suit your needs. Its a tool, and when used correctly by an experienced tuner, can speed up the process of creating a custom map.

Correct me if I'm wrong.

 

Your right. The dyno eliminates all variables except the one you are working on at the moment. Makes it alot easier to tune and see what your changes do and lets you replicate exact conditions again and again.

 

well in response to what I'm seeing the MAF isn't doing what it should properly. I almost wish I had room to monitor every sensor.. because I'll just give you an example (I don't have the data in front of me). In 1st gear I might see an A/F at one point (I think I was near the 6k-8K band) of 12.8. But in 2nd gear when travelling at a much higher speed I get near 13.8. After this point everything seemed to converge for some reason.. but at that 3k rpm range.. I had several lines.. and I'm using the average just so I cover all scenarios.. (meaning at lower speeds I'l aim for high 12 and at higher speed I'll hope to get as close to 13.2 as possible).

To bad these aftermarket ECU's (I'm sure some do) will modify on the fly.. meaning modifying fuel based on MAF, IAT, Speed etc.. There is no way the algorithm (formulas) could be that complicated.

The timing is the freaking brain teaser.. Does anyone have dynos on a CBR of whatever type using different timing setups?