It's all about the tangents man; that's what makes these threads so interesting. Thanks for publishing the data; didn't happen to capture any temperature relative to tune condition did you?

 

I did loosely monitor oil temp, but not thoroughly and accurately enough to publish anything concrete.

 

This was a great post. Love to see how other are adjusting their tuner and the changes they are seeing. Helps everyone.

Using the SE Pro tuner and after my VE were trued up using Smarttune and blended, I looked at timing as my power was down and MPG was low (38). I noticed the darn tuner retarded the entire F/R spark tables by 4%. After flashing it back to what it should be, power and MPG went up. Then went through the advance timing til you record timing being pulled in your data logs,etc.. Long process but I also use MY Tune to help with this.

Now I run a small cruise range AFR table in closed loop, 14.6. No ping, hitting 42/43 MPG. Pretty happy.

Again great post.

 

Thanks for the great info

 

This is why lambda is so much more accurate. Who really knows where anybodies sensors are calibrated to when they display afr. When calibrated they should be done for exhaust pressure, temp and if they are rich or lean. Does a Dynojet give the same reading as a DTT sensor? Who knows, because all they are doing is converting a voltage to an afr value. Targeting an afr of 14 with E10 will ask for an actual afr of +/- 13.64.

 

Thanks for posting your test results. Yours jibe with what I've found after working with the PCV-AT for two years and the PV since that time. The good thing about the PV is that it can provide MPG (instant and average) on the display unit, so I can watch the effects in real time.

About six weeks ago I took a very long ride in nice 80° weather, and it didn't take me long to notice that my gas mileage was far lower than I would've expected. I flipped to another gauge panel on the PV display unit that shows Lambda (AFR) for both cylinders, and noticed that it stayed at .89 (13.0:1) no matter what throttle was applied. I immediately knew that I had flashed my richer tune, the one I keep on the PV in case I ever need some extra cooling. It's set to 13.0:1 across the entire operating range. Well, what happened was that I had mislabeled my regular tune that had 14.5:1 in the cruise range, so I had to run this richer tune for the entire day. The result was 6 mpg lower (40 vs. 46mpg) than I usually see on a ride like this. What's more, both oil temp and ET ("engine temp" measured at the front cylinder head as reported by the ECM) stayed about where I usually see them, so running that rich didn't make any noticeable difference while riding at moderate highway speeds. I haven't done any comparative tests at idle (i.e., no airflow over the engine) or radiated heat at the exhaust, so AFR may affect these more than what I found in my tests.

The next day I took another long ride in warmer (+5-10°) with the right tune installed and everything returned to normal, with ET and OT running only slightly higher due to the warmer weather. The bottom line for me was that there is a big upside (mileage) to using leaner AFR's around stoich (14.68:1) and no practical downside.

A couple of years ago I did a write-up on using a hardware switch to maximize economy and cooling on the PCV with AT. When I had this setup, running 13.5:1 across the board for a base map and 14.6:1 in the cruise range in AT learning mode, I was able to monitor ET while riding with the LCD-200 display unit. I found a 7° reduction at moderate highway speeds (55-60mph) on a 90° day by running the richer base map. To me that's hardly a selling point when mileage was about 4mpg lower.

I haven't done any MPG testing with different ignition-advance settings. When I did my cam job >3 years ago I bumped my timing up in the cruise range by 3°, adjusting by "ear" and setting back 2°. IOW, I heard detonation at 5° and used 3° based on Jamie's (Fuel Moto) recommendation. My old-school idea of the best setting is as high as you can go without inducing detonation, and running there should maximize cooling, mileage, and throttle response--or at least that's my perception. Since installing the PV I've also made some adjustments at WOT based on the knock events reported by the ECM.

 

It'll adjust downward based on knock events, but not upward. The default on my bike was 8° max but I reduced it to 4° since that's as high as I've seen it in the log files.

Any flash-based tuner can adjust the max knock-retard setting (PV, TTS, SEPST, and SERT). I'm not sure about the T'Max.

 

I also have observed the fuel quality issue in my data logs, as much as .7 AFR, just by getting fuel at a different station. My tune goals are a little different than most, I basically maintan the "factory lean" type map, with the ability to keep my engine "cool" via fans, and oil cooler, I dont need to compromise my fuel economy by cooling with a rich tune. I have found the "lean tune" to be very nice performance wise, it is not noticeably "weak" as many are led to believe, it is plenty powerfull, very responsive, and natually good fuel economy. By the time you factor variance in sensors and different tuner/reader MFR translation accuracy, there exists alot of room for error in the O2 readings, All that said EFI is still 1000% better than a carb for "precise" fuel metering and delivery, even with its character flaws. Do you have any recommendations to mitigate the error or improve accuracy of the O2 sensor feedback.

 

I was hoping that you would chime in. I knew you were a proponent of the lean (relative) cruise range AFRs and wondered if you had any data similar to mine.

Your example of a 6 MPG decrease with a 1.5 change in AFR (14.5 to 13.0) is very close to the 2.55 MPG decrease with a 0.8 change in AFR (14.2 to 13.4) that I observed. Your test scenario and mine were different but the results are very similar in percent of change, and each set of results lends some credibilty to the other.

 

I run E10 since pure gas is hard to find around here. The PV Tune software has a setting for stoich, which would make you think 14.17 (stoich for E10) would be the logical setting, but Jamie told me to leave it at 14.6. I'm running open-loop and surprisingly Lambda stays very close to the set AFR (±2%).

I did run a tank of E0 through the bike several months ago and found no measurable difference in mileage, performance, or ET. It costs about 50¢'gal. more here, so I don't run it.