In section 7 of the Race Tuner manual I am following the procedure for Advanced Tuning with Dyno and AFR meter. I do not have a dyno so my data collection takes place by following the same course each time out on the street. I started with the tuning file closest to my setup, set all AFR cells to 13.2, used the data mode to collect RPM, MAP and throttle position data and my recording meter with a wide band o2 sensor for the AFR data. I adjusted the VE tables so that I get measured AFR's in the 13 - 13.2 range as best I can. No issues with what I described up to here. The problem is when I put the AFR table back into the 14.6 closed loop mode I measure AFR at idle way up in the 18 -19 range. When cruising at 25-30mph it is in the 16's. At 55-70mph on the highway it is in the high 15's and all these are after I have adjusted the appropriate cells in the closed loop bias table up to the max value.

Why would closed loop go so far lean when I have the VE set to be the desired 13.2? What is my next step to get closed loop operation richer where it needs to be?

 

Location, Location, Location.......

Where are your o2 tips located in relationship to the exhause gas inlet(Sniffer line), and where are the exhaust gas inlets(Sniffer line inlets) in location to the exhaust port?????

More than likely, your o2's are too far away from the inlets, or the inlets are not within 6 inches of the exhaust port...

FWIW, us your o2 sensors in the "Normal position", where your stock o2's are at during your datalogging session....

 

Thanks Shovelhead Bob. I understand what you are saying and I know the best thing to do would be to put my wideband sensors in the pipes in place of the factory narrow band sensors, run my tests to adjust VE to 13.2 and then reinstall the factory sensors and set the AFR table to 14.6. But hear me out with my logic. Let's say my sniffer is far away from the stock o2 sensor and even farther away from the exhaust valve. What could be the result? Some outside, non-combustion air that normally enters the outlet of the muffler comes flowing in and mixes with the combustion gas. The closer to the outlet of the muffler, the more mixing that takes place. My wideband sensor being fed from the sniffer would read a higher amount of o2 and give a false lean reading. To make my sniffer read 13.2 I would have to set the VE values to numbers that would make the true exhaust gas at the valves be richer than 13.2 so that the mix I am reading further down the pipe is 13.2. But when I then set the AFR table back to 14.6 I would think I should read the desired 14.6 since I haven't changed the location of my sensor and the amount of air that mixes with combustion gas in that area should remain constant. If not 14.6 I would expect to read a richer AFR value because the VE values would actually have the engine running rich. I guess this all really doesn't matter because my way didn't work - just the curious engineer mind I have.

 

When I dial in a bike, I always remove the stock sensors, and do both cylinders at the same time....

The problem with using a "Displaced System", like the WEGO II, is the lag time between throttle/MAP position/Load and when the sensor actually picks up the signal. Most dynos have a vacuum/forced air o2 system, so lag is different, but length of header sensor sniffer as well as composition of the tube will really screw up the characteristics of the readout.... Stainless Steel is absolutely the best to use, if you must use a sniffer system...

Seeing as you have already done your VE corrections, datalog your realtime data while riding, via SERT software... and observe your VE to New VE correction comparison... If you have done it correctly, your o2 integration should be within +/-5%....

 

Thanks again. I'll be doing some more testing. One other question... it has been hot outside (mid 90's) as I have been making adjustments and collecting data. I have noticed that when riding slow (35mph or less) the AFR will be around 14.0 but then suddenly and consistently drop to 12.2 to 12.4. Is this the heat management system kicking in? In your opinion is 14.0 too lean for cruise in the 10% throttle range, 2000-2250 rpm, MAP in the 30's?

 

Leave the Desired AFR table alone except for the 0%.... If you feel the need to take it out of Closed loop, then do so conservatively (13.8-14.2 range) . You don't need 13.2 at idle, especially when you will be going into the Closed Loop section after 0%, unless of course you want to tailor an entire Desired AFR/MAP table to your specific needs...

As far as the Closed loop cruising (10% TP), that is not bad for a stock motor....

EITMS doesn't engage until around 310-320 F, 0% throttle and NO Forward movement.... Take a look at all of your data, and compare it to the look-up tables, the MAP load and the TP will be the dominant table, so that is where the AFR is being generated, unless you have a VE cell or 2 really out of kilter....

Tuning for VE is fine for a basically stock set-up, but there is far more involved... Spark +/-, Accel enrich, decel enlean, throttle progressivity, IAC count, etc....