power vision auto tune basic for fm 107

[slopoke78]

i recently upgraded my switchback from a 103 to a 107, with fm flat top pistons, and woods 777 cams, the heads, throttle body and injectors are still stock.  wheni ordered my parts i also got my new map from them. my bike runs great,  although i've noticed that when watching the adaptive fuel trims, they very from around 85% to 112 %.   so i figured i'd run the auto tune basic to try cleaning up the ve tables a little bit.  after a short run using the auto tune, i hit the export learned values button, and got a message saying some of thee values exceed the 125 limit. and it asked did i want to scale the values or cap them.

my question is this,  the fuel moto tune has the engine diplacement at 117 already, by hitting the scale button the pv 2 wants to increase displacement to 124.  is this a bad idea? should i just hit the cap  value button ?

  looking at the ve tables for the auto tune session with the displacement at 124, i still have a hand full of cells at 110-120 range. is this an indication of needing bigger injectors?


bear with me, i new to tuning. i've only ran a few auto tunes on my bike and they were all with the stock engine, with air cleaner and exhaust.

if it matters any my air cleaner is a kuryakyn street sleeper 2. and i'm running a d &d fatcat with a louvered baffle.

[Jamie Long]

It is not uncommon in a strong 107 build to have the displacement constant end up in the 120's or even 130's, it is about getting a high enough ceiling on the VE table which is simply a theoretical representation of the airflow model. You will need to select cap/scale based on how many VE cells you have near/at the high limit of 127.5. If you have a large cluster of cells at 127.5 you may likely need to scale when using AT or if tuning manually raise the displacement constant (and level the rest of the table). You can also use the Charge Dilution Effect (CDE) tables in a specific RPM region to help flatten the table's out, CDE is active below approx 60Kpa, to lower the VE you will lower the CDE value by a given %, note you can also use this table to raise VE as well.

To determine if your injectors are large enough you will use the following equation: IDC = RPM * IPW / 1200, or an easier option when using Power Vision is to use the Injector Duty Cycle channel under datalog that allows you to monitor/log Duty Cycle, you want to keep this below 95%.

[q1svt]

That's some great customer service...   

[slopoke78]

thank you all for the replies.  Indeed, I definitely have to give props to Jamie and Fuel Moto.  The have spectacular customer service. They have gone above and beyond helping me with my build and tune.