WBO2-Tuning Spreadsheet

[dave w]

I can't speak directly to the logs you posted. I honestly do not have the free time to "crunch" posted data logs.

Tuning VE Tables often requires Smoothing the Peaks and Valleys in the VE Table that occur from the using the WBO2 spreadsheet. Smoothing is 3D thinking. An engine under heavy load and high RPM's require more fuel than an engine under light load and low RPM's. Kpa is engine load, an engine at 100 Kpa is at or close to WOT. The Kpa will be near 100 Kpa when the engine is being started. Engines need more fuel accelerating to 70 MPH than maintaining a cruising speed of 70 MPH. The computer interpolates VE values of the surrounding cells, so if the idle is 43 Kpa @ 700 RPM's the computer interpolates VE table values of cells 600 RPM's / 40 Kpa and 800 RPM's 40 Kpa. If the idle was 48 Kpa @ 700 RPM's the computer will interpolate cells 600 RPM's / 50 Kap and 800 RPM's 50 Kpa. As expected the VE value for 600 RPM's / 50 Kpa is lower than the VE value for 800 RPM's / 50 Kpa.

The attached has sample screen shots using the TunerPro "Smoothing" tool. I often use .55 for smoothing daily drivers. Tuning is experimenting, so smoothing with values between .35 ~ .75 are typical. Extreme peaks or valleys indicate something is VERY WRONG!. Minor peaks and / or minor valleys are common.

In a perfect world a data log would have information for every cell in the VE Table, but that would be nearly impossible to accomplish. It seems unlikely a daily driver will need tuning in the extreme corners of the VE table.

dave w