bcsoverview
Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
|
bcsoverview [2010/07/31 04:58] twdorris |
bcsoverview [2010/08/02 07:33] twdorris |
||
|---|---|---|---|
| Line 13: | Line 13: | ||
| {{ http://www.ecmtuning.com/wiki/_media/samplebcs.png }} | {{ http://www.ecmtuning.com/wiki/_media/samplebcs.png }} | ||
| + | |||
| Line 24: | Line 25: | ||
| If error correction has been __enabled__, then the ECU references the Boost Target table to determine (for the same RPM and gear) what boost it should be trying to achieve at that moment. It then adjusts the base duty cycle according (up or down). It tracks this adjustment with a "trim" value, similar to the short term fuel trim. The final duty cycle used by the ECU is basically: | If error correction has been __enabled__, then the ECU references the Boost Target table to determine (for the same RPM and gear) what boost it should be trying to achieve at that moment. It then adjusts the base duty cycle according (up or down). It tracks this adjustment with a "trim" value, similar to the short term fuel trim. The final duty cycle used by the ECU is basically: | ||
| - | Final DC % = (base DC %) + WGSTrim | + | Final DC % = (base DC %) + WGSTrim |
| The WGSTrim value is a loggable variable. | The WGSTrim value is a loggable variable. | ||
| + | |||
| Line 39: | Line 41: | ||
| {{ http://www.ecmtuning.com/wiki/_media/mappinassignments.png }} | {{ http://www.ecmtuning.com/wiki/_media/mappinassignments.png }} | ||
| - | The ECU will compare current boost reported on the specified pin using the specified MAP sensor scaling against the target boost pulled from the Boost Target table to determine a boost "error". How far off the current boost is from the target boost will determine how much error correction is applied to the current duty cycle (which may have been corrected already by some amount from a previous pass!). | + | The ECU will compare current boost reported on the specified pin using the specified MAP sensor scaling against the target boost pulled from the Boost Target table to determine a boost "error". How far off the current boost is from the target boost will determine how much error correction is applied to the current duty cycle (which may have been corrected already by some amount from a previous pass through this correction process). |
| + | |||
| ==== WGSErrorCorr - Direct Access table ==== | ==== WGSErrorCorr - Direct Access table ==== | ||
| - | The table used to define how much error correction to apply is found in the Direct Access tab. It's listed there as WGSErrorCorr. It defines a correction amount (expressed as duty cycle percentage) to apply to the current duty cycle based on a boost pressure difference. | + | The table used to define how much error correction to apply is found in the Direct Access tab. It's listed there as WGSErrorCorr. It defines a correction amount (expressed as duty cycle percentage) to apply to the current duty cycle based on a boost pressure difference. A bigger difference (larger error) typically results in a more aggressive (larger) adjustment to the base duty cycle. But too much adjustment can result in oscillation. |
| If you get oscillation or you want faster response, you can decrease or increase (respectively) the corresponding entries in the WGSErrorCorr curve. | If you get oscillation or you want faster response, you can decrease or increase (respectively) the corresponding entries in the WGSErrorCorr curve. | ||
| Line 50: | Line 54: | ||
| ==== Altitude correction ==== | ==== Altitude correction ==== | ||
| The pressure sensors used by ECMLink are all absolute pressure sensors because absolute pressure is far more useful to the ECU than "boost". But the user is more familiar with "boost", so ECMLink provides an altitude correction factor to roughly translate absolute pressure to boost. | The pressure sensors used by ECMLink are all absolute pressure sensors because absolute pressure is far more useful to the ECU than "boost". But the user is more familiar with "boost", so ECMLink provides an altitude correction factor to roughly translate absolute pressure to boost. | ||
| + | ===== Options ===== | ||
| + | |||
bcsoverview.txt · Last modified: 2024/03/15 11:16 (external edit)
Page Tools
Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 4.0 International
