Merlins Ralliart and EvoX TUNING GUIDE Version K.pdf - EvoScan

MERLINS RALLIART & EVOLUTION-X TUNING GUIDE9.06-BOOST TUNING - BOOST ERROR CORRECTIONThe table is used to correct the boost control solenoid (BCS) pulse duty cycle to getthe actual load to match the desired load. Shown below are three variants, from leftto right: stock EvoX, stock RALLIART and GST tuned RALLIART. Note that the errorcorrection only operates on the “Reactive Solenoid Base WGDC Maps”. Both theRALLIART and the EvoX have the reactive tables, only the EvoX has the passivesolenoid.Figure 55:BOOST TUNING – BOOST ERROR CORRECTIONWhen the engine is idling or cruising, the BCS is at 0% WGDC. When the enginestarts boosting and the load exceeds the MIN LOAD for BOOST CONTROL point, theECU sets the BCS pulsing with a duty cycle from the BASE WGDC v RPM 3D map. Atthat point the ECU compares the actual load to the BOOST TARGET ENGINE LOADmap (plus the BOOST LOAD OFFSET) and makes an appropriate adjustment to theWGDC to the BCS.The rate at which the tracking check is made is set by the ERROR CORRECTIONINTERVAL timer. The stock value of 10 results in a correction interval of 1000mSbetween adjustments to the WGDC. This interval can be shortened to providebetter boost control, a value of 3 gives a correction interval of 300mS and is a goodsetting to use with three corrections per second. By shortening the interval, theECU will much more rapidly respond to load deviations from the target load value.Recommended minimum value is 3-4 for faster boost error tracking. Note thatwhen using a reduced correction interval you should also reduce the BOOST ERRORCORRECTION table values to prevent over correction as the system will now haveless lag and is effectively more sensitive.Figure 56:BOOST TUNING – ERROR CORRECTION INTERVALREV: 0.K merlin@three.com.au Page 81 of 134