RomRaider

The boost isn't the same in 1st gear as opose to the 4th gear. I know the ECU determines the gear using speed vs. rpm [Gear Determination Thresholds] but what table defines the speed or gear target boost compensation ?

Depends on what ECU you are talking about. With the 16-bit ECU, some non-USDM ROMs have per gear boost and wgdc compensation. For the 32-bit ECU, there is no per gear boost or wgdc compensation although there is "boost compensation (vehicle speed)" which is applied only in 1st gear under the disable veh. speed. Other than that, higher boost in higher gears is due to higher load which can be tuned around (see mickeyd2005's posts).