[BMW269]

Fact box:
Length: 4,615 mm
Width: 1,804 mm
Height: approx. 1,360 mm
Wheel base: 2,761 mm
Weight: 1,430 kg
Tank capacity: approx. 100 litres
Price: 121,500 Euro Euros (excl. VAT)
Engine type: Eight-cylinder, V-configuration
Capacity: 3,999 ccm
Bore x stroke: 92 x 75.2 mm
Compression: 12.0 :1
Max. output: approx. 480 bhp
Max. engine speed: 8.500 rpm

The M3 has 4.10 final drive and the redline is lifted up from 8.400 rpm to 8.500 rpm. For the M3 GT4 there are thre different engine control units:
-Original
-FIA (-10%)
-FIA ( - 7%)

Does anybody know the differences between these the ECUs?