745i turbo exhaust system modifications can trigger boost cut (fuel cut on boost), this chip fixes it. Chip is needed for boosting past 0.7 bar / 10 psi with stock exhaust. Original chip 1267355052 requires soldering and 24-pin socket is needed. Open-up Motronic, check original chip and circuit board id. Single chip is replaced on all Motronic versions.
Modified chips are available for labels listed:
|ORIGINAL CHIP||NEW||EPROM||LOCATION||CIRCUIT BOARD(S)|
|1267355052||052||2716||S723||FD 48.3 RU / FD 10.4 RU|
|1267355088||088||2732||S722||FD 05.85 / FD 42.84|
|1267355218||218||2764||S720||FD 05.84 / FD 10.89|
|1267355220||220 — only for S/CH||2764||S720||FD 05.84 / FD 10.89|
|MAX BOOST||POWER||TORQUE||HOW TO||WHAT ELSE|
|0.4 bar / 6 psi||252 hp||380 Nm||—||—|
|0.7 bar / 10 psi||300 hp||500 Nm||Chip + M102 WG or M106 WG Unplugged||Boost Gauge|
|1.0 bar / 15 psi||350 hp||600 Nm||Chip + Custom WG + Aftermarket Fuel Pump||AFR meter + Boost Gauge + Head Gasket and Head Studs|
Note: Theoretical max power with M102/M106 turbocharger is 360 HP at flywheel, based on stock inducer size. For extra horsepower bigger compressor wheel is needed and upgrades on fuel system too. Stock 3064G wheel diameters are inducer 48,3 mm / exducer 75,9 mm.
Note2: Unplugged / interrupted wastegate control line makes computer lose ability to influence boost pressure. Also failsafe upon severe engine knock is disabled with original part. It is better to adjust wastegate spring rate, shortcut to this is M102 wastegate with stiffer 200 N spring against 65 N.
Note3: Rough calculation on web based survey shows that 300 hp already makes good use of stock fuel pump with 126 lph (stock pump is rated 130 lph). See more info from http://www.raceworks.com.au/calculators/
Note4: For information on 745i Custom WG project contact Eric here. This solves two main issues with original part, it is rebuildable and adjustable.