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|
|1267355052||052 / 483||2716||S723||FD 48.3 RU|
|1267355088||088||2732||S722||FD 05.85 / FD 42.84|
|1267355220||220 — only for S/CH||2764||S720||FD 05.84|
|MAX BOOST||POWER||TORQUE||HOW TO||WHAT ELSE|
|0.4 bar / 6 psi||252 hp||380 nm||—||—|
|0.7 bar / 10 psi||300 hp||450 nm||Chip + M102 WG or M106 WG Unplugged||Boost Gauge|
|0.9 bar / 13 psi||330 hp||500 nm||Chip + Custom WG + Aftermarket Fuel Pump||AFR meter + Boost Gauge + Open Road|
|1.1 bar / 16 psi||—||—||—||—|
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. It is better to adjust wastegate spring rate, shortcut to this is M102 wastegate with stiffer 200N spring against 65N.
Note3: Rough calculation on web based survey shows that 330hp/13psi makes good use of stock fuel pump with 139ph@49psi (stock pump is rated email@example.com). See more info from http://www.raceworks.com.au/calculators/
Note4: For information on 745i Custom Wastegate project contact here. This solves main issues with original part: serviceability and upgradability.