Important application notes – AEM Infinity Supported Applications - BMW 1995 E36 M3 User Manual

Page 3

IMPORTANT APPLICATION NOTES

The test vehicle used for development of this app was an E36 318 sedan with a full S50usB30 swap from a US
spec 1995 E36 M3. The S50usB30 engine is different from the Euro spec M3 engine in that is does NOT have
ITBs or dual continuously variable VANOS. The S50usB30 engine has a large plenum style intake manifold with a
single throttle body and on/off style VANOS on only the intake cam. The S50usB30 engine appears to be nearly
identical to the standard M50tuB25 engine with the only discerning difference being the engine’s displacement
(3.0L versus 2.5L). Both engines from the models listed above use Bosch DME part number 0 261 200 413.
Operation of the Infinity EMS was not verified on the M50tuB25, however, because both engines use the same
DME, both have the same wiring harness pin out and use the same injectors and cam/crank/CLT/IAT sensors.

The injectors used for testing were stock “green top” Bosch injectors (part number 0 280 150 415). These injectors
are undersized for the application and are marginal in providing enough fuel flow (156cc/min @ 50psi) to support
the stock horsepower level. The stock DME runs a high load WOT AFR of 12.8:1. While creating the Infinity base
session, targeting a slightly richer AFR of 12.4:1 resulted in hitting the Primary Injector Duty Limit (Plug-
ins>Wizards>Setup Wizard>Diagnostics) value of 95%. It is highly recommended that replacing the stock
injectors with higher flowing injectors be made a priority in order to support any kind of performance modifications
made to the engine.

The S50usB30 engine uses a Bosch 3-pin PWM idle air control (IAC) valve. The 3-pin IAC is driven by a standard
PWM signal as well as an inverted complementary PWM signal. An external circuit is required to invert the normal
PWM output signal as the Infinity is not outfitted with hardware to support this function. A

schematic

to build this

device is provided in this manual.

The E36 M3 uses a Mass Air Flow (MAF) based injection control strategy in stock form. The base sessions and
configuration files provided are set up for Speed Density using an AEM 3.5Bar MAP sensor (PN 30-2130-50). The
stock MAF sensor is not supported in the provided configuration files. The stock CLT & IAT sensors have been
fully characterized and their calibrations have been inputted into the base session.

The adapter harness used to mate the Infinity EMS to the stock wiring harness was set up to use the stock main
relay that is already on the vehicle. The stock coolant temp gauge is not supported by the Infinity.