ECU not recognized by AIM Data acquisition?

Tuner folks,
I bought a track ready e36 M3 arms-length from the builder, through a dealer. Very nice ride, was advertised as having a Z3-M s52 motor installed for the build, runs great. This "appears" to be correct, dynos at 268rw. Funny thing is that the ECU VIN comes up as coming out of a 1994 325iC with a 2.5L engine (?). That's 3 different years and models between car, engine and ECU Since it does run great, any thoughts on why a builder would do this? Also and pro/con on getting the correct ECU for this engine so the AIM data acquisition system will recognize it? Thanks in advance for insights!

Originally Posted by anjindd0t

Tuner folks,
I bought a track ready e36 M3 arms-length from the builder, through a dealer. Very nice ride, was advertised as having a Z3-M s52 motor installed for the build, runs great. This "appears" to be correct, dynos at 268rw. Funny thing is that the ECU VIN comes up as coming out of a 1994 325iC with a 2.5L engine (?). That's 3 different years and models between car, engine and ECU Since it does run great, any thoughts on why a builder would do this? Also and pro/con on getting the correct ECU for this engine so the AIM data acquisition system will recognize it? Thanks in advance for insights!

That model year (1994) has an OBD 1 computer and fuel injection system. The S52 was an OBD 2 engine. It is fairly common to convert S52 engines to OBD 1 and install the intake manifold from that era. It flows better at high rpm than the OBD 2 intake manifold. The common ECU used for this conversion is the one used with the 2.5 liter engine that came in 325i and 525i cars from 1993-1995. A tuner chip would have to be installed in the OBD 1 ECU to run the S52 and the most common ones are from Turner, TRM, and Active Autowerks IIRC. I don't know anything about the AIM data acquisition system but if it relies on an OBD 2 connection, you won't be able to do that. Converting your race car to OBD 2 is possible but will be a fair amount of work. You will need the proper engine harness, sensors, throttle body, mass air flow meter, and ECU. You will also need to have the ECU modified to eliminate EWS starter interrupt.

Thank you very much mda185, that 'splains it. Will leave it alone then as it runs just fine the way it is!