As most of you may know, the Opel C20XE motor comes in two variants.
-With a distributor running a Motronic M2.5 ECU
-With wasted spark 'group fire' ignition running a Motronic M2.8 ECU
For all intents and purposes have played around with both having owned both types of motor setup and they seem to operate in a very similar manner. So my conundrum is:
I have a late model M2.8 ECU with a nicely mapped Superchip installed without a protection board, so effectively it can be plugged into any stock M2.8 ECU without specialist help from Superchips
So if I were to plug the Superchip EPROM into the earlier M2.5 ECU fitted to my Calibra, will it function as per normal, or will I fry something?
From my understanding, the ECU only consults the fuel and ignition MAP stored on the EPROM chip when the throttle is pushed past half way, which means that it stops using info from most of the motor's sensors anyway. So there really shouldn't be much if any difference between the configuration of the EPROM maps on either an M2.5 or M2.8 ECU. That said however the earlier motors with the M2.5 ECU have lower flow rate injectors and run a lower fuel rail pressure, this means that the early injectors would need to run at a longer duty cycle to match a given AFR, so perhaps attempting this will cause the car to under fuel under load if the Superchip map was setup for the later motor?
That said the maps on most tuning chips are not set 'down to the wire' so perhaps my concerns are for naught.