Choosing the right ECU

Since my engine builder stopped working on my car due to a conflict about the time schedule, i'm free again in choice of ECU.

He guarenteed me he will got it to work, but he didnt so heres my problem:

The car is original a 2.0 4cil, DBW, FWD. The new engine is complete custom, 6 cil, and has AWD (4motion).

For the 4motion to work, my original ECU (still in the car) needs signals like load, speed and RPM.

How can i get this to work with another second ECU for my engine, and what ECU to choose? I prefer something with switchable maps (street driven race car) and flex-fuel (runs on E85, but in case of no E85 will need to be drivable on normal petrol).

To answer that question, you're going to need to know what form those signals need to be provided in. If for example the signals are an analogue voltage then you could most likely replicate them without too much trouble using a wide range of ECUs. If on the other hand you need to communicate the data via CAN then you're options are very limited. You would need an ECU which supports configurable CAN communications. You would also need to know how to decode the factory CAN data so that you could correctly replicate it.

Another option which can sometimes be simpler is to retain the stock ECU in some kind of piggy back format so that it can supply the required information. This will require a bit of messing around to decide what the stock ECU needs to see to be kept happy but it's a viable option sometimes.

The second option was how we where thinking :) Using the stock ECU just for the needed signals :)

Because its a fully CAN operating car.

You'll need to check what you'll be able to control in a piggy back form without CANBUS communications as the AWD control might flake out and not work as it should. Would you be able to get your hands on a canbus decoder?