So that's cool if you're literally just looking to redo the ECU for fun. Seems like a lot of work though. But if you enjoy it, then more power to you
Is there an end goal here other than just trying to reverse engineer the Nissan ECU and program your own? The Z's already got push button start and you can add remote start on a manual a lot easier than reprogramming the ECU. Any other specific features you're looking to add/integrate?
I'm definitely interested in details on the computer installation. Are you just installing it in the hatch or do you have some other location in mind? I'd need something that doesn't prevent me from fitting golf clubs in the hatch.