As said yours is Ford EEC management, this is a limitation in terms of tuning compared to the Weber management of the rest of the family, as obviously is the small turbo.

I don't think it contains an EPROM (Chip) which would explain why you can't do so.

The way the software is usually changed on these ECU's is by plugging in a module into the 'J3' socket.

That, or you would have to "reflash" the internal memory.

I think 320HP is a bit optimistic imo, I think around 300HP is a more genuine figure.

Martin