I have found the problem !!! It was a software issue
Never shown up before as most people that run 8 injectors, run laggy T4's
that dont generate boost until the rev limit
I was correct, the ecu is predicting the rev rate rise too fast.

I am just modifying the software, can you send me email address
to simon@s8ecu.co.uk and I will send the update programs within an hour.