I don't know enough about that level of spec to give any decent advice, but reckon you and the above posting (weegaz) are on the right track, or at least sounds plausible.

Time to speak to some other tuners methinks..... Martin Hadland of Reyland Motorsport (figures/performance stat's speak for theselves, and his prices might surpirse you!) & Harvey@SCS have plenty of experience with this level of tune, or there's Stu@Motorsport Developments, Karl Norris who both use this board.

Incidentally, who spec'd/ mapped / built the engine / decided on turbo?

Good luck getting it sorted.