[warthog]

if I can just jump into this thread before people start throwing their teddies out of the pram!

Looking back at Simon's original post, it seems to me that by-and-large the obvious has been missed.

Simon states that his HT leads are not in perfect condition and that he plans to replace the Dizzy cap etc. Surely, these are the correct actions to methodically work through to trace the problem. If you are expecting the engine to produce more power than standard then it stands to reason that it's componant parts are being more highly stressed than in original spec. Any weakness in them is surely going to show up - possibly as a slight misfire at full boost/power.

Just a thought :)