High boost on 9:1 is attainable, but Aquamist and BV head are pretty much essential. The critical part is getting a decent chip.
smooooooth - no link to the chips you're selling ;-)
It's true though, the map is the critical part in any highly modified G40 motor - otherwise you may as well stick on an R5 carb and drill random holes in the jets. Steve always used to say the same, and it still surprises me how many people will spend thousands on an engine and bolt-on bits, and then run it on a generic chip that has fuelling and ignition timing miles off what it needs to be. Robin's det-prone 1341cc (stock head, non-1341cc cam) made an extra 10bhp or so on the dyno with a few minor map tweaks - still needs more, but it proved the theory.
You run massive boost, you need the ignition timing and fuelling setup accordingly. That's the main reason I bought Emerald - so I could tweak the mapping easily myself. In the meantime I carried on messing about with Digifant and got my head round the map structure.