Hmm, I trust what you say Andy, and it sounds like you have clearly researched the subject of using a K03 much more extensively than I have. I must admit that the foundations of my argument lie purely on looking at a K03 comressor wheel and thinking it looked like it just wouldnt flow enough air.
Assuming what you say is correct, how can it be explained that my car made such good figures on 18psi of boost, with no BV head (just an extra 60cc or so capacity) and through a carb with a 25mm venturi?
I could do with fitting a thermocouple to my inlet really to see what its running, im sure my car gets nowhere near 50 degrees though, after heavy loads I have measured both sides of my IC with an infra red thermometer and its usually around 30 C and 20 C respectively, if its high speeds on the motorway then the pipe to the carb is usually cold to the touch. Although this isnt on a hot summers day as you described.
As for the C.R, I have run my standard Spi engine at 1.2 bar and after around 5k miles of abuse there isnt a single det mark in a piston or the head. Althogh admittedly it runs excessively rich on boost and the timing has always been kept conservative.
How much ignition advance do you typically map into a high powered G40 turbo? I have a suspision that there is a lot of horsepower to be gained by obtaining the right balence of boost and ignition advance, and the more advance I can run, the less likely my exhaust valves are to drop, and the less boost I can run, (for the same power)