The long story is that there was a good amount of time spent checking the timing, then mapping at increased revs. We had one run up where the throttle got stuck because the cruise control cable got jammed at the linkage end. This didn't happen all the other times we did full throttle, eff knows why it did it then.... This caused a slightly extended hit of the rev limiter at 6200, which may or may not have caused the failure of No.1 piston on the next run. Either way, it barely made 300hp at the flywheel at 5300 revs - so I reckon I had a duff engine to begin with..... Boost was building to 7psi, which was spot on. The exhaust ran clean, except when it hit the limiter.
We'll be looking at the No1 cylinder and going from there. Maybe a set of pistons suitable for FI will give me the results I was hoping for, but I really thought a proven ESS kit would give me no trouble. It's not a lot of boost and loads of 540i have them fitted, especially in the US.
Other good news from the day was that the exhaust sounded great. The clutch and flywheel worked well and the flywheel had no adverse effect on the idle as I had feared. The radiator exceeded all expectations by keeping the temp under 90 degrees. It's a real shame the engine let go though - we were so near to getting it MOTd and on the road properly.
Here's a video (excuse the quality), it's most interesting between 35 secs and about 1m 15 secs.
