I think that was just a symptom of old cast piston and a big volume of air mass coming into engine. i don't think detonation as an issue as both head gaskets were ok this time and on that left bank there was a Fel-Pro blue gasket which I installed there back in 2007. But, anyway that was totally a shot in the dark as we didn't go to dyno with that old bottom end. With the new engine we will definetely do that before going to the track. It's a bit hard to figure out those wastegate settings etc. without dynoing the engine.
And, when Simo gets all the data out of a laptop, we will know more. Anyhow, that 0.52 bar pressure was present at only 4200 rpm at the end of the track. The start was at about 1500 rpm and it really didn't pick up well. Time was someting around 13.3 and we didn't even bother to pick up the time slip. Well, it would be nice to know what happened between half of the track and the end because jyrki said it started to pull quite hard at that point...
Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)