Kevin

Maximum cylinder combustion pressure occurs between 5100 and 5300RPM's.. The factory Porsche mapping will ramp timing in a downward trend in these RPM's. You will also find that with stock K16's the output is limited. The stock compressor wheel start a trend of failing to meet the targeted boost request. As the boost output wains, the engine will make the power with timing.

sanyata

Well that, along with Kevins explanation, makes me feel better.... must.... resist.... bigger.... turbos.