Originally Posted by mikem
What is the stock compression on the N54 Tony and how much boost can you run without needing helpers to avoid detonation? I remember reading that Alpina lowered the compression with their pistons but I guess they have to avoid warranty claims from people who might run low octane fuel.
Alpina do not use the OEM pistons but install forged pistons from Mahle, which allows them to lower compression without sacrificing power output. Those pistons are rather expensive, though, I got a quote on them for around 2000 EUR.