Are you staying around the .27 bar range or is that a low starting point to be adjusted up from?
(I'm definitely not encouraging you to go higher if your system is designed for lower pressure and heat.)
Going off memory, I think other boosted FX35's have ran around 11~12 psi, (.75~.80 bar/atm)
DO NOT overboost because of my questioning. I'm just wondering why it seems low.