Doing Z18XE?

I would like to tickle out a little more power from my Z18XE 1.8 with 90KW/ 122PS soon. There is a turbo conversion or a Dbilas suction tube with filter box, camshafts and electronics adaptation. The turbo conversion at Dbilas falls flat, because simply far too expensive. Who has already done tuning – experience with this engine? How much hp are in the turbo conversion? But the most important thing is also that the engine takes part for a long time. Do you remember the Dbilas tuning at all? What does everything have to be changed? Exhaust and brake are clear to me… What else? What would you do? Turbo or Dbilas?