How much coolant needed for Boxster S with Tiptronic Trans?

[KRAM36]

Getting ready to put a different water pump and low temp stat on my Boxster S with Tiptronic Transmission. I want to flush the system, but I'm not sure how much coolant I will need since I have the Tiptronic Trans. Can't find my Porsche manual either and 6 pages of searching Antifreeze, I could not find the amount needed.

So if someone would be kind enough to tell me how much coolant I need, it would be greatly appreciated.

Will be using Porsche band coolant and distilled water.

Thanks!