Yes, if one is building a DeCarbon/Bilstein monotube gas shock, by design it needs to be pressurized to prevent foaming or air entry around the shaft. If you don't build it pressurized you don't get the anti-foaming benefit of the design. Also, If you don't build it pressurized, on full rebound the pressure in the bladder is actually negative with respect to atmospheric and it is functioning like a concentric two-chamber shock whereby the chambers are separated by the diaphragm rather than separated in the two concentric tubes. Full size non-gas pressurized shocks have been around like that for years but they have a tendency to foam so the DeCarbon/Bilstein gas shock style is favored in many full-size automobile or motorcycle racing settings.
For RC cars in racing settings maybe foamy is better. In fact the 'aeration shock' is based on that.
Last edited by ic-racer; 03-05-2016 at 07:12 AM.