Airbox flow rate is too low?
Kuhnke Airbox outputs are 400Nl/min(Airbox 1 & 32), and 550Nl/min (Airbox K). First check that the Airbox with its 8mm ports performs better than a similar conventional pneumatic valve. With Airbox close to the actuator, signal and flow decays due to tube runs are minimised. Airboxes also operate quicker than conventional valves.