Early D-9s reached service without the MW 50 installation, but in the meantime Junkers produced a kit to increase manifold pressure (Ladedrucksteigerungs-Rüstsatz) that increased engine output by 150 PS to 1,900 PS, and was effective up to 5,000 m (16,400 ft) altitude. It was fitted immediately to D-9s delivered to the units from September, or retrofitted in the field by TAM. By the end of December, all operational Doras, 183 in total, were converted. From November 1944, a simplified methanol water (MW 50) system (Oldenburg) was fitted, which boosted output to 2,100 PS. By the end of 1944.