500 km/h could be probably reached with DB601Aa motor which had 1175PS power output at sea level at 1.45 Ata 2500 RPM.
These is 75 PS more then with 601A ( 1100 PS).
Also these data above is probably for old supercharger (4.0 km FTH).
There are data where 109 E-3 reached - 467 km/h at deck - so a few km/h more, so probably also maximum speed ( at 1.4 Ata) would be little higher then 485 km/h - about 490 km/h. It could be difference in radiator position.
These is power output with newer supercharger which rised maximum speed at FTH - with old there was 555 km/h with new one it was 570 km/h.
