Hi Alex
Yes this is normal as part throttle has a few things to stop it making too much boost and for holding for too long. There is a load table for part throttle, this is much lower than full throttle so you feel the car accelerate hard then it stops when it hits the load table, when this happened the ecu opens the turbo actuator to drop some boost, then it will build back. If the actuator pre load is too strong this is more obvious also. The reason for this is in the RS full throttle is pedal 80% or more so less than this the fuel is lambda 1 / stoichiometric 14.64 to 1 and if you make too much boost for too ,long you will damage the pistons and get detonation as part throttle is lean compared to wide open throttle, trust me this is better this way. I personally don’t drive like this holding 50% it’s better to keep adding throttle gradually.
Race mode can feel faster as the suspension allows the power to be delivered to the road better and feels more direct.
Enjoy
Kommt von DS.