vnt actuator on turbo charger

[Rumcajs]

In simple terms....
slow spool up rate = lower boost rise across the wide rev range
fast spool up rate = rapid boost rise across much narrow rev range

In another words having near max boost coming too quickly at too low RPM e.g. 1500 is a very fast spool up rate.
Cheers

[june]

thanks. now i know what i want to achieve when adjusting dawes/ needle valve