In trying to debug my slow primary spoolup I found something strange with pre-control duty cycle control by PowerFC. With Datalogit I specified PC% duty cycles ranging from 60% to 100%. From my logs these settings do appear to have an effect on how the duty cycle is varying. However, the actual measured values do not correspond to my settings. For example the wastegate duty cycle (WG%) is correctly shown as 95% during primary operation. This is measured as "243/256" in the dataogit log. However, the maximum duty cycle I ever see for the pre-control (PC%) is 88% or 225/256.

Can anyone explain why the precontrol duty cycle is limited to a maximum of 88%?

 

Sorry I can't help on that as I was non-seq when I got my first PFC, and the seq cars I worked on have not had any problems with pre-spooling.

If you still are having slow pre-spool, you might change the orifice/pill size for the hose going from the #1 turbo to the precontrol solenoid. It needs to be a little larger.