didn't notice the spool time but yes it was random at times. At first it was boost was everywhere , somedays I would hit 18psi....then somedays only 16.....then out of the blue I would hit my target 20 psi. However it started getting consistent and only hitting like 17.5 PSI. It was driving me insane because I couldn't find any boost leaks and boost was on point when SS was tuning it for like 15 passes straight.