Hi guys, recently got my car back from being tuned. Running -7s, built motor, bosch 023 and 1000cc injectors. Boost controlled through an evc6 (not tuned for rpm/throttle) and tuned for max of 22psi with adj cam gears (stock cam) and making 340rwkw.
Im currently experiencing really bad surging at partial throttle in the high gears whilst under light boost (3-4psi) and also quite bad spiking (regularly see peaks of 24.6psi). To put it technically, its going shhh-tututututu whilst under boost partial throttle
I also have an aftermaket "twin turbo pipe" with longer piping before they merge. My Wastegate boost source is also tee'd off this pipe.
Any ideas what could be causing this? Is it likely to be the tune? Also is it ok to expect that the EBC would be tuned to take advantage of its full capability (i.e. Tuned for speed/rpm/throttle as well as just max boost/offset)? I was charged $150 to tune the ebc on the dyno in addition to tune costs