New developments on the operational designs of the GT28’s. We will revamp the EBV actuator to allow for higher “pre-transition” boost. The stock actuator is not able to handle the increased boost that these turbo’s develop, Our goal is to have about 1Bar actuators (14.7psi). This will allow the boost to rise to 14.7psi during the pre-spool area between 3200-3800rpms. This can replace the need for an electric or manual boost controller.
We have also noticed that with these larger turbo’s, the transition point needs to be changed. I have designed a new circuit that will allow users to lower or raise the RPM level at which the transition starts to operate. We are thinking this to be in the area of 4200 to 4500 rpms. This will allow the 2nd bank to raise its boost output equal to the 1st bank output (now at 14.7psi) So instead of 3800 rpms and seeing a significant boost drop, moving to 4400 rpms should eliminate the boost drop. More seamless.
Here are a multitude of boost by RPM data I collected in the last month. Most all were under 5000rpms since all I was logging was the transition. I tested 1) Stock EBV system, 2) Manual Boost controller in the EBV system, 3) My new electronic boost controller in the EBV system. My results were a modified EBV actuator operating in stock fashion, produced the least boost drop. Although I was only testing a 12 psi actuator, and not a 14.7psi actuator.
