Manual boost controller zd30

Dave
The pressure drop will be proportunal to the RPM squared so the question has no simple answer. Eric.

Hi Dave,
We only use these pressures as a guide. I personally doubt if you would have any noticeable difference in pressure before or after the cooler, but this can depend on any restriction in the cooler. Having the gauge fitted after the cooler will give you a truer indication of what’s going into the motor, but a good non restrictive cooler should do the same. Also you could find similar differences between two different boost gauges.
Depending on whether you’re tuning for performance or durability will determine your setup. I’ll presume durability, so the important thing is to limit your maximum boost to around 18psi @ 4000rpm. Then adjust the needle valve to limit boost to 6psi @ 1500 and about 10psi @ 2000rpm. From 1500 rpm your boost should be linear to 16psi @ 3600rpm. This is the ideal boost curve because the ZD30 makes maximum power @ 3600rpm and it makes no more over 16psi.
After fitting the manual controller and bypassing the VNT control solenoid, you’ll find that boost is mainly determined by engine rpm and not so much by load. This is better for turbo and engine life although there is now a compromise between boost and EGT’s. If your EGT’s are too high, you should increase boost slightly at lower rpm.

Chaz