Boost Controllers for Vacuum Controlled Turbo's

[Bizzle]

Somebody please explain because im TOTALLY confused.
I thought I was pretty "up" on turbo's after having numerous turbo Japanese cars. However, I have recently purchased a Nissan Patrol (Y61) big 4x4 with a 3.0ltr ZD30DDTI engine (turbo diesel) and im in the process of blocking off the EGR. I also wanted to fit an electronic boost controller as it will let me set the boost on the car to a solid 15psi no matter what conditions (a common catastrophic issue on a ZD30 engine is over-boosting due to an ECU fault/MAF malfunction etc) So it’s a nice safety measure as I do a lot of towing with the truck.

Now, im told that the ZD30 uses a vacuum controlled turbo, so I can’t use any of the electronic boost controllers i would normally use on the likes of a Skyline (RB25/RB26 engine) because they are designed to bleed off positive pressure rather than vacuum?

Does anybody have any info or experience with this?

Im lost.

Thanks

Chris

EDIT: This is a VNT turbo by the way

Edited by Bizzle on Thursday 7th May 17:15

[v8guinness]

VNT turbo's on Diesels work quite differently to turbo's on petrol engines, or at least the boost control does... if you manage to generate a fixed vacuum you will fix the vane position, not the boost, this will make it an unregulated fixed geometry turbo... not a great move... you risk over speed / over boost at high speed/load.
The VNT allows the turbo to respond more quickly, but also limit the maximum boost...

I'm sure there are How it works type explanations somewhere on the internet...

[Bizzle]

Humm right...
So you really do need to use a dawes device/ball valve.

Interesting...

I'll try and find that "how too"

Cheers