Gday guys. Very new to this I just purchased a 2004 guiv zd30 manual. I have read into nads and have a boost gauge, pyrometer and provent 200 on the way but I have heard that I may need a different Dawes and needle valve set up compared to the earlier models due to a higher rate of vacuum. Can anyone shed any light on the matter.

I have never heard of that but some of the other members might be able to help. As far as I know all of the pre CRD motors use the same Dawes/needle valve set up with an exhaust blanking plate.

Thanks mate. I understand that an egr blockin plate is recommended but I am apprehensive to do so due to illegality of tampering with an emission control system. Apart from having to clean my maf sensor more often and maybe topping up oil more often what are the downsides to not blocking the egr?

Also do you notice a difference in performance and economy when blocking the egr?

EGR puts black crap through your inlet manifold and helps to block your throttle body with carbon. The black crap dries and hardens and will eventually need to be removed. Your oil also gets dirty much quicker and loses its cleaning ability.

Mine is blocked with a thin plate that is pretty well invisible although I have the pcv blowing out of a garden hose under the motor since my home made catch can fell to bits lol. (I will fix it soon.....Honest)

The turbo will spool up a bit quicker with the plate installed but its easy to adjust with the needle valve to get spool where you want it. I am running 4psi at 100kmh and getting around 10.5 l per 100km with a roof rack and all manner of gear in the back.

Dawes and needle valve are the same it is just the setting up both valves you may find that because of higher vacuum the Dawes needs to be tensioned much more (read wound in) and the Needle valve a slight touch of the adjusting knob will alter how the whole setup performs. So patience and trial/error approach will be needed to get it right to your liking.

Cheers

Edited August 27, 201213 yr by Rumcajs

Dawes and needle valve are the same it is just the setting up both valves you may find that because of higher vacuum the Dawes needs to be tensioned much more (read wound in) and the Needle valve a slight touch of the adjusting knob will alter how the whole setup performs. So patience and trial/error approach will be needed to get it right to your liking.

Cheers

Hmmm, mine is a 2003, I had to stretch the crap out of the spring and then wind it right in. A quarter turn on the needle is enuff to send the boost into the stratosphere. I will get a vac gauge one day and measure it.