ZD30 HPD boost HPD Dawse Valve VNT Boost Controller can I just add needle valve?

[JD7902]

Hi guys I just bought a 2003 gu 3.0 diesel which came with HPD Dawse Valve VNT Boost Controller pre installed. Im wondering if i can just buy a needle valve from tillex and add it to the set up? If so where would I add it to the all ready existing dawse valve set up.

Also what boost pressure should I be setting the contoller to? It goes up to 11 or 12 pounds of boost for a second then drops and stay at 10 pounds under load right now. Should I increase the boost as ive seen people say 13-14 is normal?

Cheers

HPD contoller https://patrolapart.com.au/product/h...61-zd30-models
needle valve https://www.tillix.com.au/product/ne...ol-rate-valve/

[Bidja]

@JD7902 I do not have first hand experience with this HPD Boost Controller, but it appears it is only to adjust for max boost without a spool rate means of adjustment.

Guess you want to add the Tillix needle valve to be able to adjust for different spool rates, adjust for turbo lag and to hopefully obtain a reasonable cruise boost level / running reasonable EGTs?

If this is the case, IMO, YES u can buy the Tillix needle valve, pick up fresh air feed/supply from air intake side, connect it to the needle valve and on the depicted flow "vac arrow" side, this is to be T'd into the vac hose running from HPD boost controller to the VNT actuator. Should be able to adjust the needle valve (open/closed) with eng at idle and observe when the VNT actuator rod moves (up/down), adjust so that the VNT lever just rests against the stop screw (eg: VNT vane aperture position). Good start point.

With regards to Target Boost level _ should be able to increase incrementally to say 14-15psi successfully without experiencing limp. Yes to be set with engine under load. Would initially set Target boost with needle closed and then start to open to where the lever just rests against stop screw. Then u may need to turn the controller adjuster CW to regain the 14-15psi max boost.

Saw that u asked this question on another forum, come back and let us know how it goes as would be interested.

BTW drop by the intro section say G'day.

[Bidja]

Deleted as double post

[mudski]

The HPD controller is just a boost limiter and thats it. Same for the Tilix and also the Dawes. To control the spool up rate you need to add in a needle valve. This simple bleeds air into the vac line to the actuator (from memory tis' where it goes).
As for max boost. My old 3Ltr Di used to limp out at 16psi on the dot. Put the HPD hi flow Billet air box lid and MAF housing on and I could see 25psi without issues. In the end i had it running at 22psi max boost, she went real good for what it was.

[pollenface]

I have only the HPD boost controller installed, no needle valve, tuned on a dyno @ 18.5psi, have no desire to add needle valve.

[Bidja]

@JD7902 something weird happening, just saw your last post but seems to have disappeared (deleted)_7.50pm.

Copied content from the email notification:

"Hi bidja Ive just installed the needle valve to the set up. Ive set the valve to rest on the stop screw on idle. I now been doing power runs up hills in 3rd and the car seems to be limping out at around 3000 rpm but would return back on the power when releasing the throttle and getting on it again. It seems to do it at whatever psi I set the controller to had it at 15 psi it did it, also down to 11 psi would do it also. is this normal? if not any ideas to fix it? I have a DI motor"

Case of Limp for sure. MAF voltage must exceeding the time threshold allowed by the ECU. Normally u can reduce the boost and this does fix the issue but if it is occurring down to a max boost level 11psi, wonder if the MAF sensor is faulty.

Try connecting the vacuum hose that is going to the Boost Controller, directly to the turbo VNT actuator (bypassing boost controller and needle valve) and go for a gentle drive. Note: For safety sake do not boost higher than 15psi.

Guess u are using a scan tool, any codes reported (record them) and delete if any before test run.

I recall u saying that before fitting the needle valve and when using only the HPD boost controller u were running max boost 11 psi, wonder if something was wrong when u bought the DI.
Take it for run with vac hose connected direct to actuator and let us know result _ but take it easy.

[JD7902]

Hi bidja bit weird that they deleted my post. Anyway I cleaned my maf, replace all my vac lines and backed off the boost controller alittle bit. Now I can get up hills in 3rd without experencing limp mode making 13-14 psi at around 3000 rpm. Im pretty happy with where it is at. Cheers for all the help and insight legend!

[mudski]

FYI, that Tillix branded needle valve is a $5 (if that) made in Chyna valve that is not very accurate. I used to sell all these bits and bobs in a past life time. If you want a decent needle valve. Find a Tognella branded one.

[Bidja]

Hi bidja bit weird that they deleted my post. Anyway I cleaned my maf, replace all my vac lines and backed off the boost controller alittle bit. Now I can get up hills in 3rd without experencing limp mode making 13-14 psi at around 3000 rpm. Im pretty happy with where it is at. Cheers for all the help and insight legend!

Did u install the needle valve?
Should be able to run 15psi @ 3000rpm / 3rd gear hauling w/stock ECU _ wind it up a little (small bits at a time).
Did u try vac line connection direct to actuator (bypassing manual boost controller)?

Can still improve on this mate