What's the max boost for a ZD30?

Forgive me if this has been dealt with before but couldn't find an answer in older threads.
What is the max the boost should read for my '02 gu3 3.0L? Have just had a reco ZD30 installed. Done about 1600k. Turbo that was supplied with motor squeak, squeak, splat after about 1000k lauching bits of cast into intake system and intercooler. Since replaced it with genuine Nissan Garrett turbo.
Going by the boost gauge it reaches >20 psi when the foot goes down, levels out about 10, then drops back to around 5-3 psi.
Appreciate any wisdom on this. (EGR is blocked also)

Someone will be along mate to assist - I know I've seen this on here before also, so no doubt there's some experience in this space. Hang tight!!

If you have the standard boost control system in place you boost will be all over the place as the computers varies it for EGR operation etc. Ideally 16Psi is the maximum boost and for best results a lot of ZD30 owners fit a Dawes and needle valve set up to manually control boost.
With your EGR blocked it would be best for your engine and turbo to have the manual boost control.

If you haven't already have a read of this thread; http://www.nissanpatrol.com.au/forum...ghlight=gren02

Tony

Cheers, Bigrig.
Driving it with a degree of caution at the moment. This is the third motor, maybe going for a fourth depending on the implications of feeding it a handful of metal pieces when crappy chinese/malaysian turbo let go. We live. We learn. Cheap doesn't mean in-expensive.

OK... very little info but sounds like it is spooling up too quick and/or overboosting and going into limp maybe? How did you go about setting up the VNT Actuator?

You could try just backing off the VNT and see what happens or head for a dyno. I saw spikes of over 20 PSI on mine when I blocked the EGR but mines a CRD.

Ideally the max boost should settle at around 16 ish and highway cruise somewhere between 8 to 10 but a lot of variables in that number... 10 PSI and then 3 to 5 is way too low

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Originally Posted by Mad4Mud

Cheers, Bigrig.
Driving it with a degree of caution at the moment. This is the third motor, maybe going for a fourth depending on the implications of feeding it a handful of metal pieces when crappy chinese/malaysian turbo let go. We live. We learn. Cheap doesn't mean in-expensive.

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I'm surprised you didn't drop in a TD42 after the second engine failure!

Tony

Nice one, Tony. Recently purchased EGT gauge. Yet to install it as I'm kicking around the idea of a 3" exhaust. A catch can's the next project, I think. Was thinking of un-blocking EGR and doing some comparisons. Any thoughts on whether to bother or leave it blocked?

The 4.2 was looking a mighty fine option. lol. The 2nd motor was a roughy some mates thru in on the cheap to get me mobile again. Was also the spike on the learning curve. The third and current motor is a full reco that'll keep me out of the property market for another year or so. Nothing succeeds like persistence (I hope). It's either that or a case of, "you can't fix stupid"

Quote:

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Originally Posted by Mad4Mud

Nice one, Tony. Recently purchased EGT gauge. Yet to install it as I'm kicking around the idea of a 3" exhaust. A catch can's the next project, I think. Was thinking of un-blocking EGR and doing some comparisons. Any thoughts on whether to bother or leave it blocked?

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Having seen first hand how much crud builds up in the inlet I would definately leave it blocked and fit the catch can ASAP.

Tony

Thanks to "The Evil Twin" . When i installed the new (genuine) turbo I'd never heard of vnt was thanks to this site i got clued up. Initially it was boosting off its head. Wound vnt screw in half way, reset computer, boost was way low. Repeated procedure winding screw out a little. That's where i'm at today. Almost 100% certain it's not going into limp mode, if i understand what i've read correctly.
When I first got it back on the road I did get it put on the dyno after the first oil change as I was pretty disappointed with its lack of response, power, take off, performance, blah, blah. The diagnosis was replace crap turbo for genuine and bring it back for another look. All well and good except it's a pricey exercise every time to get it dyno-ed. Still got issue of steel filings in oil filter after first change to deal with. Assuming its all related to crap turbo shedding some bits and pieces down the guts. Oh well. It's better than being bored.