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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #1
Thank you for bringing another interesting mod I would not have conceived of off my own bat!
At present I'm relatively happy with my dawes/needle setup compared to what it was like standard.
However, the thing that niggles me is the compromise between having a descent spoolup for driving and having to live with cruising at high boost.
What I've noticed is sustained high boost on cruise is both not needed and sky rockets the intake air temp. Its amazing how quick intake temps come down with a slow spool but then you loose driving response...
This mod I think will keep driving response with fast spool and enable intake temps to drop between duty cycles.

Sent from my Patrol using Tapatalk
If you want to test a far better arrangement leaving behind the limitations you just mentioned try this :
1/ PUT A NEEDLE BEHIND THE DAWES ( ie in serie with). MAKE THE DAWES TO OPEN MUCH MUCH EARLIER ( ie unscrew it almost to max, so that it opens as soon as some positive pressure is seen by the dawes ).

2/ SET THIS SECOND NEEDLE in such a way that you reduce the quantity of positive flow being injected into the vaccum hose of the actuator.

3/ DON'T FORGET to set again your first needle as you wish your spool-up to be.

This will make sure the vanes open continuously whilst RPM goes up, and wil get your VNT to work as it should, and not transformed into a stupid two-stage turbo.

Try and find the best arrangement to suit your driving and until you get a continuous rise of boost with RPMs.
Check the MAF value, as only FLOW matters, not boost !!! High pressure & little flow (MAF tension) means higgh back pressure and little efficiency. Smaller pressure and high MAF tension means high flow of air and fuel injected, and therefore POWER.

Your Patrol will run like never before. Believe me.

I have now thrown away my digibooster, and using my Patrol (2000) MAP to regulate the VNT with my own electronics, which allows me to get what I want when I want it.

But the three valves arrangement is the best and cheapest arrangement you can get. It mimics what an ECU would do quite accurately. And works beautifully once you have understood what you do with the valves.

Watch the limp modes though. If the flow of air you get is too high, MAF will be too high, and unless you control/reduce the MAF tension, you'll get limp modes if you push the flow too high. (note : the FLOW, not the boost).
 

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But the three valves arrangement is the best and cheapest arrangement you can get. It mimics what an ECU would do quite accurately. And works beautifully once you have understood what you do with the valves.
I understand using two needle valves as you have said but where is the third?
 

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nissan patrol
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If you want to test a far better arrangement leaving behind the limitations you just mentioned try this :
1/ PUT A NEEDLE BEHIND THE DAWES ( ie in serie with). MAKE THE DAWES TO OPEN MUCH MUCH EARLIER ( ie unscrew it almost to max, so that it opens as soon as some positive pressure is seen by the dawes ).

2/ SET THIS SECOND NEEDLE in such a way that you reduce the quantity of positive flow being injected into the vaccum hose of the actuator.

3/ DON'T FORGET to set again your first needle as you wish your spool-up to be.

This will make sure the vanes open continuously whilst RPM goes up, and wil get your VNT to work as it should, and not transformed into a stupid two-stage turbo.

Try and find the best arrangement to suit your driving and until you get a continuous rise of boost with RPMs.
Check the MAF value, as only FLOW matters, not boost !!! High pressure & little flow (MAF tension) means higgh back pressure and little efficiency. Smaller pressure and high MAF tension means high flow of air and fuel injected, and therefore POWER.

Your Patrol will run like never before. Believe me.

I have now thrown away my digibooster, and using my Patrol (2000) MAP to regulate the VNT with my own electronics, which allows me to get what I want when I want it.

But the three valves arrangement is the best and cheapest arrangement you can get. It mimics what an ECU would do quite accurately. And works beautifully once you have understood what you do with the valves.

Watch the limp modes though. If the flow of air you get is too high, MAF will be too high, and unless you control/reduce the MAF tension, you'll get limp modes if you push the flow too high. (note : the FLOW, not the boost).
You have just blown my mind with this one! Will have to go back and read again with a fresh head and cup of coffee!

What kind of boost do you achieve at 130kmh cruise with extra needle?

Sent from my Patrol using Tapatalk
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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359 Posts
Discussion Starter #5
You have just blown my mind with this one! Will have to go back and read again with a fresh head and cup of coffee!

What kind of boost do you achieve at 130kmh cruise with extra needle?

Sent from my Patrol using Tapatalk
what matters is MAF voltage, and therefore air flow.
I don’t understand why you are all paranoid with boost.
And by the way, that race to high boost is detrimental to engine performance.
only air flow plus fuel make the beast run.
With that arrangement you can set and tune as you wish.
 

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I don’t understand why you are all paranoid with boost.
And by the way, that race to high boost is detrimental to engine performance.
only air flow plus fuel make the beast run.
With that arrangement you can set and tune as you wish.
I'm not paranoid about boost. I like 20psi when I need max power. I don't like cruising at 130kmh with 17 psi (what I get with fairly conservative spoolup and dawes set to 20psi max) with my current single needle setup.

Sent from my Patrol using Tapatalk
 

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GUII ZD30DI Wgn
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what matters is MAF voltage, and therefore air flow.
I don’t understand why you are all paranoid with boost.
And by the way, that race to high boost is detrimental to engine performance.
only air flow plus fuel make the beast run.
With that arrangement you can set and tune as you wish.
Got to take you to task on the above Phil and also say that most of us are not paranoid about boost. If we go back quite a few years there was no extra Hp after 16psi, but as we got smarter and learned more about our ZD's we took that to 18psi, then took it to 22psi (the accepted max for the std turbo), all with std engines with ongoing, improving breathing mods. As we got even smarter, especially with the benefit of good remaps, we can take that higher but off course there are limits for std engines if you want longevity, mine is now set at 25psi but have tried 30psi, I would not stay there because I want longevity and 25psi is fine and I can assure you there is great Hp and Torque to be found there.

Having spent a lot of time on dynos over the last 10-12 years I can tell you a lot about where a ZD works well and what it can handle. I could go into a lot more detail on what I have discovered in the dozens and dozens of hours mine has spent on the dyno and the hundreds of hours in research.
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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359 Posts
Discussion Starter #8
I have no doubt about your knowledge and tests Ross.
I am attaching here a capture of MAP - MAF - RPM done this morning on my old lady to demonstrate what I am trying to explain with Boost (MAP) vs Air flow (MAF).

My Patrol is stock standard except EGR blocked, 3" stainless steel exhaust WITH catalyst AND muffler. Air intake standard. Standard Turbo. N75 vacsol controlled by my own sw and electronics. No remap. So controlled MAF / modified MAF value to stay below the known limp modes, and keeping the MAF voltage below the threshold until the next RPM level is reached (by sw and hw ).

You will see below how the true MAF voltage reaches 4.5V in second gear, a little bit above 3000RPM ( modified value sent to ECU is also visible in light blue), whilst the boost stays however below 1.2 bar, that is to say less than 18 psi.

So we can manage to get a big flow of air injected in the cylinder without going too high in pressure.

515636



Every one who has one dawes and one Needle has to accept a BIG compromise, as the vanes stay fully closed at the level set by the Needle, until the Dawes open. So yes, they build boost, but the airflow is small/poor, compared to what they would get with opening the vanes sooner. This is the reason why the result is always better with one dawes and the VACSOL, as the ECU starts opening the vanes much sooner.

Digibooster also opens the vanes a bit sooner, but cannot be precisely tuned, as it only has four settings for min aperture, and four for max aperture, even if the potentiometer allows a more precise setting.

Then the "laws" used to open the vanes in between, is unknown.
As I told, I am sure you managed to get the most out of it.

The One dawes - two needle gives you a very similar result to what a proper ECU would do, in a pneumatic way, and the beauty is that with the third 'degree of freedom' provide by the second needle', you can adapt the way your tubo work to your "style of driving" and your needs, with no drop in pressure when Revs go up, and a MAF voltage (ie airflow) always the highest .
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #9
I'm not paranoid about boost. I like 20psi when I need max power. I don't like cruising at 130kmh with 17 psi (what I get with fairly conservative spoolup and dawes set to 20psi max) with my current single needle setup.

Sent from my Patrol using Tapatalk
At the moment, I have around 12 psi on a flat motorway at 130km/h.
And I have 5-6 psi at 80km/h and 8-10 at 110km/h
But this is with my Electronics and Sw. I was getting similar values previously with the three valves.
With the three valves, there is no need to compromise on spool-up and boost. You can set as you wish, and your VNT turbo becomes again a VNT turbo. Not a two stage turbo as previously.
 

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GUII ZD30DI Wgn
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Mate I'm not going to complain about the torque and Hp I pull from my 'inefficient' system and there could be much more available but I don't need anymore.
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #12
t
How much power do you make phdv61?

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That is an excellent question. No idea.
I'll have to find somebody with a dyno I can trust in my region, even if originally, it was not my objective.
objective N01 was to get a properly controlled smooth and continuous rise in boost with TPS/REvs, maximising the MAF value.
objective N02 was to get a working turbo in altitude ( 2500m+).

I would have loved to get rid of the ECU-controlled MAF values, as, in the small areas where I have keep the MAF values under the threshold until the RPM reaches the right value, the ECU asks a bit less fuel to the IP than what it could.
But nevertheless, since I can drive up the hill to my home in 5th easily with little TPS, I assume it has nothing to do with what I had before. And same on the motorway.
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #13
Mate I'm not going to complain about the torque and Hp I pull from my 'inefficient' system and there could be much more available but I don't need anymore.
I did not say inefficient. I am sure you have reached the best arrangement ever for your Patrol configuration. And the REMAP does, I imagine, provide the right level of fueling vs MAF - RPM - TPS. Nobody does REMAPs here for this old ECU with soldered PROMs. So I had to find another way, to get the most out of my Patrol conf, with no Remap. Which I did.
 

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Mate I'm not going to complain about the torque and Hp I pull from my 'inefficient' system and there could be much more available but I don't need anymore.
Lololol. Neither am I Ross!!

"Boost pressure" is but a reference, not obsessing about it as others assert.
At the moment, I have around 12 psi on a flat motorway at 130km/h.
And I have 5-6 psi at 80km/h and 8-10 at 110km/h
But this is with my Electronics and Sw. I was getting similar values previously with the three valves.
With the three valves, there is no need to compromise on spool-up and boost. You can set as you wish, and your VNT turbo becomes again a VNT turbo. Not a two stage turbo as previously.
With much trial and error, you have emulated from my experience the factory boost curve.
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #15
Not very surprising, but with no overboost and no drop in boost linked to EGR blocked, nor too high a boost with my 3" exhaust. And lots of air in. Much more than before. I left it to the ECU to decide the volume of fuel which I assume it does using its maps which depend upon its reading of MAF ?
I have also unscrewed the limiting screw two turns, so I can close the vanes further in altitude, and get the turbo to start pushing air in, even at -300mbar 'boost pressure' ( 700mbar absolute). I don't know if you have ever tried to drive your Patrol at this altitude, but man, it is (was) a disaster.
 

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I have also unscrewed the limiting screw two turns, so I can close the vanes further in altitude, and get the turbo to start pushing air in, even at -300mbar 'boost pressure' ( 700mbar absolute). I don't know if you have ever tried to drive your Patrol at this altitude, but man, it is (was) a disaster.
CRD, Also regularly drive from 600 to 1300/1500m this increased altitude did impact on performance ie: increased pressure drop across cooler alone_1.5 psi to 3psi (remap/stock TIG IC/induction pipework/manual boost control), but with improved induction (cooler/ducting and running Tillix inconjunction with VNT vac sol) my performance is not adversely impacted any where as much as was using stock induction set up.

One concern I have is that my tune was done at near sea level, do understand that ECU compensates for changes in barometric pressure and another reason why I prefer for ECU to control VNT operation. Guess this is a correct assumption.

Interested: When you
unscrewed the limiting screw two turns
, on vane limit stop screw what was the change in vacuum (increase) to raised actuator rod for lever to hit stop ?
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #18
CRD, Also regularly drive from 600 to 1300/1500m this increased altitude did impact on performance ie: increased pressure drop across cooler alone_1.5 psi to 3psi (remap/stock TIG IC/induction pipework/manual boost control), but with improved induction (cooler/ducting and running Tillix inconjunction with VNT vac sol) my performance is not adversely impacted any where as much as was using stock induction set up.

One concern I have is that my tune was done at near sea level, do understand that ECU compensates for changes in barometric pressure and another reason why I prefer for ECU to control VNT operation. Guess this is a correct assumption.

Interested: When you , on vane limit stop screw what was the change in vacuum (increase) to raised actuator rod for lever to hit stop ?
Hi,

What gave me the idea to unscrew to improve in altitude was the fact ( and you can check it with your ECUtalk tracking the VACSOL pwm value sent by the ECU), that the pwm value sent to the Vacsol by the ECU varies with Altitude at idle (max vanes closure) BUT the limiting screw prevents the rod to close the vanes further.
ie : 55.9% applied at sea level, idle. 60.9% at 1200m. but at 55.9%, the lever has already hit the limiting screw.

with my Patrol configuration (EGR blocked - 3" stainless steel exhaust), I have set 53.9% idle at sea level ( the setting to get the spool-up I wanted), and 57.5% at 3000m which means a further closure of 1.2% pwm per 1000m.

1/ You CANNOT unscrew with the ECU stock software as it is. It won't work, as the Patrol maps are not tuned for this. However, in altitude, the MAF value goes much lower than at the sea level. May be a remap, providing proper values are put facing these low values are correct, would work. no idea.

2/ you need an absolute MAP sensor ( like the stock one ) to know the absolute pressure, and the pressure sensors 0-30psi which work for pressures > 0psi are useless, such as the one which goes with Digibooster for example.

3/ at 1000m, the stock PATROL remains drivable. Not true at altitudes exceeding 2000m unless you stay all the time above 2000RPM, which you cant' do in very rocky slopes ,and/or when you have to turn. It is like you had no turbo at all.

The only way to achieve a proper result is to manage the vanes aperture/closure very precisely. And this is the reason why i embarked on this development project with hw and sw.
 

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NISSAN PATROL Y61 3.0 Di (ZD30) 09/2000
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Discussion Starter #19
Did you notice any difference in EGTs with the 3 valve set up?
short answer : no idea.

long one : In my country, out of 6000 PATROLS, almost nobody checks EGT. What we are paranoid about is boost value / MAF - Air flow, injectors preventive replacement every 100 000km (1600bar pressure - if they go wrong, they crack the pistons) as well as glow plugs. And no water in fuel, detrimental to IP and injectors. and we also add 2 stroke oil in the fuel to lubricate the IP. That's it. We don't tow as heavy trawlers as you do, and we globally do not have your very high temperatures either.
 

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Discussion Starter #20
last but not least, I don"t see any reason why, with having the VNT turbo working as it should ( ie VARIABLE nose turbo), the EGTs would go up. What is clear, is that if you open the vanes sooner, you'll get a bigger flow of air ( a diesel works with an excess of air), and the ECU will get to the IP to inject more fuel, but the AFR should be as decided bu the Nissans Engineer during thir engineering. What is true, is that you'll get more power than if you use only one dawes and one needle.

An arrangement with ECU and dawes or Needle will suppress the overboost when your EGR is blocked, but will not compensate for the "lows" linked to the absence of EGR opening. One dawes and two needle, when set-up properly gives you a very similar result to what an ECU would do, if it had been designed to work with no EGR.

And you can have a proper spool-up and rise with RPMs to the max pressure you wish, wirth a continuous opening of the vanes a VNT turbo offers. And all that with no hole and no peak. It will not fix the altitude issue though.
 
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