some ecu's they can program the EGR side of things so it only turns on at some never achievable setting. however afaik no one has reprogrammed these ecu's.

you can't trick the ecu otherwise for eg it will run on the cold map constantly.
fortunatly these ecu's are not full OBD2 so they don't monitor the egr system as tightly as say a petrol motor. hence the ecu doesn't really know the egr is not working. it only checks the valve itself. as long as the coils don't blow it thinks its all fine. (which i think is the cause of some of the problems these get. ecu doesn't know if valve is stuck.)

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D22 ZD30 egr+butterfly mod, 2" lift extra leaf springs, enk-tek dump pipe, 2.5" exhaust.
single cab workhorse, to muddy to clean

A bit of both actually. My aim when doing the porting was to keep the ports and runners as small as possible while sorting out obvious deficiencies in shaping and casting marks.

The only suggestive thing about pulse tuning in the ZD30 for me is that it does look as though it has different length runners for each side of the swirl valve. But as I wrote somewhere previously, I found the system on my RB20 to be pretty ineffective in producing a performance benefit at low rpm and a detriment at high rpm due to all the extra hardware in the air flow becoming a restriction. There is also more to it than just pulse tuning. At low rpm the gas velocity would be more important and that is exactly where dual inlet tract setus are in theory better.


It is a pity that no one would seem to have cracked the mapping of these ECU's, if they did you would alter the variable as you said, just disable EGR operation for anything under something like 110 degrees coolant temp so it just never became active.

i just did the egr+butterfly mod today.
i noticed a difference in the low range rpm but not in the higher rpms, also the wind down of the engine is that normal? i have to say that the car runs a lot smoother then before. it doesn't fills like im driving a tractor anymore.

normal. at high rpm your basically at full noise and EGR is off. EGR is generally on the most at lower rpm and low throttle (ie cruise) which is why you notice the difference at those revs.

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D22 ZD30 egr+butterfly mod, 2" lift extra leaf springs, enk-tek dump pipe, 2.5" exhaust.
single cab workhorse, to muddy to clean

tweak'e what about the wind down in the engine that i can hear when i am decelerating? i dont know if its the turbo that i can hear more. if so is that normal

i can't remember if mine made much of a difference.
the turbo is spinning faster so you will notice some more turbo noise especially when you go off throttle.

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D22 ZD30 egr+butterfly mod, 2" lift extra leaf springs, enk-tek dump pipe, 2.5" exhaust.
single cab workhorse, to muddy to clean

ok thank for help tweak'e. ill keep an eye on the fuel too and ill let you know how i go

I did the EGR mod today. Was kinda daunting to start with but i gotta say it made a big difference. Feels alot smoother now, boosts better and the engine actually sounds quieter. Once before it had a slight tapping when cruising, now thats basically gone. Big thanks to everyone who provided pics and instructions on how to do it. Was a huge help..

i used that stuff they have been making gaskets out of forever, its got metal weaved through some type of rubbery stuff. you can cut it with tin snips or even good scissors, lasts forever. just had some sitting around in the shed

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D22 Nissan Navara STR ZD30

As requested by tweake, i reported in another thread about my fuel economy before and after egr mod. A couple of notes though as my result may be different for a number of reasons, but my reasoning suggest the egr mod was the main player in the economy figures. About a year ago my turbo crapped out and I rebuilt my engine. Before this happened, I always got around the 10L/100km. It was a bit better in the city and a bit worse on the highway, I think this has to do with roof racks. But lets say avg 10L/100km. Then turbo dies, rebuild motor with all new bits, new injectors, new turbo, rebuild injection pump and block egr. Ran the car for a while and it was getting around the 12-13L /100km, I was told this may have to do with increased friction on all internal parts so wasting a bit of fuel, should get better with age. Not so, fuel economy stayed the same for 15,000km's. Then put the intercooler on a few weeks back, economy back down to just over 10l/100km. Now in my case, because so many changes were made at the same time, I cannot ultimately conclude the egr is to blame, but with my reasoning that the egr is an extra fuel source which was being used, but is now going out the exhaust pipe. I guess the only way to test this is to unblock the egr, not likely going to happen as I have now got an engine that has never had the egr put through it and I don't want all that carbon coating every internal component.