An egr block is a physical barrier to stop or reduce exhaust gasses entering the throttle body.
A catch can is to condense the oil vapor from the crankcase vent to minimize the condensed oil in the intake system (turbo/intercooler/throttle body)
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An egr block is a physical barrier to stop or reduce exhaust gasses entering the throttle body.
A catch can is to condense the oil vapor from the crankcase vent to minimize the condensed oil in the intake system (turbo/intercooler/throttle body)
G’day mate welcome aboardQuote:
Originally Posted by PerthGuy
Two totally different things mate.Quote:
Originally Posted by PerthGuy
The EGR block. Blocks the exhaust gases that are recirculated back into the air intake via the EGR valve. A catch can, filters( filters as in cleans the gases of the oil) the crank case vapours that are recirculated from the rocker cover and back into the air intake.
Two totally different things.
I have had a dawes and needle setup on mine for about two years now, with no ill effects. The ecu does a good job on an unmodifed car.
Hi all, thanks for your responses and apologies for the delay in coming back here.
are the air paths totally different. ie should you do one or the other, or both? the catch can cleans the air that goes in and the EGR block stops it from getting into the air intake completely.
If worried about the air intake, would the EGR block be sufficient. Maybe the catch can stops (reduces) particulate deposits elsewhere in the engine?
Just bought a 2015 GU ST, 50,000km and am loving the car so far. So much potential and certainly different from the prado!
when the car is on boost and you then take your foot off the throttle , the pressure blow back in the air intake carries engine blowby gasses back past the MAF sensor , after a while this builds up on the MAF sensor and causes it to give false readings . A catchcan greatly cleans up the blowby gasses which in turn keeps the MAF sensor cleaner longer . although it is still advisable to occasionable clean the MAF sensor with MAF sensor cleaner spray occasionally ( i do mine when i do oil changes ) . if the egr is not blocked the catch can does go someway towards helping keep the inlet manifold and valve intake ports clean , as the blowby gasses combine with the egr gasses to stick and clog them up .
if you block the egr it would stop the crud buildup occurring in the first place , and most people would get better fuel economy and more power although you may need to look at a dawse and needle valve arrangement to help control the turbo , which has benifits of allowing higher boost ( more Power ) and better driveability ( more power at lower RPMs )
Ok Thankyou. That’s kind of what I was guessing. Block it off then don’t need a catch can.
Do you have to do the Dawes and needle valve if you have blocked the EGR?
Thanks again for helping a newbie out
Boost is not what is needed by your engine.
Only airflow matters ( MAF voltage represents an estimate of the quantity of air pushed by the turbo inside admission and your cylinders.
It is a common but wrong belief that all you need is boost.
Take a garden hose. Close it. open the tap. You build pressure in, but you get no flow.
Make a very little hole in it. You'll get pressurized water, but no flow/quantity of water pouring.
Now take you dawes. it blocks any flow until it opens. As a result, the vanes are closed, the turbo spins, but exhaust gaz can't exit the cylinders fast enough. All you do is build-up back pressure, and therefore boost, but very little flow.
Little quantity of air, small MAF voltage seen by the ECU. The ECU requests a small quantity of fuel to your IP. And you get little torque/power down low.
The way the vanes of a VNT MUST be managed ( and this is the way the ECU manages the VNT for a full STOCK configuration is as follows :
keep the vanes closed until the exhaust turbine spins fast enough. At 3psi, starts opening the vanes as boost is building up, until mid-aperture is reached. This vanes position ( mid-aperture / mid-closure) is the position at which the turbo provides its best efficiency !!
Stay in that position / open very slightly vanes as boost continues to build-up until you get close to max boost, then open vanes more rapidly to keep max boost under control.
Good luck with valves. As a minimum, set 3 ( yes THREE : one dawes TWO needles ) valves as follows :
get the dawes to open at 3-4 psi. put a needle behind the dawes to regulate the positive flow which is going to open the vanes.
The outstanding issue is that you will not be able to stop the vanes from opening at mid aperture. Only a proper electronic control can provide the exact positioning of vanes at all times, depending upon your Patrol configuration.
So you will have to compromise, and will never be able to get the right cruise boost that you wish to have, at 80 or at 110 km/h.
Only one position of the vanes at all loads/Revs provides the maximum airflow (and maximum power). I called this the 'turbo map'.
I have spent two years studying an analysing in detail what my 2000 Patrol was doing, and why. And found the solution to accomodate properly my EGR being blocked and my 3" exhaust (less back-pressure ), with the best spool-up, torque down low and power.
Only the MAF value matters. Believe me.
As soon as you touch anything to your stock Patrol, your ECM is lost and can't manage. There are many work-arounds, but none is perfect, and some worst than others (one dawes one needle). Sorry to be so blunt, but I spent so much time trying to understand it all.
I wished someone had explained all this to me 2 years ago when I was scratching my head, and bumping it against the wall.
Soooo what have you done?Quote:
Originally Posted by phdv61
you don't have to have any of them, they are all there to help improve your engine performance and longevity, to some extent. in my opinion, you need a catch and block the EGR, on any diesel engine. The EGR simply blocks up your intake system with soot and mixed with oily crankcase vapours from not having a catch can will make your intake block up like cholesterol...Quote:
Originally Posted by PerthGuy
Not sure about your first comment. When I had my ZD di, there was a massive difference in performance from 15psi of max boost, to what I ended up setting it at to 25psi of max boost with 18 psi cruise boost. The main issue was getting around the 16psi boost limit the ECU had, once I got rid of that I could do anything I wanted and the not worry about limp mode.Quote:
Originally Posted by phdv61
Don't get me wrong.
I am not saying you do not need to have more boost to get more air in.
But boost is not all. What you need is to maximize the quantity of air getting in your cylinder, as measured by the MAF voltage.
There is not limitation at 16 psi boost on the Di. The MAP sensor is not used.
I can get 20 psi if I wish, although, beyond 18 psi, the increase of air you get is little are you are getting beyond the efficiency zone of the 2052 garett turbo.
Getting a lot of boost down low is only creating backpressure, and little air is coming in. In other terms, you reduce the power/torque you can get from this engine. If you let it 'breathe' properly, it becomes another "animal".
To move the 2.5T, you need torque down low, which you don't get if you keep the vanes closed too long, and beyond what is needed to get the initial turbine spin. You need to free the exhaust gaz, or you build too much back pressure preventing the cylinders to get rid of the exhaust gaz, making room for more fresh air + fuel. And you have reduced torque and ... driving pleasure.
On my old Di the boost limit was 16psi, yes not via the MAP sensor as you say, just thats when the stupid thing would just a have hissy fit and go into limp mode, at 16psi, or 14psi if I wound in the needle valve for faster spool up. After changing out the MAF housing for a high flow housing, no limp, no hissy fits, nothing, I wound the boost out to 30psi and still nothing. Drove great.
This is a non-sense mate.Quote:
Originally Posted by mudski
reducing the MAF voltage makes the ECM believe there is less air than real. So, the ECM requests less fuel to the pump.
Pushing boost, when reducing the MAF voltage, results in increasing the AFR by reducing the fuel injection.
The only way to get the most of our 3.0 motor is to control the MAF value at all times by using the RPM signal, and manage the turbo vanes directly to maximize the MAF value. I explained all this in details on a Patrol site, and many abandonned dawes+needle for dawes + 2 needles, and now the magic box. That one makes an unbelievable difference.
I am just sharing here the result of the 18 months I spent full time of deep analysis and development to overcome once for all the limits of my own Patrol owned for 21 years now.
The problem with beliefs which have been going on for so long, is that it is hard to believe they were just wrong. I have been misled myself, so I know what it is ! I have been running my home made electronic VNT controller including a LIMP avoidance function, and my old lady became a young girl, climbing like never, to the top of the highest mountains I have around.
Crikey, if you Two Legends can agree I’m for sure reconsidering going back to a 3.0L [emoji41][emoji106][emoji106]
By far the zippiest Patrol we’ve ever family owned, unfortunately had to get rid of it humanely clutch hauling Nags in our hills and had to revert back to a sluggish TD42T, did I mention SLUG [emoji222][emoji23][emoji106][emoji106]
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Haha! I'll agree to disagree. I only supplied maybe 5000 of these kits worldwide and fitted maybe a couple of hundred during my time with the shop. But yes the ZD is quite zippy. Easier to drive than the TD in the burbs, but thats all its got going for it.Quote:
Originally Posted by MB
Making the ECU believe there is less air coming through by enlarging the inlet, or by simply adding one or two schottky diode in serie (costs only 10 cents each) with the MAF signal to reduce it by 0.15V or 0.30V have the same dual effect :
1/ it suppresses the limp modes as the MAF voltage is reduced
2/ it also reduces the fueling and therefore the power/torque as the ECM makes use of the MAF voltage to request the correct amount of fuel per stroke to the IP. Believing otherwise is just wrong. Just put a voltmeter on your MAF signal wire, and you will just see with your own eyes what I am saying here.
And if you consider the MAF 'characteristic response' in volts to quantity of air in g/s , which is a 'log' curve (available on the net), you will see that missing 0.3V ( ie measuring 3.7V instead of 4V) makes the ECM believe there is 30% less air (!!) and therefore the ECM will ask 30% less fuel to the IP.
Unless you go for a remap which increases the well known limp thereshold values, to suppress them, the alternative is to use the RPM signal to clamp the voltage just below the limp threshold(s) until the RPM goes above the associated RPM limit, after a delay of around 2s. Only electronics and software allows all these "subtilities".
With the magic box VNT, and by managing the garett vanes properly, I can get more than 3.65V below 2000RPM ( limp at 3.55 ), and well above 3.88V below 2500RPM, 3.98V below 3000... etc. Never any limp, immediate spool, and max power and torque out of my engine at all Revs.
Historically, people with limp used to screw the limiting screw to decrease the initial spool-up (same effect as adding a needle), but at the expense of getting a 'sluggish' Patrol. Some went on modifying the MAF enclosure (just to reduce MAF voltage which you can get with a simple non-expensive diode).
People who have now moved to Magic box in several countries do get a full control of their turbo 'map', maximize the airflow at all Revs (and therefore the Torque and power) with boost under control, no peaks - no holes.