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Gally
A mate who also has a D4 3.0 sent me this link yesterday.
It seems the poms are doubting your product.
Have a read and let us know your response.
Bare in mind its important for us who are thinking of taking the plunge.
Thanks
Andrew
DISCO3.CO.UK - View topic - EGR Emulators D3 and D4
IMO there's nothing in the Disco3 thread of any value.
From closing the EGR valve in my previous TD5 where an improvement in fuel economy was achieved I would also expect an improvement in these engines. More torque at low revs improves fuel economy when the engine is only lightly loaded. The 8% was on a 3.6 TDV8 which would have even more potential for reduced fuel consumption than a 3.0.
EGR valves are closed during DPF regen to ensure maximum exhaust heat gets to the catalytic converter.
2 MAFs on the 3.0 (& 4.4) are not an issue because if the 2nd MAF is in use then the engine would be doing sufficient work to be well past the threshold for having EGR valves closed. Modifying the primary MAF values would be all that is needed.
Driving harder in Oz wont show-up any problems with having EGR valves closed as they would be closed anyway. However driving harder has the potential to show-up inappropriate MAF value manipulation but presumably that manipulation wont occur when the EGR valves are meant to be closed anyway.
Graeme you have hit the nail on the head. I was just in the process of replying.
(EGR valves are closed during DPF regen to ensure maximum exhaust heat gets to the catalytic converter)
They definitely are closed and I will put my finding in a moment
Quote:
Originally Posted by LandyAndy
Thanks LandyAndy,
Hey that's not fair is it. Robbie thinks I cant count.:p
As Graeme has pointed out, On the D4 3.0, one Maf measures air to the Primary turbo and the other, air to the secondary turbo.
The Air is blended when the Compressor shut-off and recirculation valve allows it but I found that only the primary Maf reading needed to be altered to achieve a fault free result.
Altering the Maf reading is not detrimental to fueling at all. It happens every time the EGR valves open.
The Engine gets air the Maf's don't know about. That's what the MAP and H2O sensors look after.
Whether you do this internally as a patch or externally as an emulator, is irrelevent. The results are the same.
When the EGR valves are emulated there is a very small window were the Maf reading of the primary turbo is lowered and it is a very small amount. This mimics the effect of the EGR valves. The engine intake is still drawing in the air quantity it needs for a correct burn.
DPF Regen,
I had the benefit of 2 customers D4's with blocked and nearly blocked DPF's which made for a good few days of testing.
I did many tests on both Passive and Active regeneration modes.
Passive didn't use any Engine management changes at all but Active was a different story.
When the differential pressure sensor dictated that DPF needed cleaning the Engine management or the DPF fuel managent module , as Land Rover calls it, raised the combustion and Exhaust temperatures by adding extra fuel in the form of post injections.
This could be seen on the Pico scope measuring the injectors and referencing it against the crank sensor.
The DPF temperature raised to 520 Deg C for approximately 5 minutes. The EGR's were closed the whole time. When I checked the manual it stated "During active regeneration, the EGR operation is disabled -except for overrun conditions - and the closed-loop activation of the turbocharger boost controller is calculated. The air management module controls the air in the intake manifold to a predetermined level of pressure and temperature. This control is required to achieve the correct in-cylinder conditions for stable and robust combustion of the post injected fuel."
Which was exactly what I was seeing. So all good there.
After nearly 5 mins the fuel injections increased in duration and the temperature went up again to 638 Deg C, EGR's still closed, I noticed that the IMT (Inlet manifold tuning valve), was moving when the DPF temperature was at its highest. I realised that this was controlling the amount of air into the engine to maintain the correct regen temperatures. This is why I have always left the butterfly in.
The EGR valves had no effect on DPF regen what so ever except whilst driving in over run where it trys to reduce NOx
With the EGR's disabled the Regen worked in exactly the same way.
Regen temps were altered by the Engine Management moving the IMT valve and changing the duration of the post fuel injections.
Sorry for the long post but i hope this explains things a little better. :D
Reading the Disco3 post I see someone has claimed that any improvement in fuel economy can only be true if the EGRs were already dodgy. Well if my EGRs were dodgy in operation then I am doubly glad I fitted the emulators rather than have to strip and clean or replace the EGRs, a job I cant do myself so would have to have paid to have done, the emulators being a cheaper and better option IMHO. The main thing for me if my EGRs were dodgy is that the EGR's were fully closing and not staying part way open - so that fitting the emulators results in fully closed EGRs. Mark provided me with info on how to check this and yes they were fully closed and now are permanently so. The bonus being no more dirty air into the inlet. Oh - lots of kms now and car is running faultlessly.Quote:
Originally Posted by LandyAndy
Great post Gally.
Not only do you explain what the system is doing but having test results showing your gear is compatible with the engine.
Thanks
Andrew
Just ordered a set of emulators today if they work as good as my blanking plates on my old 05 D3 I will be very happy. I found that in the morning the vehicle took longer to get to operating temperature. Didnt notice any difference while getting up to temp as in performance .I did over 60 thou with them fitted my fuel consumption greatly improved also as did the performance cant wait to get the emulators.
Cheers
The 3.6 TDV8 has two MAFs too though, right?Quote:
Originally Posted by Graeme
Yes, but my understanding is that the MAF signals on these true twin turbo engines don't have to be adjusted, unlike the later 3.0 and 4.4 sequential turbos where more cross-checking of airflow with MAP sensor data occurs. More can go wrong with airflow on the sequential turbo engines due to the use of an inlet isolation valve so more checking is appropriate, as well as more detailed checking that EGR is operating as expected.
Thinking of putting a pair of these on my brand new Territory engine, so that it never gunks up. Am I correct in understanding that the EGR valves are closed fully when the vehicle is turned off, so there is no need for a physical blanking plate in the EGR pipe, assuming that the emulators retain the fully closed position? The input cable to the emulator is disconnected from the valve and plugged into the emulator, so there is no way that the valve can open as it has no power?