Thread: TDV8 Egr map out and remap 2010 TDV8

Ok so I've finally bit the bullet and ordered the BAS remap for my 3.6 TDV8 vogue.
After paying online I had the map ready for installation all within an hour.
Very speedy service by pete.
So it's very late now and I will install it in the morning.
Will keep you posted as to how it goes.
I've purchased it for better low down power and less sluggishness. Not for speed or driving like a maniac.

I loaded the remap this morning and also reset the auto transmission at the same time as requested by Pete.
The car initially seems to have a little more pull just of idle and quite a bit more in the midrange.
I'll test it more over the coming weeks and report back.

There is a good argument for a catch can. The problem with EGR is that the soot mixes with the oil from the crank case vent. A catch can is installed inline to remove the oil, resulting in only EGR soot being routed to the inlet. Without the oil, the soot is less likely to form a think gunk.

There are some claiming that an open EGR increases engine/exhaust temps, from my research and testing this is incorrect.

Research I've been doing for the VAG side of my garage has told a different side of this story. There is a case for EGR to remain in the later engines as the introduction of exhaust gas into the inlet is primarily to reduce NOx - however this is achieved by reducing the % of fresh air the engine consumes which reduces combustion temps because the oxygen level is lower, this is despite sucking in warm exhaust gas (it is warm not hot as it goes through the EGR cooler). We have confirmed this theory in the 2.0tdi VWs and what it shows is a significant increase in average and max EGTs (hitting 850degC) when the EGR is blocked off, reportedly enough to cause turbo failure. It is to the point that no tuners will tune out the EGR in the later VAG diesels (they are still doing it for the older 1.9 which is a very under stressed engine, down on power and torque by some 45% compared to the 170 2.0). Using what I can only describe as the best diagnostic system I've come across, we can see when the EGR opens and the result is an immediate reduction in EGT.

The increase in combustion temp is seen as such a risk that VAG engineers have the EGR default to open if it is unplugged - tested and confirmed.

The EGR has such an effect on combustion temps that it is also used for active maintenance of Diesel Particulate Filters (DPF). Now DPF is not of interest to the L322 community as we are lucky enough not to have them, however it does demonstrate how the EGR is used to regulate combustion temps. The follow points are copied from the VW tech training on DPF and descried what the engine ECU does to increase EGTs to 500-650degC during idle!!! Unfortunately the diagrams don't want to copy.
● exhaust gas recirculation is switched off to raise the combustion temperature,
● an extended injection period is initiated, after a period of main injection with reduced quantity at 35deg crankshaft angle after TDC, in order to increase the exhaust gas temperature,
● the supply of intake air is regulated by an electric throttle valve and
● the charge air pressure is adapted so that the torque during regeneration does not change noticeably by the driver.

So, it closes EGR, and by over fuelling and blocking air it creates a super-rich mix. It actually does a pretty good job at hiding the process from the driver, only thing I notice is that it is holding each gear a bit longer, and if you switch off when it's halfway done you can smell the heat, and the fans run for a good 10 minutes to cool the engine bay (DPF is just in front of the firewall up quite high) Back on track - the important point for this discussion is that the first thing it does is close (block) the EGR to increase combustion temps. And from what I can see during road testing, it is nearly the only time the EGR is fully closed.

All my testing has been conducted on VAG vehicles, and has achieved the exact same results as the tests carried out by the local go faster shop. Given that our RRs are running bosch/siemans engine management which is the same as what VAG run, I can't see that they would be any different.

Back to my original point, sorry got a bit side tracked. Installing a good catch can like the Provent 200 or the 43Draft Designs unit would remove the oil from the inlet, greatly reducing the build-up of crud. BTW, don't bother with a cheap ebay can, they don't vaporise enough oil.

Those of us with TD6 have removed the EGR, now there is just oil, similar result - without soot, the oil shouldn't create gunk. However, on a side note after the install of the cyclonic oil separator the volume of oil from the CC is making me think about catching it...

Thanks for all the detail on EGR Harlie. BAS hasn't removed any egr on my TDV8 remap. They have left it alone. But what your saying makes sense. My last TD5 had the rocker cover vented to atmosphere....dde31dde33 So the oil vapor never went into the intake prior to the turbo and egr was blocked off. I think I'll leave the egr alone on this car and try and do regular cleaning of it (every year) It would be good to vent the rocker cover fumes to a provent but I have no idea how or where his would fit on my motor. There's pipes and things going everywhere.

Here's the crankcase ventilation diagram from the workshop manual p 1604.



image-3996955540.jpg

Here's the EGR diagram.


image-3143889615.jpg

Are they really small jpg or am I doing something wrong?

Originally Posted by harlie

So, it closes EGR, and by over fuelling and blocking air it creates a super-rich mix.

LR workshop manuals describe the same process but the reason for closing the EGR valve is to prevent fuel and air-rich exhaust gases being returned to the combustion chamber so that those exhaust gases get to and burn in the catalytic converter to generate enough heat to burn out the DPF. The cats are run at their maximum possible temperature and to get that hot the exhaust gases need to have fuel and oxygen to burn. The after-burning starts in the exhaust manifold due to fuel injected too late to combust properly which is why the EGTs, measured at the manifold, get so high.

I suspect that turners are no longer closing EGR valves because of the recently introduced large penalties in Europe for interfering with emissions systems.