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[Marks DTM Calib]

I can't help wonder why manufacturers appear to struggle with the basic tune?

Chipping remapping or retuning a diesel appears to see good improvements on all front's afaict. Better power output is the first obvious one. But also better economy as well, with less smoke.
My understanding is the black smoke is caused by Unburnt fuel, so what's the difficulty about tuning a diesel that means its easier to fit a Dpf than tune the engine to give less smoke or a cleaner burn?

I'm missing something clearly. No pun intended.


Apart from waisting fuel, why can't the Dpf set its own throttle at 2000rpm while the car is on the drive? Do its regen, then let the driver in his way?
Edit, actually, that wouldn't be very fool proof.

Manufacturers have considerably more constraints than the tuning companies, not least they have to meet the full EC specs which gives the compromised tunes where as once built and type approved, an MOT smoke test is the only real check the engine will ever see from that point on (and the new visual inspection of emmission control components).

The economy gains on modern diesels are some what over stated, tuning boxes as an example may appear form the TC (trip computer) to give better economy but any improvements are negligable (the tuning boxes modify the rail pressure signal to the ECU making it think it needs a longer duration of injection so more fuel is dumped in but, the TC uses the duration v pressure to calculate economy so the TC figures become over inflated).

Clearly a full remap which also increases boost can give big gains and on some engines simply increasing fueling can do similar because the engines run with a large percentage of excess air which improves throttle response (no need to spool the turbo up fast when acceleration demand is input).

A big issue on a number of vehilces with the tuning is the drive train, many of the boxes fited to the pwoer plants are run close to the max torque so a very negative impact can be seen here! (as an example, the M32 used on many of the 1.9 CDTi's needs an oil cooler fitting to make it last with increased torque as it runs dam hot in standard tune and the oil degrades quickly resulting in bearing failure).

Easiest way to spot a regen is to watch the fuel consumption, it drops by circa 20 mpg and often there is a drone that can be heard from the rear silencer (dependent on body shape etc with obviously an estate car being less sound deadened in that area than say a saloon or hatch), they are often more sprightly to with a snappier throttle response (althoguh this is only noticed if you apply throttle, when cruising or on cruise control it can easily go unspotted)

[05omegav6]

Not sure about the 3.0 CDTi Al regarding tech 2 disable, it can certainly be deleted by other means though.

That is reassuring 

My typical day involves a twenty minute, eleven mile commute, quite often in traffic, followed by 10-20 urban journeys of two or three miles, again all in traffic. If I do go any further than the outskirts of Horsham, then I do see dual carriageways, but littered with roundabouts and traffic lights. I suspect that the ecu would start a regen cycle after a minute of dual carriageway, only for me to need to stop at a roundabout 

I have spent time driving a brand new hybrid 7.5t, which killed its dpf in about 6 weeks, inspite of regular motorway work

[Marks DTM Calib]

Not sure about the 3.0 CDTi Al regarding tech 2 disable, it can certainly be deleted by other means though.

That is reassuring 

My typical day involves a twenty minute, eleven mile commute, quite often in traffic, followed by 10-20 urban journeys of two or three miles, again all in traffic. If I do go any further than the outskirts of Horsham, then I do see dual carriageways, but littered with roundabouts and traffic lights. I suspect that the ecu would start a regen cycle after a minute of dual carriageway, only for me to need to stop at a roundabout 

I have spent time driving a brand new hybrid 7.5t, which killed its dpf in about 6 weeks, inspite of regular motorway work

Its useful to be aware that there are times that the regen will be inhibited such as when a fault is present or if the engine is not upto temperature (so a failed thermostat will stop it and may not give a fault light.....).

Of course a condition where combustion is compromised and the exhaust smoke increases will also shorten the time requried between regenerations such as a partialy stuck open EGR valve or failing/leaky/fouled injectors.

[I_want_an_Omega]

I can't help wonder why manufacturers appear to struggle with the basic tune?

Chipping remapping or retuning a diesel appears to see good improvements on all front's afaict. Better power output is the first obvious one. But also better economy as well, with less smoke.
My understanding is the black smoke is caused by Unburnt fuel, so what's the difficulty about tuning a diesel that means its easier to fit a Dpf than tune the engine to give less smoke or a cleaner burn?

I'm missing something clearly. No pun intended.


Apart from waisting fuel, why can't the Dpf set its own throttle at 2000rpm while the car is on the drive? Do its regen, then let the driver in his way?
Edit, actually, that wouldn't be very fool proof.

Manufacturers have considerably more constraints than the tuning companies, not least they have to meet the full EC specs which gives the compromised tunes where as once built and type approved, an MOT smoke test is the only real check the engine will ever see from that point on (and the new visual inspection of emmission control components).

The economy gains on modern diesels are some what over stated, tuning boxes as an example may appear form the TC (trip computer) to give better economy but any improvements are negligable (the tuning boxes modify the rail pressure signal to the ECU making it think it needs a longer duration of injection so more fuel is dumped in but, the TC uses the duration v pressure to calculate economy so the TC figures become over inflated).

Clearly a full remap which also increases boost can give big gains and on some engines simply increasing fueling can do similar because the engines run with a large percentage of excess air which improves throttle response (no need to spool the turbo up fast when acceleration demand is input).

A big issue on a number of vehilces with the tuning is the drive train, many of the boxes fited to the pwoer plants are run close to the max torque so a very negative impact can be seen here! (as an example, the M32 used on many of the 1.9 CDTi's needs an oil cooler fitting to make it last with increased torque as it runs dam hot in standard tune and the oil degrades quickly resulting in bearing failure).

Easiest way to spot a regen is to watch the fuel consumption, it drops by circa 20 mpg and often there is a drone that can be heard from the rear silencer (dependent on body shape etc with obviously an estate car being less sound deadened in that area than say a saloon or hatch), they are often more sprightly to with a snappier throttle response (althoguh this is only noticed if you apply throttle, when cruising or on cruise control it can easily go unspotted)

Ok, so if you set off on a journey and are soon on a fast road doing a constant 65 or 70, listening to the radio in a quiet car then it's possible that you will miss it unless you are constantly watching the instantaneous MPG. As I said, I failed to notice anything in 2 years and 60k miles so it must be a fairly subdued event ..........

[Sir Tigger KC]

I've been wondering about some sort of DIY fix for these DPF filters along the lines of cleaning them out when they get clogged. 

When I was a yoof and was whizzing about on a 2 stroke 50cc 'bumblebee', we were always whipping out the baffles from the exhaust to burn off the oily crud that accumulated with a blowtorch, bit of a wash in petrol and a scrub with a wire brush to maintain that blistering performance!!   

So how about doing something similar with a clogged DPF filter?    Could it be washed out with petrol or similar solvent?  Maybe heated up somehow to burn the crud out? 

[al brown]

I am sure my naff code reader will activate a dpf regeneration cycle with the car on the drive. On brothers signum anyway. We didn't run it as his is fine right now, we were turning off the passenger seat belt warning and I remember seeing the option for the dpf. It had plenty warnings about the noise and heat generated. As far as I know the ECU will initiate a regeneration when needed as long as the car is in the right condition, as others have said, up to temp, no faults etc but I am sure the  problem comes from the fact most need to have the revs above 2000, which many modern diesels only achieve if you cruise quite quickly.
Al

[Nick W]

It's not unusual for a light to come on whilst the DPF is regenerating. Many people see this as a 'management fault' and have been programmed to turn the the car off as soon as they see it. This is, unfortunately, precisely the opposite of what is needed.
The real problem is that the very cars that should give the most effect from a DPF, the low mileage short trips in town,  are also the ones that don't get the regen and suffer the problems.
It's a badly thought out, poorly implemented 'solution' that smacks of politicians getting involved in problems they know nothing about. No surprise there!

[andyc]

We now use a two stage cleaner that injected into the DPF itself, call it snake oil if you want but on every vehicle we have had in with a blocked DPF this stuff has cleaned it

The cost is around £250 but up againist price of replacing a DPF thats not as bad

Andy

[twiglet]

I have completely disabled the DPF on my 1.9 CDTi Vectra.  You can't do it with a tech2.  The ECU need to be reprogrammed.  I was able to core out the ceramic innards of the DPF with the need to cut into the casing.  I did the pre-cat while I was at it.  I also blanked of the EGR and EGR cooler. then disabled the ECU control and monitoring of the DPF, EGR and swirl flaps, as well as remapping it and backing off the smoke limiter.

The result... A big estate car that will leave a 3.2 V6 Omega in it's wake, while returning 45mpg average on a 12 mile spirited commute (3mpg) better than standard.  And no issues at all with the MOT last month.   

[chrisgixer]

That's that sorted then Twig. NEEXT

Any idea in total output?

[05omegav6]

I have completely disabled the DPF on my 1.9 CDTi Vectra.  You can't do it with a tech2.  The ECU need to be reprogrammed.  I was able to core out the ceramic innards of the DPF with the need to cut into the casing.  I did the pre-cat while I was at it.  I also blanked of the EGR and EGR cooler. then disabled the ECU control and monitoring of the DPF, EGR and swirl flaps, as well as remapping it and backing off the smoke limiter.

The result... A big estate car that will leave a 3.2 V6 Omega in it's wake, while returning 45mpg average on a 12 mile spirited commute (3mpg) better than standard.  And no issues at all with the MOT last month.   

If that list will work (where applicable) on the V6, then it may still be a contender...

[Marks DTM Calib]

You can delete the DPF with Tech 2 (fulle reset of ECU and then reconfigure from scratch) on the 1.9 CDTi, you cant disable the EGR though sadly. Similarly, if yoy had to replace the ECU then you cna program a virigin unit without DPF.

For cleaning, if you can remove it than a long soak in casutic soda plus a reverse flush does work enough to allow the car to then do a regen.

And yes, a reasonable scan tool will allow initiation the static DPF regen (although this should be avoided if possible due to the fact it only achieves a partial regen and also risks diesel dilution of the oil) 

[twiglet]

That's that sorted then Twig. NEEXT

Any idea in total output?

Not had it dyno'd yet Chris, although other cars with the same mods are seeing close to 200bhp.  It's the torque that impresses though.  She wants to torque steer in 2nd and 3rd on full boost!  Not bad for a repmobile hey

I'm currently looking at hybrid turbo and FMIC options for even more whooshy whooshy... 

[maracus]

Are these 1.9's essentially the same lump as what saab use in the TTID engines? If so, could you use the twin turbos off one of those for more oomph??

[al brown]

You can delete the DPF with Tech 2 (fulle reset of ECU and then reconfigure from scratch) on the 1.9 CDTi, you cant disable the EGR though sadly. Similarly, if yoy had to replace the ECU then you cna program a virigin unit without DPF.

For cleaning, if you can remove it than a long soak in casutic soda plus a reverse flush does work enough to allow the car to then do a regen.

And yes, a reasonable scan tool will allow initiation the static DPF regen (although this should be avoided if possible due to the fact it only achieves a partial regen and also risks diesel dilution of the oil)

[/highlight]

Agree about the risk of washing diesel into the oil and it not being a full regen, as the longer you run it the more risk contaminating the oil. However if you are in the position of have dpf lights on a run through the program and an oil change to get it running to the point you can let it regenerate itself while driving may well be a worthwhile and cheaper option.