But Fiat do seem to have done this already.
If you read back over this thread you'll see what's happening to my clogging % value - it rises at 5.2% per hour, regardless of how the car is being driven. I suspect that clogging % is a misnamed variable. It looks to be a timeout timer to me
The physical clogging rate at 70mph in 5th gear on the motorway is different to the clogging rate when just pootling around town. Yet for all I can see, from recording hours of driving (graphs in this thread show the results)...the clogging rate rises with a constant value. The only constant which was rising at a uniform rate during my test, was time.
Why not ?
The only conceivable benefit of having a remap is to prevent the regenerations from taking place.
What are the benefits to removing the blocked dpf or drilling it out ? Improved mpg for a start, lower regeneration temperature (cited in the SAE papers mentioned in the thread), and possibly shorter duration regens.
What are the associated costs when you compare a car which is remapped to remove regen cycles, compared to one which hasn't been remapped ?
The fuel saving, based on 1 regen every 20 hours, lasting 12 minutes and using 25% more fuel, is about 3 minutes worth of driving in 1203. (reasonable figures based on measurements and experience with a less clogged dpf)
A remapped car can travel for 1203 minutes on the same amount of fuel that a non remapped car can travel on for 1200 minutes
3/1203 x 100 = about 0.25% improvement in mpg when regen cycles are prevented from happening
To recover the cost of a £200 remap at a fuel cost of £1.45 /litre and a saving of 0.25%
0.25% of £1.45 = 0.36p saving per litre
£200 = 20000p, 20000/0.36 = 55,555 litres of fuel needs to be bought to recover the cost of the remap
In gallons thats 55,555 x 0.22 = 12222 gals.
This means that at 35mpg consumption you would need to drive for over 420,000 miles before you recover the cost of the remap through fuel savings.
Or in other words it might just be better to stick with a bypass pipe, a hollowed out dpf or a partially reshaped dpf, because you will lose money on a remap unless you drive for another 420,000 miles in that car.
Of course, the benefit of drilling a dpf which doesn't need it, or getting a dpf delete when the dpf is working perfectly well, is always going to be questionable.
One of the things I'm trying to do with this thread is find a method to quantify the symptoms of a blocked dpf from something other than 'sluggish sometimes and a bit thirsty'. (Those were the only real symptoms in my car. )There may well be other factors involved wihich are causing those problems.
Therefore (just IMHO) before anyone even thinks of getting a dpf delete/remap, or drilling out the dpf or fitting a bypass pipe, the best thing you can do is to measure the pressure in the dpf itself. Because yiou need to know - is it blocked or isn't it ?
Either through the use of an electronic diagnostic tool, or a phyical pressure gauge repeat the test outlined a few messages ago. Check the pressure at 1000-3000 revs, at 500rpm intervals and compare them to my figures or the ones posted by Fireman (who seems to have a pretty clear dpf). In fact, just by checking the pressure at 3000rpm ought to be a good enough indicator of how well the dpf is flowing.
I'm not trying to take anything away from the artful nature of the work of the tuners who do remaps. Clearly an EGR delete is bonus whichever way you look at it, but a dpf delete on it's own would be remapping for remapping's sake as far as I'm concerned. Some of the ECU tuning forums I visit indicate to me that there are several ways that dpf regeneration action is negated. The one which seems to be the best is the one which allows the regen to to take place as a result of the related software parameters telling it to happen, but then set the fuel IQ for the regen fuel pulse to 0%. But I've read about guys getting into trouble by trying to mask out things like the differential pressure measurement, which comes back to bite them when they learn that the pressure is used during other parts of the driving cycle, not just during regeneration (depending on the engine type used).
Since hollowing out my dpf about 10 days ago I've travelled over 700 miles and had one regen. There have been no ECU faults when I've checked for them with diagnostic software. I don't know if the regeneration tuning routines are going to slacken off and reduce their frequency or not so I suppose I'll have to watch this some more over time.
In fuel saving alone it has been worth it for me and the way the torque picks up at low revs now just makes it that bit better.
So all I can conclude now is that my dpf must have been badly blocked, but there was no dpf warning light (god knows when that is set to come on ?) and it was costing me a fortune in fuel to live with it (only I didn't know that at the time)
My feeling now is that if you measure the pressure in the dpf and find it is high, it can only be because the dpf is clogged beyond help. Of course, some more data from other users would be a goldmine for the future as far as data quality is concerned