VW in trouble over alleged US emission test manipulations
Discussion
liner33 said:
Would be interesting to get a before and after dyno comparison. I cant help thinking the fix for the 1.6 engine will reduce the engines output
Indeed. If the solution is as simple as a re-map and a bit more accuracy on the AFM/MAF why did they go through the effort and risk of cheating?Megaflow said:
Because the 'flow straightener' will also coincidentally reduce the intake area by a significant percentage, as such the fuel will need to be reduced to balance.
Less fuel = Less emissions.
Less power as well.
As I've already said some posts up, this wouldn't be a useful way of reducing emissions in a typical NDEC test. If the mesh provided sufficient restriction at the low engine RPMs used in this test, it would be so restrictive at high RPM that the thing would barely run.Less fuel = Less emissions.
Less power as well.
Since any modern diesel has ECU control over turbo boost anyway, why wouldn't they simply reduce boost rather than strangle the air intake?
.Mr2Mike said:
Megaflow said:
Because the 'flow straightener' will also coincidentally reduce the intake area by a significant percentage, as such the fuel will need to be reduced to balance.
Less fuel = Less emissions.
Less power as well.
As I've already said some posts up, this wouldn't be a useful way of reducing emissions in a typical NDEC test. If the mesh provided sufficient restriction at the low engine RPMs used in this test, it would be so restrictive at high RPM that the thing would barely run.Less fuel = Less emissions.
Less power as well.
Since any modern diesel has ECU control over turbo boost anyway, why wouldn't they simply reduce boost rather than strangle the air intake?
EricE said:
IMO if this new device they came up with does anything, then it's because it functions as a Venturi that restricts the airflow.
It's also dirt cheap (< £1) and in a very convenient location for the retrofit.
Restricted airflow = richer combustion = lower NOx
if you assumed that the centrelines of the squares are at 6mm c/c and the squares have 5mm sides then that's a reduction in csa of about a quarter which you would have thought would affect full flow results.It's also dirt cheap (< £1) and in a very convenient location for the retrofit.
Restricted airflow = richer combustion = lower NOx
TA14 said:
if you assumed that the centrelines of the squares are at 6mm c/c and the squares have 5mm sides then that's a reduction in csa of about a quarter which you would have thought would affect full flow results.
Quite possibly there will be a slight increase in pressure drop at max power, but that's pretty irrelevant to fixing the problem since that's not where CO2/NOx outputs are tested. Why would they slightly strangle the input at maximum power to fix the emissions measured at part throttle, especially when the ECU has full control of boost?Have to agree with Mike there..
Yes it might have have a (very slight) impact on max bhp if airflow is restricted, but that is not the reason for doing it, as on cycle you're lucky if you use 20% of the total bhp, let alone maximum output!
Otherwise you could stick some gaffer tape to cover half the intake, and miraculously solve the emissions problem? No.
Yes it might have have a (very slight) impact on max bhp if airflow is restricted, but that is not the reason for doing it, as on cycle you're lucky if you use 20% of the total bhp, let alone maximum output!
Otherwise you could stick some gaffer tape to cover half the intake, and miraculously solve the emissions problem? No.
skyrover said:
Please share 
We can't do the certified emissions tests, because you need a lot more kit than we've got, but I can do drive cycles and sample analysis.We will wait until we get close to the recall date, then measure everything we can before and after.
May not be for months yet.
TA14 said:
if you assumed that the centrelines of the squares are at 6mm c/c and the squares have 5mm sides then that's a reduction in csa of about a quarter which you would have thought would affect full flow results.
The airflow merely speeds up through the restriction, so the overall flow isn't affected much - give or take friction lossesHere is a brilliant video by 2 guys, one an ex vw it guy who reverse engineered the code from an adblue utilising vw to see what they're doing:
http://youtu.be/xZSU1FPDiao
Basically it seems they're mostly under dosing the adblue by putting it into a fail safe mode where it under doses to make sure it doesn't produce ammonia if a sensor fails, they did this fairly amazingly
50 minutes onwards is the most interesting.
http://youtu.be/xZSU1FPDiao
Basically it seems they're mostly under dosing the adblue by putting it into a fail safe mode where it under doses to make sure it doesn't produce ammonia if a sensor fails, they did this fairly amazingly
50 minutes onwards is the most interesting.
Kolbenkopp said:
Don't think that Felix (the guy who reverse engineered the software) has any links to VW. Doesn't make the video any less interesting. Absolutely worth watching and brilliant work.
Sorry my post is badly worded, the first chap to speak (Daniel Lange) is an ex VW IT specialist.I think Daniel once worked for BMW (see here on his intro slide: https://youtu.be/xZSU1FPDiao?t=1m51s )
Anyways, very interesting work and presentation!
Anyways, very interesting work and presentation!
Bodo said:
I think Daniel once worked for BMW (see here on his intro slide: https://youtu.be/xZSU1FPDiao?t=1m51s )
Anyways, very interesting work and presentation!
Ah cock yes, I'm not sure what I was convinced it was vw!Anyways, very interesting work and presentation!
Interesting presentation.
This slide summarizes the whole mess.
It seems VW went *way* overboard
No Dosing = engine warming up, etc
Regular Model = ECU detects test cycle conditions met -> emissions treatment fully enabled
Alternative Model = ECU detects test cycle conditions not met -> emissions treatment mostly disabled
This slide summarizes the whole mess.
It seems VW went *way* overboard
No Dosing = engine warming up, etc
Regular Model = ECU detects test cycle conditions met -> emissions treatment fully enabled
Alternative Model = ECU detects test cycle conditions not met -> emissions treatment mostly disabled
Edited by Seek on Wednesday 30th December 04:55
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