VW Dieselgate fix

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Wed 25 Nov 2015 18:33
VW Dieselgate fix - Trilogy

www.honestjohn.co.uk/news/volkswagen-emissions-sca.../

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Wed 25 Nov 2015 20:09
VW Dieselgate fix - craig-pd130

The 'flow straightener' for the 1.6TDi strikes me as odd. Must be a quirk of the 1.6's airbox architecture that doesn't apply to the 2.0

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Wed 25 Nov 2015 23:25
VW Dieselgate fix - Wackyracer

The thing sounds like some dubious device usually sold under the impression of giving more power and MPG.

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Wed 25 Nov 2015 23:36
VW Dieselgate fix - gordonbennet

That flow straightener sounds like something a politicians spin doctor would dream up in order to take attention from the real fix, the software updates.

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Thu 26 Nov 2015 07:33
VW Dieselgate fix - Engineer Andy

Odd - a mesh doesn't sound like it 'straightens' the flow at all - 'turning vanes' would do the job in an air duct. For the rest - a software 'fix' sounds like a drop in power to me, otherwise why haven't they already used it instead of the 'cheat' software?

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Thu 26 Nov 2015 09:38
VW Dieselgate fix - craig-pd130

For the rest - a software 'fix' sounds like a drop in power to me, otherwise why haven't they already used it instead of the 'cheat' software?

I suspect VAG will have engineered the software update so that the engine still produces the original, quoted maximum power output at peak revs.

But it's hard to see how they can maintain the same on-the-road driveability (i.e. throttle response and pick-up from low / mid-range) while reducing NOx emissions.

The only way to reduce NOx is recycling more exhaust gas and/or injecting more AdBlue at zero and light throttle = less oxygen available for combustion = less power at the same throttle position and rpm than previously.

If any of the big motoring magazines are on the ball, they should do a test drive and take performance figures on a car immediately BEFORE the VAG modifications, and repeat the performance benchmarking immediately AFTER the update to see how it affects the driveability.

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Thu 26 Nov 2015 10:07
VW Dieselgate fix - RT

It seems the cheat software isn't illegal in Europe, due to lax regulation, but the investigations have discovered excess CO2 readings which the recall is designed to fix.

NOx is a wider issue affecting all brands because the current pussy-foot test is so unrepresentative of real world driving - so as long as the recalled VW's meet the NOx level on test, it's "ok" for them to carry on with high NOx outputs in real life, just like the other brands.

NOx levels in congested cities won't get any better until the new real-world test and Euro 7 limits are applied - unless restrictions are placed on diesels going into cities, but that hits public transport more than private.

In the US however, the cheat is illegal even in states that do no emissions testing at all. It looks likely that the 4-cylinder cars there fitted with Lean NOx Traps (LNT) will need to be retro-fitted with DEF/Adblue systems, or bought back where it's cheaper.

Edited by RT on 26/11/2015 at 10:09

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Thu 26 Nov 2015 10:58
VW Dieselgate fix - RobJP

I suspect VAG will have engineered the software update so that the engine still produces the original, quoted maximum power output at peak revs.

Agreed. I can see it now : We sold you a car with 140bhp, and it still produces 140 bhp !

The fact that it produces considerably less than 'original' at most areas of the rev band will be glossed over, if possible.

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Thu 26 Nov 2015 11:04
VW Dieselgate fix - gordonbennet

shudder...memories of too many turbo Diesels driven gutless below a certain revs, then whoosh off we go only to have to change up three seconds later due to the stupidly short power band, makes moving junctions a hoot, not.

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Thu 26 Nov 2015 11:07
VW Dieselgate fix - Wackyracer

Agreed. I can see it now : We sold you a car with 140bhp, and it still produces 140 bhp !

That is assuming it ever had the specified 140bhp in the first place (which it most likely didn't)

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Thu 26 Nov 2015 12:13
VW Dieselgate fix - craig-pd130

That is assuming it ever had the specified 140bhp in the first place (which it most likely didn't)

I can't speak for the current generation of engines, but the older PD diesels were fairly well-known for exceeding their rated output.

In the early 2000s when I had a Passat B5.5 PD130, I used to frequent various Seat, Skoda, VW and Audi forums, and many owners had dyno'd their standard cars. It was common for the PD motor to show its rated output at the wheels, i.e. a good 10 - 15% higher than specified at the flywheel.

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Thu 26 Nov 2015 12:54
VW Dieselgate fix - gordonbennet

Wonder how many 1.9 PD owners have spent the last 5/10 years stuffing their steeds with rustproofing product and overservicing them like billio to make them last as along as possible and avoid the replacements.

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Thu 26 Nov 2015 14:00
VW Dieselgate fix - slkfanboy

>The only way to reduce NOx is recycling more exhaust gas and/or injecting more AdBlue >at zero and light throttle = less oxygen available for combustion = less power at the same >throttle position and rpm than previously.

In the case of VW the NOx is being produced as the engine run lean under load. The large amounts fo NOx produced by doing this are stored in a NOx trap. Once the NOx trap is full the NOx is burnt with with an enriched fuel mixture (rather than a lean one). This cycle of run lean then running enriched for short burts saves fuel and maintain lowish level fo NOX. The cheat software disable the enchriched fuel cycle increasing MPG but also NOx output.

It makes sense to swirl the air as many engines have such devices to improve fuel mixture. The downside is going to be MPG is lower.


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Thu 26 Nov 2015 14:17
VW Dieselgate fix - RT

>The only way to reduce NOx is recycling more exhaust gas and/or injecting more AdBlue >at zero and light throttle = less oxygen available for combustion = less power at the same >throttle position and rpm than previously.

In the case of VW the NOx is being produced as the engine run lean under load. The large amounts fo NOx produced by doing this are stored in a NOx trap. Once the NOx trap is full the NOx is burnt with with an enriched fuel mixture (rather than a lean one). This cycle of run lean then running enriched for short burts saves fuel and maintain lowish level fo NOX. The cheat software disable the enchriched fuel cycle increasing MPG but also NOx output.

It makes sense to swirl the air as many engines have such devices to improve fuel mixture. The downside is going to be MPG is lower.


Expect to see all new diesels with DEF/Adblue systems instead of the cheaper LNT trap technology - the DEF/Adblue systems have the added advantage of dispensing with the EGR.

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Thu 26 Nov 2015 15:32
VW Dieselgate fix - galileo

Once the NOx trap is full the NOx is burnt with with an enriched fuel mixture (rather than a lean one).

NOx is already burnt, it is a mixture of oxides. Mixing it with extra fuel is using it to provide oxygen to burn the fuel, freeing the original Nitrogen, isn't it?

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Thu 26 Nov 2015 16:39
VW Dieselgate fix - Engineer Andy

I know when Mazda updated the mk1 Mazda3 (mid-life update to 1.5 in mid 2006), they re-mapped the engine (i.e. a software change) so that the 1.6 petrol dropped at least one CO2 group and gain a bit of mpg (same engine as my mk1), but at the cost of 0.5 sec in the 0-60mph time.

Sounds like something similar may happen here, though it may have a larger impact as you say outside of the peak power band. It'll be interesting to see the difference before and after.

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Tue 8 Dec 2015 11:03
VW Dieselgate fix - colino

Pretty sure the molecule straightener, which look like two cheap MAFs bought from ebay and glued together, are the red herring while VAG lawyers work out what other pain will be unleashed on them if they actally start "fixing" cars.

Doubt very much if the fix will be anything more than a reflash of the ecu, but they aren't miracle workers. If the cars then uniformly meet emmision rules, they aren't going to perform the same or give the same economy. One queue I wouldn't be planning to be at the head of.

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Tue 5 Jan 2016 09:39
VW Dieselgate fix - Trilogy

HL Website - The US government is suing Volkswagen for up to $80 billion (£54.3 billion) over an emissions-cheating scandal that has affected hundred of thousands of vehicles in the US and millions worldwide. The Justice Department lawsuit will be filed in the Eastern District of Michigan and then transferred to Northern California, where class-action lawsuits against Volkswagen are pending.

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Tue 5 Jan 2016 10:14
VW Dieselgate fix - RT

HL Website - The US government is suing Volkswagen for up to $80 billion (£54.3 billion) over an emissions-cheating scandal that has affected hundred of thousands of vehicles in the US and millions worldwide. The Justice Department lawsuit will be filed in the Eastern District of Michigan and then transferred to Northern California, where class-action lawsuits against Volkswagen are pending.

That's to put pressure on VW Group as they're thought by the US authorities to be dragging their feet - nothing concentrates the mind more than a $80 billion lawsuit but the US government!

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Tue 5 Jan 2016 12:55
VW Dieselgate fix - DirtyDieselDogg

Ah kin unnerstann an " 'air straightner" in an Audi TT, but quite what it got to do with diesel engine emissions I cannot fathom!

signed,

Disapointed of Dervock

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Tue 5 Jan 2016 14:23
VW Dieselgate fix - DirtyDieselDogg

OOps

I "understand" that most VAG group diesels put out well in excess of/significently in excess of their stated or declared HP, as evidenced by many rolling road tests, admittedly mostly by VW fanboys, which would give VAG some "wriggle" room.

cheers

M

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Tue 5 Jan 2016 15:22
VW Dieselgate fix - jgrahampo

Hair straighteners!

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Tue 5 Jan 2016 21:05
VW Dieselgate fix - DirtyDieselDogg

Aye Lad, tha's wot ah said h'air straightners!

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Tue 5 Jan 2016 21:06
VW Dieselgate fix - DirtyDieselDogg

Aye Lad, tha's wot ah said h'air straightners!

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