Volkswagen under investigation over illegal software that masks pollution

[Greg Roles]

Lots of things can casue odd dyno curves, plus the myriad of settings and ways torque can be derived, I would not worry about the 1750 bit. I'm much more concerned about the difference down low, regardless where it shows up, but again the two runs would have been some time apart as the "fix" had to be supplied, and there would be differences in runs right down to how hard it was tied down, but still the difference is worrying.

[Ryeman]

Lots of things can casue odd dyno curves, plus the myriad of settings and ways torque can be derived, I would not worry about the 1750 bit. I'm much more concerned about the difference down low, regardless where it shows up, but again the two runs would have been some time apart as the "fix" had to be supplied, and there would be differences in runs right down to how hard it was tied down, but still the difference is worrying.

But surely there was an original brochure graph confirming 1750 as the peak? For a diesel 900rpm is a very big miss.....at least on a graph.
But agree, the tables indicate a big miss on the 1800rpm lower figure anyway.
Sub 2600 - emissions testing, but above that ideal for European motorway speeds looks to be the devised outcome.

[Greg Roles]

Bottom line is those two powercurves would drive very differently, and so far the few guys commenting are saying they can feel nothing. 50nm down low is a mild tune gain, you'd notice that!

[Ryeman]

Bottom line is those two powercurves would drive very differently, and so far the few guys commenting are saying they can feel nothing. 50nm down low is a mild tune gain, you'd notice that!

Don't forget it's a UK test and the figures are ft/lbs (and bhp) BIG ones, ~70 mm and between 1600 and 1800 rpm the drop is 40% and 35%
You'd certainly feel that
(why the torque graph confirms max before and after occurring at 2600 is a diesel mystery to me, because 1700-2000 is the norm these days)

[Ozsko]

Link to original graph?

[Ryeman]

Link to original graph?

It was post #1378
.....and again
https://onedrive.live.com/?authkey=%...%21104&o=OneUp

[Ozsko]

Sorry, wrong question, link to original post 1378, PH is has so many sub forums it is a nightmare to find anything in. Thanks.

[Ryeman]

The bottom line for those stuck with the EGR cooler equiped 2.0TDIs and thinking of whether to do it or not, is to demand from a dealership a graph of the details after the fix.
The SCR ones now are free of this dreaded EGR at least and are worth trading up to IMO.
The legal consequences of a failure to maintain the driving characteristics and economy are probably many months if not years away, in the meantime I'd certainly be avoiding the 'fix' until VW can substantiate their 'claims' and in the absence of hard evidence from VW to the contrary.

[Greg Roles]

I think you men DPF mate, the lastest cars have very complex EGR systems now. EGR is there to displace inlet O2 and thus control cylinder temps, DPF and SCR are post engine exhaust treatments ( obviously ).

[Ryeman]

I think you men DPF mate, the lastest cars have very complex EGR systems now. EGR is there to displace inlet O2 and thus control cylinder temps, DPF and SCR are post engine exhaust treatments ( obviously ).

Hi Greg but didn't we discuss this before
The DPF remains but AFAIK the EGR was all about control of combustion peak temps also producing NOx peaks, but the adoption of SCR enables engine combustion performance to be optimised with increased NOx subsequently treated (reduced by 90%) by the injection of AdBlue between the catalyst and DPF .
I understand it's a NOx reduction not DPF relatated..........?