stock dynos before and after dieselgate "fix" (increase!!)

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
for your viewing pleasure.
Same dyno, same car, obviously different days.
It seems to have GAINED power and torque after the dieselgate reflash!!!

before dieselgate update:
139 hp, 258 ft-lb

After dieselgate reflash:
146 hp, 271 ft-lb

net approx gain:
+7hp, +13ft-lb

these are NOT tuned files, 100% stock to stock comparo. everything about the car is 100% stock.
4500 ft altitude and SAE correction, sea level curve will be a slightly different shape.

Discuss.

 
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rotarykid

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Apr 27, 2003
Location
Piedmont of N.C. & the plains of Colorado
TDI
1997 Passat TDI White,99.5 Blue Jetta TDI
it is likely related to the fact that the extra power(more fuel burned) helps to get the emissions crap functioning much faster reducing NOx emissions output....

And yes this is accomplished by increased use of urea injection to counteract the extra fuel being dumped through the emissions equipment.....
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Good data. Thanks, Charlie. I'd like to see a before and after fuel economy comparison.
 

turbobrick240

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Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Nice work! I was hoping somebody would do a before/after dyno. Hard to complain about more power.
 

ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
Good data. Thanks, Charlie. I'd like to see a before and after fuel economy comparison.
So far with the dsg mpg is SLIGHTLY better. Seems to be about 1-2 mpg, with my last trip driving home from work showing 54.5 mpg going mostly 74-76 mph going up i-93 from North Reading to Londonderry NH (early am, near zero traffic), but it is tough too tell if it's the software with the recent warmer temps, but I was usually showing 51-52 on the same trip pre-fix.
It feels like it should be better mpg, as the dsg hangs onto gear longer, like most stick drivers would, and it seems to be slightly better in picking the right gear.
Just on my second tank of fuel since the fix, but I am pleased.
Nothing dramatic, just the slight improvements you might expect from a maturing product IMO. Ever notice how most motors get a slight bump in hp and tq after a couple years as a manufacturer gets more comfortable with it? Guessing we got that WITHOUT having to buy the newer model, which now will never come. Guess all the time VW spent on the dyno paid off.
 
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ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
One more thought.
How many extra miles were put on the car between the two dyno runs?
Just wondering if a good "break in" has loosened things up a bit, and is contributing to some of the gain.
 

larrydk

Veteran Member
Joined
Jul 30, 2015
Location
Brookfield
TDI
Sportwagen
DEF fluid use

Has anyone noticed an increase in DEF use after the fix?

I've had the phase 1 completed over 10k miles ago, it doesn't seem to being using significantly more....the dyno numbers are interesting, because I do feel the car is peppier since the fix, it also seems to have a "throatier" sound....

It's all that extra def fluid !! - I knew urine would solve our energy crisis :D
 

mkane

Veteran Member
Joined
Sep 22, 2015
Location
N.CA
TDI
GSW SEL 6spd
Just had my fix done Monday and you know, it felt stronger. $5045 stronger.
 

john.jackson9213

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Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Kerma,

Nice! Have to ask...What is the repeatability on that dyno with exactly the same car, engine, etc. Meaning what is the margin of error? Do you have any idea?

That graph is a 5% bump right across the curve. Nice. A big THANK You for this back to back dyno run


for your viewing pleasure.
Same dyno, same car, obviously different days.
It seems to have GAINED power and torque after the dieselgate reflash!!!

before dieselgate update:
139 hp, 258 ft-lb

After dieselgate reflash:
146 hp, 271 ft-lb

net approx gain:
+7hp, +13ft-lb

these are NOT tuned files, 100% stock to stock comparo. everything about the car is 100% stock.
4500 ft altitude and SAE correction, sea level curve will be a slightly different shape.

Discuss.

 

bora2003

Veteran Member
Joined
May 29, 2006
Location
Barstow, CA
TDI
2003 Golf GLS 5-speed; 2009 Jetta TDI 6-spd; 2010 Jetta TDI Sportwagen; 2015 Golf TDI SE - Manual 6spd; 2012 Jetta TDI
To the OP: Thank you very much for quantifying what the "seat of the pants" told me as I left the dealership today in my newly flashed TDI.

I also noticed more sound from the engine compartment; anyone else detect that??
 

CrazyMonkey

Well-known member
Joined
Sep 20, 2015
Location
Albany, OR
TDI
2015 Golf SportWagen TDI SE 6M
I had my Stage 1 fix completed on Monday and noticed it felt more responsive and it felt like it definitely pulled harder above ~2,200 rpm. I was thinking that I wished I had performed a before and after dyno run, but I came to TDIClub today and see that Kerma did just that. Thanks!

Interesting to see that where I felt the biggest gain is actually what shows up on that dyno plot too. Meaning I'm not imagining it. :D

I also hear a slightly different tone... like it's maybe a little "growlier".
 

2015vwgolfdiesel

Top Post Dawg
Joined
Jan 1, 2016
Location
Oklahoma
TDI
2015 VW Golf S DSG Silver
Has anyone noticed an increase in DEF use after the fix?
I've had the phase 1 completed over 10k miles ago, it doesn't seem to being using significantly more....the dyno numbers are interesting,

because I do feel the car is peppier since the fix, it also seems to have a "throatier" sound....

Generally I prefer quiet ~~ but as I drive with a feather toe, a little baritone under the hood might be both controllable, and a welcome change
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
The sound is definitely changed. A car guy would notice but others might not. It's not like installing an aftermarket exhaust or anything like that, it is subtle. A bit throatier under load during acceleration and more diesel clatter at times especially during warmup. But highway cruising and low load situations it is pretty much just smooth and silent.

I think this new factory calibration has less emphasis on "can't tell it's a diesel" type stuff and that's where they were able to find room to improve emissions and performance too. In the original factory calibration, I'm guessing that sacrifices were made in the name of "refinement" and with the aim of making the engine less objectionable to the largest number of people for broader market appeal. To change minds about diesel so to speak. Giving up on that vision of appealing to the largest possible number of people, freed up wiggle room to put the effort where it really matters to us diesel enthusiasts.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
The sound is definitely changed. A car guy would notice but others might not. It's not like installing an aftermarket exhaust or anything like that, it is subtle. A bit throatier under load during acceleration and more diesel clatter at times especially during warmup. But highway cruising and low load situations it is pretty much just smooth and silent.
Wonder if the timing has been advanced.
 

compu_85

Gadget Guy
Joined
Sep 29, 2003
Location
Springfield VA
TDI
... None :S
I'd think so. From what I understand the whole fuel injection strategy is different now. More injections per cycle, and new modelling routines.

I'm sure KERMA can comment on this more in depth, but from everything I've seen the fix is a lot more than a simple "re-tune".

Also, for posterity sake, we are talking about a 2015 2.0 TDI, correct?

-J
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
Wonder if the timing has been advanced.
now that's an interesting question. LOL

fair warning: what follows tries to convey something that is technically complex in overly simplified terms

TLDR answer: the "timing" as such is not adjusted from before, but changes have been made that have an effect in the cylinder that is similar to what "changing timing" would do.

These cars don't necessarily control the "start of injection" in the same way we are used to thinking of it in the older cars. Instead, the control target is ultimately the "start of combustion" when the burn starts, not the needle lift event per se. Regulating the raw "start of injection" requires assumptions regarding ignition delay, which is less precise than monitoring the burn profile. (or else its just what's been empirically mapped on the engine dyno during the initial development to meet the desired emissions target) The newer CR cars have the ability to regulate the actual burn profile by dynamically adjusting how fuel is delivered, so less guessing is needed, allowing for more precise emissions controls. Of course, then the design decisions get made as to which is the highest priority for the tradeoffs. My assumption is that they decided a bit more noise than before is acceptable in the present situation.

I guess what I'm trying to get around to saying here, is that what are thought of as the "tuning maps" so to speak are pretty much not changed from before. (wait wut? so what was "updated" lol keep reading) But there are fewer of them because the "cheat mode" has been removed.

So the answer to the question "is the timing changed" is "no" if you only look at the "tuning maps" of VCDS logs of "timing". However, the number of preinjection states is changed, and some are gone, and the selection criteria appear to be different. And rail has similar state selection changes. This has the "effect" of changing the shape of the pressure profile and what happens in-cylinder... which is what we really want. So the answer is "no" at the basic level, but it is also "yes" if you want to consider what is actually happening in the cylinder.
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
Actually one of the main inputs is something more esoteric that you may not expect, and I've never heard it mentioned anywhere before. It's called the purge ratio which consists of the ratio of intake manifold pressure to exhaust manifold pressure. Very key input to the internal regulation.
 

rotarykid

Top Post Dawg
Joined
Apr 27, 2003
Location
Piedmont of N.C. & the plains of Colorado
TDI
1997 Passat TDI White,99.5 Blue Jetta TDI
...am I getting close....

the way I understand how these things work is the glowplug is equipped with a sensor that measures precisely the combustion event while it is taking place.

And the start of injection is still at the same time but is moderated and change from previous settings which were controlled by the adjustment to improve real world driving programming.

With that programming removed adjustments of event length & quantity have been made leading to power increases. But these changes come at the cost of a shorter emissions system life after treatment parts are burned up & damaged from continual use to meet requirements now...


These changes are allowed by the increase in urea use, along with the requirement now of emissions system replacement on a schedule of @ 60k miles...

With Urea now being used more intrusively these increases, they can now inject more fuel over this time of injection in multiple events that very in quantity & duration from previous settings....

These changes are used to give a more thorough burn producing more NOx that is then burned off to some extent by the injection event changes along with the urea taking care of the rest....

the changes have allowed an entirely new scheme of injection mapping to be used for what was possible with the old programming...And

am I getting close...
 

rotarykid

Top Post Dawg
Joined
Apr 27, 2003
Location
Piedmont of N.C. & the plains of Colorado
TDI
1997 Passat TDI White,99.5 Blue Jetta TDI
Actually one of the main inputs is something more esoteric that you may not expect,

and I've never heard it mentioned anywhere before.

It's called the purge ratio which consists of the ratio of intake manifold pressure to exhaust manifold pressure.

The Very key input to the internal regulation.
So what exactly does the "purge ratio" describe..?...

Are they describing the injection changes which create a characteristic of combustion that helps to more thoroughly remove used combustion gasses while taking in clean air to burn..?...

How does this effect EGR use?? how does it change EGR programming, low & high pressure..??..
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
So what exactly does the "purge ratio" describe..?...
Are they describing the injection changes which create a characteristic of combustion that helps to more thoroughly remove used combustion gasses while taking in clean air to burn..?...
How does this effect EGR use?? how does it change EGR programming, low & high pressure..??..
Pretty much just input intake and exhaust pressure, fuel IQ and air IQ, and you can accurately measure how well the engine is working. The fuel trim adjustment from glow plugs and IVA/IMA and lambda and the active eeprom adaptations for air/boost/actuator in order to be precise as possible.

EGR and throttle(s) and all that stuff matters... of course. Not really able to adequately discuss in a sentence or two in a forum post but it all matters.
 

Arin@APR

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Jul 24, 2012
Location
Auburn, AL
TDI
MK4 Jetta, MK5 GTI, B8 S4, MK7 Sportwagen TDI
Do you have an overlay with correction turned off? When stock, the ecu is already correcting for altitude/temperature so dyno corrections will skew results.

Example:

Hot weather: ECU asks for more out of the engine to make up for the losses due to the poor conditions. Then the dyno correction artificially adds power to the graph. Result: higher than expected figures.

Cold weather: ECU asks for less out of the engine because conditions are good and less is needed from the engine to produce the prescribed power levels. Then the dyno correction artificially lowers power on the graph. Result: lower than expected figures.
 

r11

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Mar 6, 2012
Location
NJ
TDI
2012 Passat TDI SE 6MT (BB'd), 2015 Passat TDI SE 6MT
A DSO == injection timing diags. A good project for a automotive or eeng student.

2 channels, one tapped into the piezo on the plugs, so you can see the pressure in the cylinder, another one into the injector control wire.
 
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IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
FWIW I'm seeing 46 MPG in mixed driving on my GSW (MFI, not calculated). First fill, 600 miles on the car. Even if it's optimistic that's pretty impressive.

I find the response to the acclearator a bit flat on tip in, noticeable when taking off from a stop. Otherwise driveability seems fine. Of course it's not like my modified ALH, but it doesn't seem to have any issues.
 

ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
FWIW I'm seeing 46 MPG in mixed driving on my GSW (MFI, not calculated). First fill, 600 miles on the car. Even if it's optimistic that's pretty impressive.

I find the response to the acclearator a bit flat on tip in, noticeable when taking off from a stop. Otherwise driveability seems fine. Of course it's not like my modified ALH, but it doesn't seem to have any issues.
Yup.
Very impressive in stock form. I have been pleased with mpg with my DSG, often hitting similar numbers to the stick guys, so it seems I have not given up much.
It a shame it appears this motor will be the last of the TDI's...it sounds like VW might not invest in any future generations to move on to electric, even in the euro market due to "market forces" aka politics.
 

Yawiney

Veteran Member
Joined
Apr 25, 2014
Location
Northern California
TDI
2015 GSW DSG
These MPG sound better than my '10 unfixed JSW and i believe it after test driving one.
Big difference in torque in my experience though. If i get one i'll be having to use sport mode. Never use in in my current car.
 

Yawiney

Veteran Member
Joined
Apr 25, 2014
Location
Northern California
TDI
2015 GSW DSG
the way I understand how these things work is the glowplug is equipped with a sensor that measures precisely the combustion event while it is taking place.
And the start of injection is still at the same time but is moderated and change from previous settings which were controlled by the adjustment to improve real world driving programming.
With that programming removed adjustments of event length & quantity have been made leading to power increases. But these changes come at the cost of a shorter emissions system life after treatment parts are burned up & damaged from continual use to meet requirements now...
These changes are allowed by the increase in urea use, along with the requirement now of emissions system replacement on a schedule of @ 60k miles...
With Urea now being used more intrusively these increases, they can now inject more fuel over this time of injection in multiple events that very in quantity & duration from previous settings....
These changes are used to give a more thorough burn producing more NOx that is then burned off to some extent by the injection event changes along with the urea taking care of the rest....
the changes have allowed an entirely new scheme of injection mapping to be used for what was possible with the old programming...And
am I getting close...
How much is the emissions system replacement going to cost?
 
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