Differences V.A.G. Engines AFN, AHH, AHU

Hello everyone,
it concerns the 1.9TDI engine from VW/Audi; I am currently trying to find out how the differences in torque relate to... Explain the performance.
AHU 66kW (90PS) => 202Nm
AHH 66kW(90PS) => 210Nm
AFN 81kW(110PS) => 235Nm

The engines are identical, based on their precise specifications (bore, stroke, compression ratio, valves, etc.).

ALL THREE have AGR, VTG, LLK, E-Gas, and the same boost pressure, and everything else that can be seen is the same.
The difference can't just be due to the control unit.
Where would be the point?
Same performance, different results. Torque, can't it only come from the characteristics?

I have tried to familiarize myself with VW literature and various articles online, but I am not really convinced by my conclusions.
Does anyone perhaps know exactly what can also be verified?

Best regards, Alex

The AHU has 210 Nm and no VTG (202 Nm was the 1Z)


That's already a difference.

The AHH could be a Euro 3 AHU - in the G3 Var, the Euro 3 was a 90 PSer ALE

m;

As far as I know, AHU=1Z and AFN do not have the same boost pressure.

alexmagnum+ wrote:

Same performance, different results. Torque, can't it only come from the characteristics, or?

But you are missing the connection between... Torque and power are not entirely clear, are they?
P=M*Omega
The highest values are always specified, with Pmax around 4200 and Mmax around 2000-2500 (as approximate values).
And the torque results from the amount of fuel injected.
So, if the turbocharger can generate more boost at lower engine speeds (see AHH-AHU), then more air can be injected, and the torque will be greater at the same power output.

Providing basic knowledge is actually not the goal of this forum.

Quote:

This page is intended for information exchange for people who already have extensive basic knowledge of automotive technology.

The AFN is already excluded from this list, as it is the only one with VTG.

Loading pressure can be found in the tables labeled "TDI 4-cylinder target values".

Search

m;

.... basic knowledge course 2:

...the engine has larger fuel injectors... -> more fuel injected at the same time -> more power -> but also more boost pressure is required (see the specifications of the 4-cylinder VW TDI engines)
and, as already mentioned, in relation to the ahu, there is a VTG loader

and basic knowledge course 3:

The search function here is not implemented for fun and does not cause any problems when used. It doesn't crash, doesn't scream, and doesn't get angry or fussy!

Okay, now I'm smart.

The AHH has a VTG (same turbo as AJM, AVG, and some AFN) - it should be similar to an ALH.

m;

AHH=ALH for engines mounted lengthwise
AHU=1Z, as far as I remember
ALE=AHU with Euro 3
ALH = ALE with VTG Loader
AVG = AFN with Euro 3, if I recall correctly

Best regards, WarLord

Can the AHU also be upgraded to Euro 3, like the ALE? ...apparently, there aren't any AHU-specific filter options available.

Hello,
I find most of what you're writing to be quite interesting, but I don't agree with some of it.

All three engines definitely have a VTG (Variable Transmission Gear) charger.

The charger from the AHU is, admittedly, a different design, but it is still a VTG.
(could, of course, also result in a different turbine geometry)

Both the original VW repair manual and various commercially available repair manuals specify a torque of 202 Nm for the AHU engine.
(NOT 210Nm!!!)

Also, according to the technical data, the boost pressure is also identical (AHH, AHU).
The AFN is, of course, excluded.

The mention of the larger injectors is definitely a step in the right direction, although I'm not sure if the injectors of the AHH are identical to those of the AHU.
At the AFN, I understood this (even though I didn't know it).


Question: Where do you get your data from?


ALH is not the same as AHH.

And if I have understood correctly, the cable harness of the ALH is quite different from the AHH, and the ALH was also installed transversely in the Golf.

What is written 'somewhere' does not necessarily have to be correct, simply because it is written.


And even in your contributions (for which I am, by the way, very grateful), different or, in some cases, incorrect information is conveyed.

Also, I also checked the list of recommended 4-cylinder values, but the AHH is not included at all.

Essentially, I was focused on the 8 Nm difference between AHU and AHH, but more so on the practical application aspect rather than the research aspect.
Why should a manufacturer go to all this trouble if they are essentially selling the same engines?


(by the way: I'm interested in the relationship between M and) Okay, that's clear, but the practical application in this case doesn't really make sense; nevertheless, thank you for your statement, I will work on my way of expressing myself.

Best regards and thanks, Alex

Hi Alex, I haven't finished reading.

But please show me an AHU with VTG - but that doesn't exist.

My source: HINGUCKEN!

Ask VW

m;

Unfortunately, the AHU does not have a VGT turbo... neither does the 1Z.

However, my vehicle logbook states that the 90hp engine has a 202NM engine code, but the specific engine code is not mentioned there. I believe they are referring to the 1st.

Hm,

Is this really 8 Nm?

You won't even notice them while driving.

And that the AHU doesn't have a VTG, I know, I'd bet my Wastegate charger on it.

m,
1Z with 202 Nm and Wastegate charger

Hello Martin and everyone else,
I'll take a look to see if I can find an image that exactly illustrates this and then post it.

Maybe someone here knows - if the AHU actually doesn't have a VTG - what the VTG-typical pressure gauge with a rod is actually for, exactly on the turbo?

Okay, I admit I haven't disassembled the AHU Turbo.

Best regards, Alex

Hi,
Addendum:
No, it's not about the 8Nm in itself, but rather about the
'Why choose another engine type(?)'
'What does 'additional expenses in construction, manufacturing, and service' mean?'

Best regards, Alex

@ Alex

meinst du das:
http://www.luxus-wg.de/~martin/auto_bilder/Kruemmer/Kruemmer_draussen.jpg

That's the wastegate for the wastegate.

Unfortunately, I didn't take any photos of the WG, but it fits into the small indentation:
http://www.luxus-wg.de/~martin/auto_bilder/Kruemmer/Abgasrohr.jpg
and allows exhaust gases to pass by the turbine blades.

The 1Z-AHU difference is minimal; some say that VW is the engine number for the 1Z, but I think that the switch from the MSA12 to the MSA15 mainly caused the new MKB, which could also explain the 8Nm.

Since the 1Z had Flexrohr issues, the AHU was then given an AFN Flexrohr.

I can provide pictures of the 1Z and AHU Flexrohr (I have them at home).

Here's the short 1Z:
http://people.freenet.de/golf-schrauber/getriebe.jpg

m;

hi martin,
Thank you for the quick response.
I think you're right.
I thought the rod was supposed to go to the charger, but probably it goes past the charger and to the manifold (after everyone else – except me – also agreed on this).

Actually, I could have figured it out myself, but maybe I was seeing what I wanted to see.

Sorry, for my nervousness about this.

Regarding the MKB, I am not yet completely satisfied.

In the VW Repair Thread, it states that AFN is being replaced due to {REASON}. AVG replaces the previous method of {METHOD_NAME}.
but I was unable to establish the connection 1Z to AHU in this form.


Thank you very much, Best regards, Alex