AAZ Engine Power: How Much Without LLK?

The title pretty much says it all!

How much power can you extract from a 1.9L AAZ turbocharged diesel engine without installing an intercooler?
We have now decided to install this engine in our T3 instead of the 1.6 TD JX.
The ESP, turbo, and all other add-on parts will be taken from the JX model. Only minor modifications are needed for everything to work!

In my Audi 80 repair manual, the engine is specified as having a power output of 75 horsepower and 150 Nm of torque at 2200 RPM. It also states that the engine is only lightly turbocharged. Is it possible to increase the boost pressure slightly?
We really wanted the engine to have around 85-90 horsepower.
Tell me what you know about the engine!

Have a good evening.
Regards,
Sausage blinkers.

Hello,

Right now, the engine in the bus probably runs under higher load more often than in a Golf! So, the engine is already under more stress in this situation. I wouldn't even attempt to increase the power without an effective low-temperature cooling system.

Best regards, Rainer.

Thank you for your reply!

Could you perhaps briefly explain why the load on the engine is lower with low-temperature coolant? I'm missing the connection!
Colder intake air - less stress - more power???
It's not about top speed here, but about not having to crawl up the Kassel mountains in second gear on the way to your vacation.

I am grateful for any advice!

Sure, here is the translation of the text from German to English:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which means 'Sincerely' or 'Best regards' in English.

Hi,

Even though it can be difficult to fit a larger radiator in a T3, it's worth the effort. You should also consider a proper oil cooler. You'll be rewarded with improved stability.

Hello,

An intercooler significantly reduces the temperature of the intake air. The compression of the intake air by the turbocharger increases the temperature to over 100°C.
With an intercooler, for example, with my AHF engine and a boost pressure of 1.1 bar, you would only reach around 60°C in the height of summer.
The LLK (Low-Pressure Cooling System) therefore relieves the entire cooling system and reduces combustion and exhaust gas temperatures.

Best regards, Rainer.

"It should be possible to reliably extract 100 horsepower from the engine with an intercooler. Simply increasing the boost pressure, in my opinion, doesn't achieve much, as Rainer pointed out in his post."

Otherwise, take a look around, especially in the forum.
http://www.golf3td.tk/

Okay.
However, the GolfTD website also mentions an increase in boost pressure from 0.6 to 0.9 bar without an intercooler.
And what's the point?

Sure, here is the translation of the text from German to English:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which means 'Sincerely' or 'Best regards' in English.

Hello,

With higher boost pressure, you can increase the fuel injection volume without the vehicle starting to produce excessive black smoke.

Best regards, Rainer.

Hi there,

If you browse through the various VW bus forums, you'll see that the AAZ engine in the bus has the exact same temperature problems as the JX engine.
If you install the charger and pump from the JX model, you're likely already doing the AAZ modification, as far as I know. However, you should only do this in conjunction with LLK (low-temperature coolant) and an oil cooler, otherwise, you won't have much fun with it for long.

greetings
dieter

The page doesn't mention anything about being able to increase the boost pressure to 0.9 bar without an intercooler. It states that adjusting the fuel injection pump is only worthwhile with an intercooler (and that the fuel injection pump needs to be adjusted if you increase the boost pressure). It also says that 0.9 bar is a good value, but always in conjunction with an intercooler. Increasing the boost pressure is also a way to compensate for the pressure loss in the intercooler caused by the cooling of the air.

Increasing the boost pressure to 0.9 bar without using LLK, I believe, is a death sentence for the engine.

Hello Christian,

Stukov wrote:

Increasing the charging pressure is also a way to counteract the pressure loss in the intake manifold caused by the cooling of the air.

Sorry, but that's nonsense. The air is cooled isobarically, meaning that the cooling process itself doesn't cause a pressure drop, or any pressure drop is immediately compensated for from behind. At most, a slight pressure drop (about 0.05 bar) may occur due to the flow resistance along the path from the charger to the intercooler to the engine. If I have the intercooler installed in the bus, I'll measure it precisely.


@Wurstblinker: The thermal stress on components like the pistons, cylinder head, and seals increases disproportionately with the boost pressure. If the intake air is cooled, you can increase the pressure without negative consequences; in fact, the thermal stress is even lower than in the original, uncooled configuration. It has already been said: The AAZ engine without an intercooler will fail in a VW bus just as quickly as the JX engine. With an intercooler, both engines should last a very long time (my 1.6 engine in a VW Golf has 460,000 km on it, the last 55,000 of which were with 1.2 bar of boost instead of 0.7). I will install the intercooler on the JX engine in the spring; it's already at home. The experiences from our other 3 cars show that it is technically a complete absurdity to run or even sell a turbocharger without an intercooler (VW is not the only manufacturer that has done this, but it is particularly problematic in the VW bus , because this poor little engine is always driven at its limit in this heavy, moving box).
In addition to reducing the engine load, increasing the boost pressure and adjusting the ESP will give you a significant power boost (approximately 100 hp for a JX engine, and 120 hp for an AAZ engine). Registration is then straightforward if you have a truck or if the vehicle is still classified as emission class 0 due to its age. In that case, you don't need the expensive emissions test; you only need a power test. Uwe from the Bulliforum might be able to provide more information on this, as I don't know the details anymore about what was originally installed in these older vehicles.
Oil cooler: It is generally recommended for the TD, but if you, like me, rarely drive the bus faster than 110 km/h (e.g., considering fuel consumption), it is not necessary. However, even at 110 km/h, you will still encounter inclines in the Kassel region .


Best regards, Uli.

Hello Uli,
Thank you very much for your detailed information!
'100 horsepower from a JX thanks to a turbocharger sounds great. I'll suggest it to a friend who just got a new JX (also a Westfalia with a high roof).'
Can you recommend a small language model that is inexpensive and relatively easy to install?
Regards,
Sausage blinkers.

Hello,

Wurstblinker wrote:

Can you recommend a small language model that is inexpensive and relatively easy to install?

"Actually, there are no limits to your imagination. I buy this kind of stuff on iiibääh. In my Passat 32b, I have one from a Nissan 200zx (or something like that), and for the bus, I'm using one from a C-Class Mercedes; it's nice and flat. I still need to build a bracket for it and attach it somewhere on the underbody (ideally in the airflow, but not exactly at the lowest point...). I'm not sure where I'll get the pipes/hoses from yet; the stuff from tuning accessories is too expensive for me. Probably something from the heating, ventilation, or gas-water-stuff area ."
If you don't enjoy improvising, there are ready-made sets available from specialized suppliers (like Papmahl), but they come at a cost.

Best regards, Uli.

Hey Uli, maybe I can't describe it perfectly in technical terms. What I mean is that the turbo (specifically the wastegate) regulates the pressure directly after the turbo, setting a boost pressure value (e.g., 0.7 bar). Without an intercooler, this pressure value goes directly into the engine. With an intercooler, it's different because the cooling process allows for more air, which needs to be replenished. However, since the turbo is still producing 0.7 bar (followed by a long pipe to the intercooler, the intercooler itself, and then another long pipe back to the intake manifold), the friction, air flow, cross-section, and other factors prevent this from being immediately compensated for. As a result, the boost pressure at the engine (e.g., measured by a boost gauge at the intake manifold) will not be the full 0.7 bar. This effect can also be counteracted with this boost pressure increase.

That's roughly what was meant; please correct me if anything is still wrong.