Audi 2.5 TDI: Alternative Fuel Options

Hello everyone,

I've been wondering all the time if I could install a different turbocharger on my 2.5 TDI AEL.
To the best of my knowledge, the AEL has a K14 turbocharger with a turbine wheel diameter of 50mm.
I was thinking of installing a K16 turbocharger from the K1 series, with a 55mm turbine wheel.

I know that the response behavior is changing, but can't this be corrected with appropriately configured software?

Has anyone tried this before, or installed it themselves?
What kind of performance increase would be achieved? (I'm estimating around 200 horsepower or more.)

I know that I can only install one chip, but I'm interested in the charger.

Therefore: who has already tried it?

Regards,
Peter.

Hello,
Have you or anyone else ever tried it?
I have a brand new K16 (which probably fits in the AAT) and an AEL with a K14, but the boost pressure builds up too slowly. Can I replace this part with the larger one, or not? Looking at it, it might fit, but I haven't measured anything yet. Since removing the turbocharger is a very complicated process, I don't want to test it and then find out that it doesn't work.
Why does the more powerful engine have the smaller turbocharger?

Regards,
sat24

Hi,

The K16 turbocharger in the Audi 100 AAT was characterized by a very slow build-up of boost pressure. It doesn't produce much power below 2,200 RPM, and even above that, it takes some time to spool up.

At the time, VW/Audi had switched to smaller turbochargers in some models (including the Audi 80) to achieve earlier torque delivery.
Probably, starting in 1994, the AAT also used the K14, just like the AEL.

Data:
Audi 100 AAT (until 1994): 265 Nm at 2,250 rpm.
Audi A6 AAT (from 1994): 265 Nm at 1,900 rpm.

The difference is noticeable!

'Well, that's quite a statement. Thanks. I'll skip any further tests for now and just check the wastegate. It's a pain, how do you even get these things out of an A6? You can't reach any of the nuts with normal tools.'
And then I probably have a new K16 VW, number 046145703F, left over.

Regards,
sat24