Setting up the VNT on a 110 AFN Passat.

[K2edg]

Hi all.

This is more out of curiosity than anything else, i fitted a fresh Melett GT1749V 454231 CHRA to my turbo as i had noticed the bearings weeping a little too much oil last time i stripped and de-carboned the VNT vanes etc.

So when i fitted the new core i spent a bit of time to make sure things like the VNT leaver was in the same position and had been welded with the arms on each side in the same position as the original etc (which they were), on a bench i tested the VNT worked ok by using a mityvac to operate the vanes (it started to move at about 3mmHg and just touches the stop screw at 18mmhg which i believe is correct??)

Now i'm not sure if it was because the VNT had started to stick and over boost but when i reassembled it with fresh gaskets etc it ran great but i thought it felt slower but smoother (if that makes sense) so i did a fair bit of searching and reading up which brought me to this thread https://uk-mkivs.net/topic/34834-vnt-td ... -problems/

So i borrowed VCDS and ran the test (Measuring Block 011 at 4000rpm full throttle in third gear) and i found my duty was early 60% (would fluctuate from 60-64 on different runs) so as it says in the thread i marked then adjusted the rod to get it between 70-80%, although it felt quicker a knock on effect of shortening the rod was it had moved the VNT leaver off the stop screw which meant it took longer to spool up.

Now i'm not sure if the different versions of TDI (110hp, 130hp and 150hp) and if all use the same fuel system, so i'm trying to set up my 110hp to another hp engines spec? or i have an issue...... Might be as simple as my car doesn't work in the same way as a golf tdi and i'm trying to fix a problem that isn't there.

I just thought i'd ask to see if anyone out there was clued up on setting the VNT this way.

Cheers.