1.8T 20V non VVT head to VVT conversion

[sambb]

So I'm going with large port AGU head for my Polo's 1.8T build. Given that its large port and also that I wont be using a huge sized turbo, I'm pretty keen to convert this head over to VVT operation. The aim of this is not just for the VW cold starts but to use intake advance throughout the rev range to boost off boost running and spool up. Yes I'm aware its an on/off system (not infinitely adjustable) but that didnt stop Audi using it this way and I want to do the same.
Now looking into this and reading up on other people who have done this it seems apparent that the VVT system moves the cam a total of 20 crank degrees - so 10 cam degrees. ie 20 crank degrees advanced from its setpoint at cold start (and between 2000 and 4800rpm in Audis) and then retards back to setpoint (displayed as 0 degrees) for the top end. You can see this in blocks 091 and 094 in VCDS - actively in an Audi, only at stone cold start in a Polo BJX.

But people have have fitted the VVT tensioner/solenoid assembly to the non VVT head and have noticed that the inlet cam will then sit 4 crank degrees retarded (2 degrees cam) compared to where it had been with its initial fixed phasing non VVT tensioner. So once VVT is operating on the previously non VVT head, the cam position range shows as 16 degrees advance to -4 degrees retarded. The same 20 degree range but shifted/retarded back by 4 degrees. Several people who did the change noticed this and put up logs of their cam vs crank triggers before and after to show this, so I was wondering if anyone else out there has noted this OR if anyone who has done the VVT conversion to a previously non-VVT head can look in their VCDS to see what cam position numbers it is displaying? - 20 to 0 degrees or 16 to -4 degrees or thereabouts in block 091.
Actually if anyone has a non VVT AGU that is running stock without a VVT conversion, any chance you could do the same (if your version of VCDS/ECU will allow it) to see what your fixed angle is?
And the other side of the story is WHY would this be happening. If the cams are the same and the tensioner chain is the same (which is what I suspect) then it could only be the ranges of the VVT tensioner mech itself that causes it yeah? I've tried to find the part numbers of the inlet cams between VVT and non-VVT heads to see if the cams are the same. Lots of manufacturers have different VVT to non-VVT cams so I guess its possible that the profiles could be identical but the chain sprocket is keyed differently or even that the cam position 4 window flag is pressed on in a different position? Profiles could be different even, not sure?
Either way if I choose to run fixed cam timing NON-VVT or with VVT I think it'll be very important to get a tune tailored for that as I cant see how you could fit a non VVT head to a VVT car/ECU withy the solenoid unplugged and expect it to run great because the cam would be then 4 degrees advanced compared to what all the maps are expecting.

[lynx]

I'm pretty keen to convert my non-VVT head over to VVT operation.

My aim of this is to use intake advance throughout the rev range to boost off boost running and spool up.
Yes I'm aware its an ON/OFF system (not infinitely adjustable) but that didn't stop Audi using it this way
and I want to do the same.

Now looking into this and reading that the VVT system moves
the cam a total of 20° crank degrees - so 10° cam degrees.
ie 20° crank degrees advanced from its set point at cold start (and between 2000-4800 Rpm in Audi's)
and then retards back to set point (displayed as 0° degrees) for the top end.
You can see this in blocks 091 and 094 in VCDS - actively in an Audi.

The above information about the function on VVT equipped 1.8T 20v engines was very informative to me.
Do you ( sambb ) or anyone else here on the forum know more details ?
I would really like to understand how the system works.
( I have a really hard time finding information about this VVT system despite actively searching )

I have a 1.8T ( 20 v. ) engine with VVT
ECM: BOSCH Motronic ME7.5

I randomly keep getting the below fault code on the VVT-system when I check with VCDS.

16395 - Bank 1: Camshaft A ( Intake )
P0011 - 002 - Retard Setpoint not Reached ( Over-Advanced )

I don't have any mechanical noise or slamming/rattling from the head/chain.
I have opened the valve cover to check the chain and everything looks like new on the plastic chain sliders
and I have no oil deposits ( changes oil regularly ).

1. What does this error code mean so that one understands the meaning of it ?
2. Can someone explain in detail how the VVT system works on the 1.8T ( 20v. ) engines ( 2001-2010 ) ?
3. What happens if the VVT is closed all the time and does not regulate ?
4. What happens if the VVT is open all the time and does not regulate ?

My engine generally feels weak in the midrange and has relatively high fuel consumption.

[h100vw]

Make sure you have good oil pressure. Remove the sump and check the pick up is clean. Also take the solenoid off the tensioner, and make sure the plunger is free to move where the spring is in your photo. I had one once where there was some debris jamming it up.