Central Rear vents retrofit, help needed.

[Lorenzen]

Hi fans,

I have my AUDI B8 '12 for few month and decided to install rear central vents (for my kid). Bought some part from local junk jar.
https://audi.7zap.com/en/rdw/audi+a4.../8/819-819037/ parts (21 22 23).
perhaps someone did such swap and can advice me? I am not sure what to do with air mix box, should I drill some hols there, or there is some parts I need swap out?

I checked air mix box and can't see these http://i792.photobucket.com/albums/y...IMG_1150-1.jpg
flaps.
I understand it will not mix cold hot air ( at this stage) but I can't figure out how to get air going thru those pipes.

[Smac770]

There are two tiers of HVAC in the B8, lower end basis and higher end comfort. The outlets for the rear center console vents only exist on the comfort distribution box.
Notice on the parts page you linked, part 18. There's two entries, one for PR code 9AK (basis) and one for PR code 9AQ (comfort). You probably have the basis system and the D part.

Even if you swapped the D part for the E part, there's not likely to be any opening from the basis distribution box to that center port on the E part. But I can't say that for sure.

Swapping the basis distribution box for the comfort distribution box is probably not a cost effective option.
You could consider tapping the footwell tubes into the center console tube and removing the doors at the footwell tubes (the doors I assume shut when not heating so A/C doesn't go into the footwells; the basis box appears to be a single temp, single chamber setup).

[Lorenzen]

Smac770, thank you.
I found some topic on how to amend footwell tubes to distribute air to central vents as well.. but I don't like this none OEM solution, well I guest it stay as is, at least for now.

[B G 8er]

That may have been me. We chickened out and did not want to Dremel out the airbox (not knowing where it would lead us) so we just ended up splicing the new added OEM ducting that runs from the airbox through the console and out to the rear vent into the two floor vent ducts coming out on each side of the airbox. The result is that some of the air coming into the floor vents is diverted and comes out of the new added rear air vent at the back of the center console. As I mentioned, the amount of air flow is sort of low and only comes through when the airflow is set to come out of the lower vents (including the rear floor vents). It works well for heating but not so great for AC. If you read agoett's post #71 in this thread https://www.audizine.com/forum/showt...3-Rear-AC-in-P, he claims he was able to dremmel out his airbox but the flow is constant with the system, so the only way to trun off the rear would be to close the rear vent. His car was also a 13 Alroad. may be different depending on the year and model. I believe changing the air box would be extremely difficult given how buried it is under the dash.