golfstrom

I'm not a TT owner but I was at the NY auto show and saw how the windows open a little upon door opening and then closes automatically.

I'm really baffled by this, can you guys explain to me what this feature is for? Thanks!

Tony

HACK THS

and the lip of the roof that comes (slightly) over the door.

golfstrom

hey thanks, that proves my friend incorrect, he was telling me something about it might be vacuumized inside and make it easier to open the doors...

HACK THS

but close the latch of the coupe with someone (or multiple people) inside and you will usally have to pop your ears. It is a neat thing to show/feel

smallTTs

Most cars have some sort of passive pressure relief valve, but this system, although complicated, is the most effective I have ever seen. It prevents trapping air as the door closes.
Even 1/50 of a psi differential would cause an extra 30+ lbs. force trying to hold the door open.

Actually the glass doesn't move down until the door pops off the latched position. Glass doesn't appear to get 'trapped' in the upper seal even if there is no motion. If it were required to move in order to work, you could damage it with a disconnected/dead battery. That's not something a designer would allow.

This is one of the small, subtle things that makes the TT such a fine car. Besides, look how impressed non-TT'ers are with this and the aliens!


My $.02

42N8 TT

Think about this:

Which is more important, not having to "slam" the door, or protecting the occupant(s)' eardrums from overpressure when the door closes?

Engineering pressure resistance on the glass or seals is important, but they are much more elastic and durable than eardurms, and routinely survive such stress (e.g., fan set to max output.) On the other hand, having one's eardrums "pop" when the doors close is generally not a desired effect. If you *want* to try this, sit in the TT with the doors closed and the hatch open; have someone gently lower the hatch, then close it firmly. You will notice the overpressure!

Audi specifically designed the window feature because of the TT's relatively small cabin (in which overpressure more easily occurs than in, say, a large sedan) and the efficiency of the window/door/hatch seals. (BTW, the same effect occurs in light aircraft with pressureized cabins.) HTH. Cheers!

smallTTs

and the system is vented to the outside.

Closing a door or hatch just moves more air quickly than can be handled by the other venting, so the window dip is just a elegant, but active, rather than passive, solution. No additional overpressure vents are required, so when you close the hatch you feel the o/p.

On a C5 Corvette closing the hatch with doors and windows closed requires a mild slam. I wish it had the TT system.

FWIW, window seals need to keep air/water from getting in at times and to keep the windows from sucking out (on some body styles) at higher speeds. It's a design challenge met better by some than others. IMO, TT is exceptional in this respect.

Audi did eliminate this on the roadster, didn't they? So what happens if you get the 'hardtop' accessory?

BillK

The problem with frameless windows is always that the motion of the door is such that you will never achieve as good a seal with the window stationary as you do if you lower it and raise it.

I had an '89 Ford Probe, and it too had framless windows and had this very problem. You would get wind noise if you just got into the car and closed the door, but you could eliminate it by rolling the window down a bit then back up after you got in.

Audi's "automated" method of doing this just assures the best window/frame seal possible with the frameless windows...