geiswiz

I have almost 4K miles on my 225 TTQC. I just noticed a noise yesterday when relasing the gas. The noise is most apparent when I'm in 3rd gear. When I floor it and then release the gas suddenly I hear a sort of winding noise coming from the engine. The noise seems to occur only when the turbo has kicked in and then I let off the gas suddenly. I don't know if this noise has always been there, but I have never noticed it before. I usually drive with my music up pretty loud though, so maybe the noise has always been there, but I have just never noticed it. Does anyone have any insight on this? Thanks.

mad haTTer

I had the same problem a new d.v. cured all

PanTTher

The gas pedal. It's normal.

geiswiz

Can you explain to me what a d.v. is? Is it the same as a forge dv? Is this something that would be included in my Audi warranty or is it something that is not covered? Thanks.

EighTT

As you may know, I have owned 2 TTs. Both developed the "springy" sound during throttle lift. However, neither TT had this initially.

This really bugged me during my first ownership experience. So obviously, I was listening for it when I took delivery of the Roadster, but the noise wasn't there. If this was "normal", wouldn't the noise have been there all along?

I thought that the Bailey would resolve this, but it did not, though it did improve engine response. I'd like to know what's really going on here.

economisTT

presumably fixed forever with the bailey.

economisTT

so i guess i don't understand why it would work in one case and not in another.

Larrytt

It is what is causing the noise that is the problem!

Let me explain it this way. The OEM DV does not make any noise unless the diaphram is torn, then you will hear a rush of air causing the rubber diaphram to vibrate. That is the noise you heard in both of your TT's with the stock OEM DV.

The Bailey was originally inserted in the same orientation as the oem DV which everyone was soon to learn was actually 180* off from the proper way that a DV should be installed into a turbo charged car. The Bailey would make a breathing sound when you let off the gas. This was just the turbo pressure releasing back into the turbo. When you reverse the BAiley direction this sound lessened.

The reason you hear the sound more in a Bailey or a Forge DV over the OEM DV is the spring pressure and efficiency of the aftermarket pieces. Since the aftermarket parts are much better designed and implemented then the pressure release will be much more precise. The oem part would allow the air to release back into the turbo at a much lower pressure and hence it would be very quiet. The aftermarket valves are releasing the pressure back in at almost 4 times the pressure and are always releasing at the same pressure as the car was designed to do.

That was another of the problems with the OEM DV, it never released the turbo pressure at the proper pressure setting, it was always changing. Mance ran a test with the OEM DV and also a Bailey DV and found that the Bailey would release at a constant 12 in/HG, where the OEM would release all over the map, from 0-9 but never at the Audi spec of 12!

I hope that explains what you are hearing

patricklp

Seriously, if you left the forum sometime in, say, September, and just came back, you'd wonder what the hell happened. Remember those days: "all DVs, all the time?" The is the first significant thread on DVs in ages.

Guess we've all had enough of armrests and snow tires.

Bahookie

If Audi ever fixes the DV, what will we talk about? btw a Forge DV is on my Christmas list