I have a 2003 A4 1.8t tip.

When I accelerate, and then let off the gas, i can hear a faint - not sure how to describe the sound - kind of like a breathing sound - like the engine's letting some air out or something - kind of a whoosh sound - but it's faint. I've had the car for 2 weeks now, and never noticed it before. Also, last night, i put in a K&N filter - so maybe that has something to do with it - or maybe i just never noticed the sound before.

Does this sound normal?

 

I dont have the 1.8T but I'm guessing that is your DV (Diverter Valve) which would be comletely normal.

I'm sure one of the turbo guys will chime in to confirm...

 

Yes its your Diverter Valve. It makes a Whoosh sound when you let off the gas but you usaully cant hear it with a stock airbox. Sinc you put in a highflow air filter you are gonna be taking in more air so it will be more audible. I have an intake on my car and when I let off the gas I hear a loud psshhhh I also have a chip though and that helps with the sound but yeah the sounds is normal I actually think its cool

 

Yes, since you changed your filter out its letting the air breath better so thats prolly the small whoosh sound you can just barely hear when letting off the gas... Its alot more noticable with a ko4 (Id assume) or with a different cars turbo, since they can blow the air off.... If you get an exhaust you'll be able to hear the spooling of the turbo more to, sounds normal though man

 

Phew! That's a relief. Thanks for the info.

 

Yeah, if you get an intake and a diverter valve it will become alot more audiable..I like the sound personally, you plan on modding your car?

 

I'm still under warranty for another 6 months. After that, I plan on doing the DV and a chip. I've read here that REVO is best for the B6, but I only have GIAC and APR nearby, so I'll probably go with GIAC.

I've thought about doing the injectors as well, but I don't want to have to do a whole bunch of other mods (exhaust, FMIC, etc.). Also, I have a tiptronic, so I think there's a limit to how far i can push it. Also, would the new exhaust cause me to fail my annual emmissions test?

I'm also not that mechanically inclinced - replacing the air filter was enough of a pain in the ****! [:@]

If I could do just the injectors, chip, DV without having to do anything else, and still be reliable, I'd do that, but as of yet, I'm not sure that's feasible.

 

There is a limit but you can just get a level 10 tranny and you'll be alright. If you are not gonna go HUGE you can keep it the way it is. You need the level 10 tranny to do the aggresive files if you get a K04 or if you get a GT28RS period.

 

Not a level10 tranny, level10 tranny upgrade (only certain components are upgraded in your tranny) like valve body, torque converter. You dont need a level 10 upgrade with an aggressive k04 file unless you are front trac tip. The quattro tiptronic can handle up to 310 ft lbs. Unfortunately the the tiptronic front trac can only hold something like 235 ft lbs. That info is from ZF's website.

The dv isnt louder because you are sucking in more air, its louder because a higher flowing intake/filter opens things up more to echo. The sound the dv makes when you let off the gas is boosted air being sent back into the intake ducting and a higher flowing filter allows the sound to be less muffled.