The woosh as mentioned before is the boosted air dumping back into the intake through the shroud port. The "wrug-wrug-wrug" sound of the turbo coming HARD off boost is "Compressor Surge" a HORRID thing for the turbo... Its the sound of the compressor not being able to continue to work against boost pressure and the air driving back through the turbo...

Definitions...
Axi-symmetric stall or compressor surge

Axi-symmetric stall, more commonly known as compressor surge; or pressure surge, is a complete breakdown in compression resulting in a reversal of flow and the violent expulsion of previously compressed air out through the engine intake, due to the compressor's inability to continue working against the already-compressed air behind it. The compressor either experiences conditions which exceed the limit of its pressure rise capabilities or is highly loaded such that it does not have the capacity to absorb a momentary disturbance, creating a rotational stall which can propagate in less than a second to include the entire compressor.

The compressor will recover to normal flow once the engine pressure ratio reduces to a level at which the compressor is capable of sustaining stable airflow. If, however, the conditions that induced the stall remain, the return of stable airflow will reproduce the conditions at the time of surge and the process will repeat.[1] Such a "locked-in" or self-reproducing stall is particularly dangerous, with very high levels of vibration causing accelerated engine wear and possible damage, even the total destruction of the engine.

 

I don't hear any chatter noise, but I am not sure what you mean by "barking the turbo" or how I would be doing that. The woosh sound occured today when I was accelerating into the flow of traffic with moderately heavy throttle (not stuffed to the floor) and I went for the shift at 2900 RPM. Any thoughts?

Shawn

 

Barking the turbo would be when youre really giving it throttle then all of a sudden taking your foot out of it while still in gear. Dieselweasel explained it really good in his post. Thanks for the info by the way. The compresser surge hes talking about is what im referring to as turbo bark. When your coming out of the throttle as you push the clutch in would be the "wooosh" sound i was referring to & thats not bad for the turbo i dont think. If im wrong someone please correct me. Like i said in the beginning of the thread i think the reason Im not hearing it on mine is because of an internal electronic wastegate like bobcat67 also said but i didnt know if there was a way of making it external? What exactly is the shroud port & where is it on the turbo? is it the wastegate dumping the boosted air into the shroud port to make the sound?

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Hey guys how do you attach a pic to a post? its asking me to give the url of my image & im not sure what they mean by that. sorry im definately no wiz with computers & im just tryin to put up a pic of my intake

 

So, if I were to run up to 3500 rpm or so then completly let of the throttle and a split second later put in the clutch I would get some compressor surge. Would that surge then rush into the intake manafold making the woosh sound?

Shawn

 

5spds generally dont experience turbo bark. ANY time you shift a stick you'll hear the air rushing back into the intake on these trucks.

 

I am definately not hearing it on every shift.

Shawn

 

Who does generally experience turbo bark then? My 12v i used to have that ive been referring to as making the sound was a 5 speed & it would definately compresser surge if i was wide open then let out of it. It only did it after i had all the mods on it though but after the injector pump got turned up like it did & the turbo was putting out much more i had to really watch out for the surge. Yall think maybe you could post up some sound clips of your trucks shifting gears. I really wish i had that 98 12v right now so i could post a sound clip of it because im pretty sure ive just confused people trying to describe the "woosh" sound

 

I'll try taking a video tomorrow of driving it. Generally automatics experience turbo bark. When you let off fast the trans and drivetrain are still hauling *** but the turbo is trying to cram to a stop so it barks.

A 5spd will make the wooshing noise when just casually changing gears and will REALLY woosh with the right mods and a wot run. I'll try taking cell phone videos of a casual shift and a wot shift.

 

I would think as far as the turbo barking it wouldnt matter whether its auto or manual. When you let off fast the trans & drivetrain are still hauling *** with the turbo trying to cram to a stop on a manual also as long as youre in gear right? Hopefully we can get some sound clips & figure out this woosh sound out. I may get a video of mine as well even though it wont make the sound but ill show how the turbo screams while its spooling

 

i have an 05 and took the silencer rings out and it makes the sound i think you are lookin for kinda like a blow off valve when shift gears at he right boost