[whitebullet3]

if your saying your hearing a noise when you let off real fast, that's known as "turbo bark" and whats happening is you have all this exhaust energy driving the turbo. That in turn has the compressor wheel compressing air and sending it through the intercooler and then into the engine. When you let off the throttle quickly you no longer have the exhaust energy driving the turbo, but you have all that pressurized air on the compressor side. It is looking for the easiest way out. The easiest way out isn't to continue on through the intercooler and to the engine, but to try and come back through the turbo. This causes the compressor wheel to slow dramatically which can hurt either the wheel or the shaft if its done over and over.

 

[pepsi71ocean]

im not sure if a cone filter would cause it unless it has a low CFM rating, the BHAF mod is well known around here, but then again these filters are rated for ~680cfm.


The stock airbox is rated for more, but the input hole for the stock airbox is rated much lower and causes the restriction.

 

[pitman]

How do I fix the bark

 

[drunk on diesel]

I would take the crappy filter off and put a real one on there, but you have to realize, the turbo is probably doing the same thing it's been doing all along, you just couldn't hear it before

 

[Joe Mc]

How do I fix the bark

Stop letting out of the go pedal so fast. :rof


Sorry, Couldn't resist. It takes a bit of practice to "ease-out" of the go pedal, but it'll help your turbo last. Practice, practice and practice some more.:blues:

 

[KATOOM]

if your saying your hearing a noise when you let off real fast, that's known as "turbo bark" and whats happening is you have all this exhaust energy driving the turbo. That in turn has the compressor wheel compressing air and sending it through the intercooler and then into the engine. When you let off the throttle quickly you no longer have the exhaust energy driving the turbo, but you have all that pressurized air on the compressor side. It is looking for the easiest way out. The easiest way out isn't to continue on through the intercooler and to the engine, but to try and come back through the turbo. This causes the compressor wheel to slow dramatically which can hurt either the wheel or the shaft if its done over and over.

This is exactly right IF you're post is about barking. If you're simply hearing a howling whirling sound upon letting off the throttle at higher boost pressures then you're fine. Barking is bad and can cause the turbo shaft to break which is why guys who push real high boost have been known to set up pop off valves like turbo gas engines.