Engine/Transmission (1994 - 1998) Trubo bark and air filters

[Big D.Wayman]

Turbo bark (compressor surge) has been well defined here over the years, but I haven't found much talk as to how air filters effect it.



To simplify, I'll say turbo bark is the turbo equaling pressure differences. Right after I installed an HX-40 turbo and additional fuel increases, my turbo bark was really bad with the stock air box and filter. Within two days, I changed to a BHAF and I swear turbo bark was significantly reduced. Why?



I feel that the air filter effects turbo bark like a bottle neck. Increase air flow through the filter and the turbo equalizes pressure differences more easily (not as loud/violent).



I bring this up because I'd like to upgrade to a cold air intake that uses the stock air box but I really don't want that turbo bark back.



Who else has experiences with reduced turbo bark dependent on air filter setup? Am I way off here?

 

[CumminsPower98]

Turbo bark

I am running somewhere over 300 RWHP and started out using the K&N in the stock box and could get some turbo bark if I let up quick to shift under high boost. Since I went to the BHAF I have not had one turbo bark so air filters do indeed make a difference. I feel that a more freely flowing filter reduces the vacuum on the intake side of the turbo thus making it harder for the air to rush back the wrong way.

 

[Extreme1]

I think the reason you don't hear it as much with the BHAF (especially compared to a K&N) is only because of the BHAF's ability to silence noise better.

 

[illflem]

I'm with Extreme, think it's there all the time just the same, some filters just allow you to hear it better.

 

[Big D.Wayman]

But does the BHAF suppress noise better than a stock air box? I wouldn't think so.



Any comparisons from folks with the silencer ring removed - is it louder with a stock air box or a BHAF?

 

[Smokin Dodge]

Bark

Its definitly louder with the BHAF that is why I went with it, not only is the whistle louder but the turbo itself is louder.

 

[CumminsPower98]

I felt like the noise level was about the same on mine when I went from the stock box with K&N to the BHAF (silencer ring removed). I don't think the filter muffles it so much that I couldn't hear a bark if there was one. My cousin went from a paper filter in the stock box to the BHAF and had the same experience as me, less or no turbo bark. So I still think that filters make a difference from my own experiences.

 

[DBrickel]

Hi ya-all. I am new to the site but have enjoyed it flipping through.

I had a K&N filter (in Stock box) and switched to an AFE. A local

diesel shop where Iget my work done Told me the bark was from the wastegate dumping. I notice it a lot with the AFE.

 

[MDKram]

I found the bark was loudest with the BHAF and much quieter with the Scotty II running in silent mode. Marc

 

[zack_76401]

why dont you just block off the wastegate then listen to the howl?

 

[Big D.Wayman]

So from the replies, I'm concluding that the BHAF suppresses less noise than the stock box. Then I'll make the jump that more noise equals less restriction and a less restrictive air filter decreases the violence of turbo bark.



In my experience turbo bark with the stock air box delivers a sharp whoof, whoof, whoof sound but turbo bark with a BHAF sounds more like one constant sucking air sound - whooosh - less violent in my opinion.



So I need to figure out how to get the cold air intake setup while keeping a BHAF or other large volume air filter - the whole goal of which is to further decrease EGT's.



Thanks everyone for their input.

 

[98rammer]

i have a k&n in the open. i've never barked the turbo, but i do get the whoosh-whoosh. i've noticed that it's not that pronounced with the silencer ring in, but when i pull it out, the whoosh-woosh is a lot louder and i can see the pressure differences on my boost guage.



Tom

 

[zack_76401]

man ive ran mine like this for over 100K miles---no probs so get your panties out of a wad and run that dog... ...

 

[illflem]

Zack, I don't think anyone is saying there's a problem, they just want to know which filters bark more.