turbo bark is when you have boost and let off the throttle really quick and you hear a whooosh whhoooosh whoooooosh sound. that is air going back through your turbo in opposite direction causing the compressor wheel to turn the other way . so your turbo is spinnin at say 15 thousand rpms and with in less than a second, it is forced to spin the other way. the blow off valve solves that by dumping the boost outside rather than back through the turbo. like stated above, on stock to slightly modded trucks i dont think its really needed, even on highly modded trucks with $$$$ turbos, you dont REALLY need it but a good anology would be doing alot of boost and riskin it without headstuds. you dont really really need it but you could be really sorry if you dont have it. not sayin alot of people have broken shafts and such from turbo bark, its just extra safetly that you wont break anythign from turbo bark. hope this helps.

 

what fuel pressure are you reading on your gauges??? dont have a clue how turbo bark could blow air into the injectors and stall the motor. maybe when you are on it hard, you are using up what little fuel you have being supplied and therefore stalling the engine. fill in your sig...

 

i have never heard of that before but i could be wrong. only time i have heard of loss of injector prime is when you run it dry out of fuel. i have done that a few times in the past with my DRAG comp, get on it hard and let out to fast and it would run dry and i would have to crack the injector to bleed it to get it to start but thats a fuel thing, not so much an air thing. never heard of that before.

 

are you thinking of a manual boost controller?? a ball and spring design to limit the amount of boost your engine will see???

thats what i made for my truck and all the parts are from a hardware store...

edit: it wont make the sound you want though...

 

Kitchen - I'm sure you're turbo(s) isn't pressurizing your injectors into a reverse-flow condition and causing them to lose prime!

That would be akin to expecting the water pump to operate the HydroBoost system.

 

It sounds to me like your engine is hydro locking. I've had it happen. Once it happened real bad and it made the engine sound like it had no compression. I let off the throttle fast and it sucked the fuel out of the injectors and the IP. It happens if you aren't careful. When I'm racing or have to let off real fast I "blip" the throttle to keep fuel going to it.

 

The turbo shaft does not reverse direction in a 'bark'.

This discussion has be had before on here and beat to death.

Persistent wive's tales just live forever, I suppose.

Let's not let the facts get in the way of a good marketing campaign...


Whatever, I'm done.



Kp

 

600 MW is correct, the turbo will not ever reverse direction. Even though there is no longer throttle input, exhaust is still driving the turbo. The turbo will never turn the other direction, or even stop during "turbo bark". A better term for this is compressor surge/stall, a straightforward expulsion of air out the intake due to the compressor's inability to maintain pressure on the combustion chamber.

 

Good one, J.R. !

Now what's up with this hydrolocking?

 

Pgilles, the sound I'm talking about is a loud whoosh of air that happens when you upshift from gear to gear. I believe there's a air release valve(like an air compressor part) that can be put in but I don't know what its called or where to install it. I'm hoping someone has this & can give me some info.

 

that sound is the nature of the beast, no release valves or whatnot needed. driving easy you wont hear it as you are running with near zero boost. drive harder/faster and build the boost than hang your shifts more (take a little more time going from one gear to the other) and you should hear it.

 

please enlighten me then. if the shaft never stalls or turns in the opposite direction then what in the world makes it go whooosh whoooosh whoooosh? of course i no air comes back out the filter side and your saying while the air does this it does not stop the turbo shaft from spinning becuase its always being driven by the exhuast right? well it only happens for a split second so is it possible for the exhaust side to stop as well? not trying to be a smart ..... but just trying to figure it out what causes the sound if the shaft does not stop or reverse.

 

I would have to say the woosh is coming from the air hitting the turbo blades the wrong, and also that air is under a lot of pressure. The air going into the turbo is not under pressure thats why its not very loud, but when you make 40 or 50 psi of air come back wards threw the turbo blades that are designed to move air the other way its gonna make some kind of noise. Its kinda like filling a tire, its quite goin in but if it comes back out its loud.

 

agreed but i dont see how its possible when a turbo is spinning at thousands of rpms , dont know how many for sure and then like you said, 50 or 60psi coming back through it the wrong way? it has to stop or stall the shaft.

 

No, it doesn't have to stop or reverse the shaft; the impeller is not a positive-displacement pump...