B-Peterson

Does anyone know what causes the popping sound under load, over 30lbs boost, while shifting? Mods include stage 2 injectors and Edge EZ box, 4" turbo back exhaust, K&N, stock air box. Can it be corrected?

Rammin On

Tis called barking .... happens when the boost has no where to go .... kinda sounds like whoof whoof ... huh?

phox_mulder

And it's not good for the turbo.

Basically the air going backwards through the turbo.
Causing it to momentarily either slow down, or stop.

Best way to prevent it, is slow releases of the go pedal.
Or, avoid shifting at WOT.

phox

B-Peterson

Correct! What is the actual cause and the solution? Cousin has Powerstroke that does not do it.<br><br>Brett

Rammin On

I didn't say it was good .... but it happens .... and the H1C and HX35's can take a heck of alot more than the HX40's can .... I've been &quot;barking&quot; mine for close to 150K ....

phox_mulder

The turbo is pressurizing air in the intake.<br><br>You release the accelerator suddenly, and the turbo slows down due to less exhaust gasses spinning it.<br><br>Since the intake is pressurized, the air wants out the quickest way possible, and the turbo is no longer applying pressure, so the air goes out backwards.<br><br><br>I'm guessing since you have an EZ, you have the wastgate either blocked completely, or at least restricted, therefore you are able to build 30#, normally the wastegate wouldn't let it build up that much, and there wouldn't be enough pressure to bark the turbo.<br><br>See my previous post for preventative anti barking measures.<br><br>Not sure why the powerstroke doesn't bark it.<br>Probably wastegate related, or different turbo?<br><br>phox

B-Peterson

Thanks Phox for the info. Would an upgrade in the airbox solve the problem - say cutting holes in it or Scotty replacement?

phox_mulder

I thinking it wouldn't.<br><br>A bigger turbo might help though.<br><br><br>phox<br><br>

chuck3

My turbo would never bark before, even with EZ and DD1's, but I could only get 28 psi on the boost gauge. I got a different elbow with smaller hole and now get 32 psi + and yes now it barks big time.<br> If you don't want it to bark lower your boost a little. ;D

dodgeram

would a blow off valve help stop the barking ???<br><br>I know on a gas engine it's set just above max boost pressure and when you let off the throttle real fast and the throttle plate closes the pressure spikes the BOV vents ........ kind of like a pressure release valve<br><br>I've never seen one on a diesel though ??<br><br>

VinDiesel

My thought (for what it's worth) is that the blowoff valve would never operate. The diesel doesn't have any throttle plate (butterfly), so the pressure won't necessarily exceed maximum boost, but is more than the engine can take at that moment.

Mine has been barking also since I installed the 3K GSK. I plan on setting my WOT shift points a little higher, have already turned down my boost controller some, and am going to a 14cm2 turbine housing.

I also wonder if modifying the air box might help a bit- seems that if you are pulling a bit of a vacuum, it would aggravate the problem. A nice duct from the cowl can add some cool air and reduce restriction (at the price of more turbo noise). Of course at some point depending on power upgrades, a person will probably decide to loose the stock box.

dodgeram

there's no throttle blades ??<br><br>I guess that's why you never see a blow off valve on a diesel then, cause yeah there'd be no pressure spike .....<br><br>well that answers that question for me, thanks

VinDiesel

Yeah, engine speed is solely dependent upon the amount of fuel being delivered. Air is only limited by cylinder volume and rpm (not counting a few small restrictions here and there).

Homestead

I have an EZ on my truck and I can only make 22 psi of boost. I have the boost elbow installed and everything. Is this right or should I be looking for a problem. All the charge air hoses are fine and to the best of my knowledge, nothing leaks.

Rammin On

You can make any stock setup bark the turbo ... yup you can .... any takers?