Boost Gauge-----Is this normal?

[JEly]

I just put gauges and did the Bomber Lite turbo and now I am wondering if this is normal for the boost gauge to do when I get on it---------not WOT-----when it shifts I see the boost gauge drop off which I'm sure is normal but it seems like when it goes to OD then the gauge really drops off and bounces and this afternoon I noticed when it did it something sounded as if it snapped shut or closed and the boost was only 28 or so when I was in it--------hard to hear with the radio on and windows open. I havent tried to duplicate yet I am wondering if I am hearing something or this normal.





Thanks

JIM

 

[RankRam]

Sounds normal, mine has done this from the get go.



I have 17,000 miles and she's running great.

 

[Bertram65]

My gauge has never bounced, it goes up quickly and smoothly to about 24lbs it drops much faster but it has never bounced around or made any noises other than turbo wistle, my truck is stock so perhaps this is normal for the turbo you are using?

 

[rbattelle]

Mine behaves like Bert's. Very smooth, never bouncing. My gauge does make noise, though. Many others have the same noise, which can be cured using a snubber (instead of an ordinary 1/8 npt compression fitting). I don't mind the noise... tells me when I'm building boost and when I've hit maximum without having to glance down. I do think yours is normal, even if it does "bounce" a little.

 

[JEly]

Thanks------I'm not sure what a "snubber" is though



JIM

 

[bmoeller]

Needle valve or some other way of restricting the flow somewhat to the gauge to prevent pulsating movement. Helps get a steady reading, instead of jumping around.

 

[rbattelle]

An example of a snubber would be Swagelok part number B-4-SA-EA. Go to www.swagelok.com and search on that part number.

 

[Jeff_K]

you're barking the turbo. Its normal. It happens quite often with autos when you are hard on it and it shifts gears. Can do the same thing with my 6speed by just letting off the throttle too fast when the boost is above 25psi in 4th,5th & 6th.

 

[JRG]

If a turbo barks when new is there any reason why it would go away/stop after a few 1000 miles?



JRG

 

[Greg Boardman-RIP]

My bomber lite made my guage vibrate. Also barked real bad and Piers said to remove the silencer ring. Barking is almost impossible after removal.

 

[JEly]

Is this barking bad on the turbo or other parts of the system? I am new to diesels so I have never heard of this term------My gauge doesnt vibrate at all I just noticed the one time the "barking" and needle jumping when it shifted to OD. How does taking the silencer ring out take care of the problem? I will say I had the torque tube on and switched back to the stock stuff last night--------did not like the way the truck sounded with the TT on



JIM

 

[rbattelle]

I don't know why removing the silencer ring stops turbo bark... first time I ever heard that.



Bark occurs when you've got high pressure in your intake manifold, and the energy output of the engine suddenly drops (as when you quickly release the throttle from near 100%, or if the transmission suddenly shifts and drops engine RPM rapidly). The turbo no longer has enough energy to pump air into the manifold, and the flow actually reverses. This results in a sudden stopping (or slowing, at least) of the turbo and the "bark".



As far as I've been lead to believe, this is very harmful to the turbo (severe bark can apparently snap the turbo shaft!). It seems to be a pretty common complaint on 48re trucks, so maybe Dodge designed the transmission to shift too sharply?

 

[JEly]

I didnt have this reaction when I had the stock turbo on the truck-----I did try WOT with the stock turbo and no problems at all. I am kinda reserved about getting on it hard if this is what's happening to the turbo. I know with the paperwork from Piers say to ease out of the throttle and maybe this is the reason but the stocker didnt do it. Also what is stock max boost-------Piers say dont go over 36# with the b-lite is this what the stock turbo was rated at



JIM

 

[rbattelle]

For a stock 2003 HO engine, maximum boost is 23-25 psi. That's been confirmed by a number of other 3rd gen owners, so I think it's a good number.



I assume the reason the Piers turbo barks more than the stocker is that it's a more responsive turbo. I'm not familiar enough with it to say any more than that. In my opinion, Piers is a great company with whom I've done business in the past... if you call and ask them about it, I'm sure they can advise you...

 

[JEly]

I agree------with the short dealings I have had with Piers they always answer my questions and I'm sure they will on this as well------------I will call tomorrow for sure



JIM

 

[JRG]

I think over 30-35 lbs will set a code?



JRG

 

[Greg Boardman-RIP]

The reason the turbo barks a little easier than the stocker is because of the amount of air being compressed by the HX40 wheel. I have no idea why the silencer ring removal stopped the barking but it worked. I was running an EZ and DDIII's with the turbo and when the fuel hit it was 36 PSI instantly. If I let off a litte to contro EGT's It would bark while accelerating with that much fuel. Piers said to pull the silencer ring to see if that would help.



JEly,

Barking the turbo is when you are under boost and you let off. The pressure created by the compressor side of the turbo is no longer greater than the exhaust side. That makes the turbo try to spin backwards. You will get a sound of a woof woof woof. Not good. The next sound is what we call Huffing a turbo. Can you say $$$$$$$$ new turbo... ... Barking can be harmful to your turbos health.