silencer ring

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Hey CMECHANIC

Try this again, some how I bumped a key a couple of times, I guess I will be a member that much sooner.

Anyway, CMECANIC, I asked this question sometime back and no one responded, what year Dodge did they put the silencer ring on the turbo on the Cummins, I haven't seen one on my 92.

Rodney

 

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good question, the first one I saw was on a 1994/95; and i don't know if that was the original turbo, and that was just a snap-ring. To tell the truth i never really compaired years. just one day i saw one (years back), looked around and asked "what is that thing for" A lot of "i have no idea" and i looked it up in our updates and found it was a silencer ring. That,s as far is i looked into it---sorry

 

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When we talked about this before someone said this was a Dodge only thing for noise reduction. However last week I looked at a 99' Sterling truck with an ISB 215 and sure enough it had the ring in the turbo inlet just like my Dodge. I still say it looks like venturi. Maybe this is another secret that were not supposed to find out about?

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99' 2500 SLT,Quadcab,Long Bed,4x4, White/Driftwood,Agate Leather,4WAL,Auto,241HD,3. 54 Limited Slip

 

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I've looked through the '99 Service manual for the Ram, and there is no mention of a "silencer ring" at all. I tend to agree with Terry in that it has some function other than just to reduce turbo noise. Its shape would suggest a venturi or perhaps aids in compressing the air before hitting the fan blades to insure consistent pressure. I'd certainly like to find to true nature of this thing!

Craig

 

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The word from Cummins and Dodge is that it was put in place to reduce turbo whistle and serves no other purpose. It doesn't hamper or improve performance. Beleave it or not, alot of people complained about the high pitched turbo whistle. If you look at the pictures in the ads for Banks and others with polished turbo housings, you'll see the silencer ring missing. But just to be on the safe side, I put mine back in the truck. It's in the drivers door pocket.

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Steve McDaniel
98 ClubCab 12v 5spd 4. 10
97 Stratus
92 Harley Fatboy

 

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How's this for speculation:

Perhaps it reduces cavitation? Maybe the extra noise isn't just turbo whine, but the air buffeting the leading edge of the turbo fan blades?

Craig

 

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I received the same information from Cummins. The ring serves no other purpose than to silence the whine. I took it off and have been pulling my trailer all over the place. Still runs like a beast.

Jack

 

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I removed the silencer ring today and I have a few observations. I feel that the ring is indeed a venturi, because it exactly matches the turbo inlet---without it, the incomming air abruptly hits the edge of the turbo housing, which is near it's outermost edge and actually must reverse itself slightly to enter the turbo inlet. With the silencer ring in position, ALL inlet air is directed at the vanes of the turbosharger, flowing smoothly the entire time. Maybe it doesn't make a bit of difference due to the large amounts of air this engine must consume to produce the power it does. The only difference I noticed was an increased turbo whistle and I'll probably keep it this way for a while. The K&N filter I put in about 2,500 miles ago has alowed absolutely nothing to get by it and passed the "white glove test" with flying colors. The recent resonator removal increased exhaust noise somewhat, but not much. The only thing I would like to see this monster do is accelerate off the line like it does when the turbo spools up! From about 10mph on this truck is a rocket!!! Too bad we have that turbo lag! Went for a 400 mile trip last Saturday and got over 25 mpg with the cruise set at 60mph!!!! Love this truck!!! Sam

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1999 Dodge Laramie SLT QC TD 2WD auto trans long bed, LSD, HD towing and camper pkg,K&N air filter, CD player, elecric seats, bright white, chrome diamond plate tool box- all options except leather seats. I love the smell of diesel in the morning.

 

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In the interest of accuracy, a venturi is a device which will create a decrease in pressure. For instance a venturi in a gasoline carburetor will cause a drop in pressure to cause fuel to be pulled into the airstream through metering orifices. The decreaser in the airstream of the inlet air to the turbo in our trucks would have the opposite effect, in increasing pressure and velocity as it forces the same volume into a smaller space. I also believe this is beneficial to the opperation of the induction system as has been mentioned.

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98. 5,24v,3/4 ton,2wd,lsd,5sp
blue box hp enhancement

 

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Hey Porky,
I beleave if you lean over the fender far enough to look straight into the turbo, you'll see some openings around the outside of the inlet. This must be where the music comes from.

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Steve McDaniel
98 ClubCab 12v 5spd 4. 10
97 Stratus
92 Harley Fatboy

 

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HVAC...

If I'm not mistaken... (it has been years since my pilot training). . #ad

Bernoulli’s principal states...
"A volume of air moving through a venturi. . MUST Increase Velocity at the same input pressure. As velocity Increases, Pressure must decrease".

This is the reason planes fly. .

The curved Upper surface of a planes wing accelerates the velocity of the air molecules
moving over it.
This acceleration reduces the pressure over that surface.
The air flowing under the wing maintains velocity due to the wings relatively flat bottom surface.

The difference in the air PRESSURE between these two areas creates the property of LIFT. . and the plane flies.

What does this mean to us Turbo Heads??

As you stated... A venturi in a Carb. creates an area of low pressure which "Sucks" fuel into the stream of air. .

People on this page have reported MILD Boost Increases by removing this "Venturi" device. . and this observation seems to have a basis in Physics. .

The "venturi" effect is still there and will remain unless a Turbo with Exactly The Same I. D. inlet and outlet as the feeder Hose exists. . (Don't count on it, as the Darn thing would take forever to "spool up".

Whatever the True outcome is... that turbo whine still sounds so COOL.


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'99 2500 C. C. SLT,4X4, Auto, SWB, Forest Gr. /Driftwood, Tow Pkg. , Smittybilt S. S. Nerf Bars, Factory Tow Hooks, K&N, Mag-Hytech transmission, Dodge 3 Pc. Bug-Flector, 7 7/8 coats of wax. . Yes Sir That's My Baby!!