RonP

Ok, I know we have opinions so I will give mine. I know its been stated many times that it isn't for anything more than making it quiet, but I noticed a drop in mileage and performance, no doubt about it. I removed it and replaced the tube with a huge open piece of tubing so I am not sure if it was one or the other but it changed for the worse and it went back to stock.
just my .02

bigblock2stroke

Not true about the airflow(the turbo speed is true 120000rpm)

A cone is a decreasing diameter tube. As the diameter of the pipe decreases you get increased pressure for a given amount of flow therby increasing the likelyhood of more turbulent flow.

You believe what you want but the silencer ring is just a silencer, not a flow improver/director/smoother.

The turning vanes are there to help "direct" the flow after the silencer.

BlackSheep5

I did not touch the "vanes" in the elbow, I left them in place.

goose2

RonP, After putting everything back to stock. What performance gains did you get? (milage, power etc.)

RonP

Call me crazy, but I could tell the difference. I am not talking about huge seat of the pants differences here, but we all know our own vehicles and can tell when something changes.
yes it came back, after removing the ring and replacing the tube, my truck just seemed to feel like it lost some pull out power and my mileage went down 1 mpg and that was repeated time and time again. I liked the sound but couldn't deal with that. To me it just feels stronger with those parts remaining factory.

ed paul

ya know,,i bet if u could put something in that silencer tube to get the air spinning in the same direction as the turbo blades u would see a power boost,,at least a faster spool-up

06Cummins

anyone tried the tornado

Duallydog

In my 305Hp removing the silencer ring makes me question the mileage and it feels like my power drops off after 2200rpm, but after removing the muffler my low end power was no longer there, and tossing the silencer ring brought back that low end grunt.

BigGunZ

You'll get the same answer...the ring does nothing. My comment stems from experience with jet engines...turbo jet engines. If you look at every available modification to the airflow system, whether intake or exhaust side, you'll notice a common thread. Reducing exhaust back pressure, reducing intake restrictions, smoothing out the intake flow with smooth tubes, porting and polishing heads, turbo housings, etc, etc are all designed to either increase the amount of boost, decrease the amount of time to build boost, decrease the time required for the air column to move from point "a" to point "b", decrease response time from the turbo.....we go through all of that trouble yet will pull the silencer ring because it's largely believed to "do nothing".

I pulled my ring out of curiosity. It really didn't increase noise any and didn't appear to hurt performance , but one thing was clear...the shape of the ring was like a velocity stack. it clearly covers a gap between the inner and outer turbo housings and funnels air into the compressor section. If you were to look at the compressor inlet of a jet engine you'd see the exact same thing...properly shaped ducting funneling air in the exact same way. The "do nothing" belief is likely rooted in the fact that most people judge performance by peak dyno numbers and largely ignore what's occuring under the curve. In other words, if the numbers don't change, we're not losing or gaining.

In the end, the compressor wheel is spinning at insane speeds, speeds that can literally stretch and distort the wheel from centrifugal and aerodynamic forces. Smooth, laminar flow does far more than reduce noise.

STATELINE

I also was considering the velocity stack design, just wonder if you had one that fit the housing & was say 4-6 inches long, might help with low-mid range torque. anyone tried that yet??

043500QC

I`m not trying to agrue your point here, but I do question why the CTD in the Dodge trucks is the only Cummins engine with the silencer ring. What your saying about smooth, laminar flow makes perfect sense to me, but if it its actually there to smooth out the flow, why isn`t Cummins using it on all their engines ?

BigGunZ

I have a TAG that incorporates a small stack. It was all that was available if you choose to run a smooth tube of some sort. It wouldn't really increase torque directly but coupled with proper flow straightening, would change low boost characteristics. For example, the compressor wheel would be more evenly loaded which reduces friction. The end result would not necessarily be more boost, but better boost...turbo would spool faster, less turbo lag, less heat generated, and snappier "feel". The end result would likely be a flatter torque curve down low and torque would build faster. That said, it's unlikely your average dyno would show this. An engine dyno likely would.

BigGunZ

Thats a valid question and the answer is likely cost verses benefit. Heck, just look at the lenghts mfgrs go to just to save 39 cents per vehicle by not giving us a drain plug for a tranny pan. Additionally, the CTD used in commercial applications use a long straight run of tubing to feed the compressor...not the tangled mess found in the Dodge.

If you were to examine any modern jet engine and look at the compressor inlet, you'd see a convergent duct design (cone or stack) coupled with flow straighteners, incorporated solely to increase compressor performance.

goose2

Well boy's there is one way to find out. I had mine off and now I put it back in. I will report any findings. (if there is any)

ed paul

while you are at it,,take the cross member out of the silencer and fill the silencer up with 1/2 tubes solder them together,,hhhmmm,,i think I"ll try that come spring,,maybe i could even bend some to fit in the lower hose,,that would make one hell of a tag,,,no jokin,,I think I"ll try it