Silencer Ring.....or is it?

[BigGunZ]

Gunz: that gap that is the result of removing the SR has the abiity to restrict flow, however that is in the instance of the air being PUSHED into the turbo (which by all acounts does not happen, no matter what the "Ram Air" manufacturers what us to think). This gap is like a wall against the aerodynamics, think the tailgate of your pickup. In effect, the air is not pushed into the turbo unless we are going REALLY fast and the turbo has no spool, however when we are using the turbo (making it sing so to speak, producing power) it is PULLING air into itself, a volume smaller than the intake tube, therefore the wall does'nt have an significant effects on the air entering the turbo. Heck, I'm almost convinced that even if the air was pushed into the turbo it would have minimal effects, as the trapped air in that "wall" or "gap" created would simply BE trapped and make an aerodynamic "ramp" int the cylinder by the trapped air.

Keep in mind, this is all in theory of what I've learned in my university physics class (about 5 years ago), so I have no physical readings or evidence to back it up. So if anyone else here an either support this theory or disprove, you're more than welcome! The real world results always put theory back in its place in the end...

I see what you're getting at but the air doesn't have to be pushed through mouth of the turbo by a ram effect for there to be a movement of air through the intake tube. Bernoulli's Principle applies to air acting on a convergent/divergent duct regardless of whether the air column is moving due to pressure or vacuum. My initial impression is that the cavity created by removal of the ring is just a hollow space. A space that is exposed to the moving air column, and a space that is not uniform in shape. If isolating that space from the moving air was their goal, I find it odd that they'd choose an apparent convergent duct design.

 

[Tink]

Aside from the cool sounds they make, why do we spend big bucks on aftermarket exhaust systems? Because they reduce flow restrictions, right? How do they do this? Larger diameter pipe is one component - it has less flow restriction, and removing or reducing bends and sharp geometric transitions - this reduces turbulence and therefore flow restriction, is another component. The induction is similar, as it also is a fluid flow system and follows the same laws of fluid flow. If the ring is taken out, the transition between the inlet tube and the turbine inlet becomes a 90 degree transition - bad for flow. With the ring in place the flow sees a gradual transition from the large diameter of the inlet to the small diameter of the turbine opening - better for flow. In this case, with the ring the turbulence is reduced. Reduced turbulence = less vortex formation, therefore less whistle.

 

[jjohn]

Holset calls it an inlet Baffle

http://www.holset.co. uk/files/4_4_1-service%20repair%20manuals.php

 

[JVolpe]

http://www.holset.co. uk/files/4_4_1-service%20repair%20manuals.php

Well that should clear up everything, now let me look at the definition of baffle:



baf·fle (bfl)

tr. v. baf·fled, baf·fling, baf·fles

1. To frustrate or check (a person) as by confusing or perplexing; stymie.

2. To impede the force or movement of.

n.

1. A usually static device that regulates the flow of a fluid or light.

2. A partition that prevents interference between sound waves in a loudspeaker.



As a verb it is to impede the force or movement.



As a noun it is to regulate the flow or prevent interference between sound waves.



So it is whatever you want it to be seems to me.

 

[jjohn]

http://www.holset.co. uk/files/2_1_1_2-HX35.php



Ok I'll do the work for you...

look under Optional Features it says >> "Sound suppression baffles".

JJ

 

[BigGunZ]

Awesome. Those are great books. They do appear to be "technician level" publications though. In other words, a component's name in the publication, doesn't necessarily imply it's function.
Irregardless of that though... I know with certainty, that a turbo compressor will perform measurably better, i. e... it will generate more flow, consuming less energy, generating less heat, if the air charge impacting the compressor blades is controlled, through properly shaped ductwork and/or flow straighteners. Essentially, removing the silencer ring, regardless of it’s “purposeful” or “accidental” design, will negatively impact the performance of the compressor. While a minor phenomenon at the turbo outlet, it’s a major factor when considering the displacement multiplication of a forced induction engine (theoretical displacement). If we could examine two otherwise identical engines... . One with a SR, one without... we should see a difference in the torque curves on a dyno run (engine dyno only). Not in peak HP. Not in peak TQ. The difference will be visible in the power available “under the curve”.

 

[Nate]

With the silicener ring removed, I don't think there is any different in turbo noise. I still can just barely hear it over the exhuast.

 

[Pourinthecoal]

Whether it does or not, I won't notice it driving everyday.

 

[KClay]

One sure fired way to find out if it has a use is to check your pyrometer. If by removing the white veins in the bend of the air pipe effects the air flow then of course your egt will go up. So far mine has not. And as for the ring ... ..... Hmmmmmmmmm lets see, Dodge was told to quiet their engine down because of two reasons. 1st reason FORD... 2nd reason CHEVROLET. They just couldn't stand the fact that not only is the cummins a more powerful engine but it sounds like a true diesel should sound. So I will keep my ring and my baffles off my truck revvv my real diesel and watch ford and chevy owners drool and try to keep up. Oo. Oo. Oo. Oo.