silencer rings

[Yo Hoot]

Originally posted by hasselbach

I looked at mine tonight and found a few interesting things.



1. The cone or ring plate held by the snap ring that is near the turbo seems to be more of a velocity funnel-stack, rather than a silencer ring. I opted to leave mine alone. I've worked on enough flow benches to see that this baffle is more of an air straightner, and not a device to silence the turbo. The turbo OD is less than the opening of this plate, and removing it looks like you will introduce turbulence near the entry funnel of the blades.

2. The air tube that Hoot and others show cutting the lips off at each end appears not to be required. The hoses at each end neck down to about 3. 5 inches internal, so the removal of the lips is for naught. I think the adding of a 3. 5 to 3. 625 ID tube within the air tube assembly is probably even better to reduce the air tumbling inside the 5-inch air tube.



Tim

The lips induce turbulence. You can take it or leave it. I happened to have a Zip Router handy which made it easy.



I may reinstall the silencer ring for a comparison. I have the feeling I lost some mpg since removing it.



Gutting the intake tube is simply a free Moores Powder Coating eliminator pipe. That pipe is not stainless.



I've got 8000 miles and my air filter barely hints of dirt. I think it's the conditions you drive in.



I did punch a large hole in the bottom of my airbox also. I have a good bit of turbo whistle. Sounds like a big rig when i lay on the throttle on the highway.

 

[Guest]

You cant feel any difference w/ it in or out!!!! Sounds good though.

 

[hasselbach]

According to Gale Banks (talked to him this last weekend at the TDR-Foothill Dodge show), the ring actually makes the turbo more efficient at all ranges and he recommends you leave it in. He felt you would lose some power and response by taking it out. Since you are hearing more noise without it, it is directly due to the air turbulence created past the squared off edge explaining why it sounds louder.



Also, I have a friend who owns a head porting shop. I took my factory air tube over on Sunday to run some tests on it. When you remove the guts from the inner portion like hoot shows, you gain nothing (proved on the flow bench) mainly because of the airflow going from 4 inch, to 5 inch, then sharply back to 4 inch (lower elbow). You create so much turbulence removing the inner unit that any gain due to increase in area is offset by the vortexing inside. The air literally rolls over when it tries to go back to 4-inches so it’s no better than before.



I simply inserted a 4-inch piece of piping (which required minor grinding of the area that hoot and others have hogged out with the router) and cut this piping at 8. 25 inches. (It is supported at each end with the modified lips opened up to approximately 4. 15 inches). Airflow went up dramatically at the same pressure drop as before (+150 CFM at same pressure drop).



Now the airflow is completely smooth though the unit. For those of you who want to pick up a few hundred CFM free for about 5 bucks, send me a message and I'll show you the parts and pictures.



Tim