I had another thought on my commute this morning (I know it's dangerous). I have functional perforated tube mufflers that are still functional. What if instead of using regular old tubing to go from the y-pipe portion of the muffler I use these rather 'small' mufflers instead. I see the benefit two fold:
1) I save money by not buying additional stainless steel tube
2) I get a quieter note because they have muffeling capability

Basically I'm doing what Ted suggested about ferrari and making a huge muffler :).

In addition to this though what if I combined a diffuser and a muffler together? Have a large perferated tube design feed into a rather flat but large muffler filled with stainless steel wool and outputs into two exhaust mufflers on the side in the normal location.

Thoughts? (I want to see if anyone can spot the issue with the latter idea :))

T, the RB mufflers are the best for the rotary IMO. I have been using them for years with fair success in accomplishing what you are trying to do......quiet without losing too much performance. I have had to modify a few RB pre-silencers to fit in limited areas and was able to see the internals, which is as Ted mentions...perforated and offset with a bunch of curly stainless noise suppression material.

You may want to also consider a heavier wall thickness if you purchase tubing...this takes out a good bit of the "metallic" sound in the rotary exhaust.

On a different note, I will shoot you a PM soon about seeing if you can help me with a intake plenum design for a sidedraft Weber (DCOE).

Todd B.
(formerly of No Limit Industires in Alabama)

Is this their normal/self branded mufflers or their universal mufflers they offer?
Sounds like a plan.

This is exactly what we're going to do with our 20B project...

Magnaflow center 4" in, dual 3" out
...into...
twin 3" in / 3" out offset mufflers in the back

It should to pretty good noise suppression.


-Ted

Will you have to worry about the gas tank in the stock location? AKA if you're running hot you'll heat the gas in the stock location and if there's an accident...?

Dunno, but good question...

The owner of the car is doing all the fab'ing on that exhaust.
He's the certified weldor.

The layout sorta mimics the Racing Beat / RS*R FC turbo exhaust, with the exception of the center muffler.
We're hoping that center muffler will help quiet things down.

We were running a 4" in / out center muffler, but it was still too loud.
We've gotten warnings here in Hawaii for exhaust noise - kinda rare, so it's pretty loud.


-Ted

hmmm.... Interesting thought. Let me know how it turns out. I may potentially do a similar route when I'm in a house.

Their normal mufflers/pre-silencers that are included with their systems. I have never used one of their universal mufflers.

I am trying something a little different on the current system. I will be using a Vibrant stainless pre silencer to see if it holds up like the RB units. It costs about $100 less than the RB and stated that it was for higher temps than standard mufflers. I have a feeling that within the first few thousand miles, the sound deadening material (even though it is stainless similar to the RB) will be burned out and I will have a hollow resonator.

Nice, that's my exact setup with a different sizes

I've used the vibrant tubing in my exhausts. Holds up quite well. Can't speak about their muffles though.

Just out of curiosity where is everyone finding these offset mufflers they're talking about? Everyone I've looked at doesn't seem like it would hold up. I'm half tempted to lay down some real coin and buy the RB y-pipe and mufflers.

Magnaflow
Walker Dynomax UltraFLO
Borla

That's the ones that come to mind right now.


-Ted

welp the fine state officers of VA have decided to give me a birthday present in the form of another exhaust ticket. :)

alright, so I looked a tad bit closer at the 'oem equivalent' system that racing beat provides and have noticed that what I thought were cylindrical mufflers are actually oval. With that in mind I've got a fair few selections to which I can purchase (since i'm no longer limiting myself to the round style mufflers). This is what I have thus far:
From Magna Flow:
Mufflers: 12256 $81.82
Y-pipe: 12198 $90.88

From Flowmaster:
Y-pipe chambered: 80430402 $79.95

From Borla
Mufflers: 40665 $168.95

From those choices (or any others you could recommend) which would provide me with the most performance? (If it's still too loud I'll just get the augor/butt plug and through it in the resonator)

Also, I wrapped my entire system from the turbo all the way back to the muffler with heat wrap which helped big time. Soaked up a lot of the metal sound and deepened the tone some.

Using a thicker wall tubing will also have a similar effect. Stainless is better also in noise suppression than regular mild steel. But this will add to cost... But as usual, you get what you pay for.