You are right, they are high dollar pieces. Check on two Borlas for each one (one really really quiet and then one really really loud) and then it makes sense.

They really do have lot of parts cost in them and with most being either custom made and all st. st., it adds up very quickly. The actuator alone costs more than most Chinese (or other low cost) mufflers do.

Tom Hand

I'm interested in a quiet muffler too. My situation is a little different since the turbos will help reduce the noise too.
I have no need or desire for a switch pitch muffler.

I want quiet with as little back pressure as possible.

The driver controlled muffler design
calls out for a 'convoy' style MPG test at 70 mph,
either unloaded
or towing.

Has anyone measured the back-pressure difference between the two settings at part-throttle highway cruise?

Feets, I'd use the largest straight-through muffler you can fit. The 5" by 11" by 22" Magnaflow or Goerlich Xlerator X141 I think both would be terrific for letting the turbocharged exhaust fly through and getting rid of the noise.

360view: Regarding the back pressure measurements: they will vary greatly depending upon load and gear and engine and car but I can tell you the difference in air flow through the mufflers closed and open is very similar to stock mufflers when closed (around 35% of an open pipe) and around 55 to 60% when open (around that what typical Flowmaster flows when configured with offset offset inlets and outlets). However, please recall that under highway speeds when the throttle is not too far open, the back pressure may not and likely will not be very high no matter what mode the muffler is in. Of course, if the throttle is wide open, the back pressure will be measurably different. If I have my Barracuda out soon, I can measure it one of these days for you.

Tom Hand

has anyone tried the dynomax VT mufflers? quite till you hit it.

Yes, have had three sets and they work very well on all but the really high HP, high compresion,large cubic inch engines. Dynomax is working on the new versions for these more powerful set-ups.

We have a set on a low 12 second 360 powered 1968 Barracuda. They are very, very quiet at idle and cruise conditions, even with a 3.91. Once you put the coals to them, they open up and sound like the Welded UltraFlo.

We also have a set on Dad's low 11 second Pontiac wagon. They tend to be louder as they are not the new versions intended for big engines BUT they are still surprisingly tame for such short mufflers with such short silencing zones internally.

In both cases, there is NO DRONE. The Cuda runs tailpipes. The wagon has them at the rear with a shorter straight section of pipe following them.

Please also visit this string and read the data presented.
http://forums.performanceyears.com/forums/showthread.php?t=639125

Hope this provides enough data to help answer your question. If you are close to KC, I can help you install a set to listen to.

Tom