guys,
always lots of questions about which brand of mufflers and so on. i've got a slightly different one

lets assume 2x 2.5 exhaust, "sports" mufflers. you def know its a bent 8 when the guy stands on it.

How come some systems go quiet when you take your foot off and others sound just as good when you get off as when you get on the go pedal???

 

The internal construction of the muffler is critical. The best system I have seen was designed for the 65 289HP, called the Arvinode. It used tuned waveform tubes under the car, and had no mufflers at all. Really.

http://www.youtube.com/watch?v=CnFXyLgcvLg

 

The term "muffler" can be used loosely in some cases. According to the State of California, tuned waveform tubes ARE classified under state law as a muffler, since there are no requirements for external dimensions or internal construction for a muffler, only that it be a device that is part of the exhaust system designed to suppress or control sound emissions. As long as it keeps the sound under the 95dB limit for a modified exhaust, contains a device that does it, and is in a good state of repair, California says it's a street legal muffler.

But to answer your question, yes, the design of the muffler plays a huge role. The pipe size and shape, the use of an x or h, and the tune will also effect sound under engine decel. Even things like the cam, since a larger overlap will allow more charge to spill out into the exhaust, can make a difference. More fuel in the exhaust that burns in the pipes will make more noise...and even some newer EFI cars actually shut fuel off during engine decel to increase economy, so you get no sound under decel since combustion stops.

 

sounds great...but how loud is it?

the mufflers i have now are straight thru but, despite being outrageously loud as you increase revs, they hardly contribute when you get off the gas.

i'm looking for something that is loud without being a complete cop magnet. Some quality over quantity. but because i like spirited driving between corners i want something that sounds good on decel too.

is it possible?

 

i'm 2x 2.25 with an H. 347 mild build around 400hp. Currently bordering on race car loud. Certainly above 95 dB which i reckon is about our limit here too.

I'm not necessarily looking for a brand because not many American mufflers are available here at an economical price. More a style of construction - what do i ask the shop man for to achieve the effect I'm after?

Thanks for your help!

 

OK, how about a muffler that can be quiet or loud with the touch of a button on the dash?



http://waldronexhaust.com/drivercontrolledexhaust.htm

 

i've never seen that before! kind of like in built cut-outs. Would have been very cool in the day.

volume control isnt really the thing i'm after. Ive heard loud exhausts and relatively quiet exhausts that sound good on both acceleration and deceleration.

what is it about a muffler or exhaust system that gives it a good sound on the way down as well?

 

Wow, that is probobly the coolest exhaust I have ever seen. It was neat to read about that as an option for the GTO's back in the day. I wonder how many ordered them with that option.

 

I know what your getting at. I'm kinda curious to to the answer to this question as well.