Muffler Testing, etc.

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VOETOM

VOETOM

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Greetings, we have been doing a lot of muffler testing since about 1988 on big Pontiacs and our 340-360 cars. Also, I have been playing with vacuum operated mufflers which are not meant to be race pieces but are great for those wanting a dead stock sound on the way to a show but want to be able to make Flowmaster noise levels once you get there.

If anyone is interested in seeing some data or learning about the mufflers, be glad to post some. Otherwise, thanks for the site and for the opportunity to be able to read about others' work and experiences.
Tom
 
Tom, would this also included Db readings in and out of the car?
Great idea!
Great post!
 
Would love to see some test results. That Pontiac wagon is killer !
 
We have the sound levels outside but did not attempt inside due to the engine being on the stand. I have found that the results translate very well between engines, in other words even though it is only a 5500 rpm Pontiac, we used to record sounds for the CD we made, the fact that it was 462 cu. in. and around 9.5:1 compression gives pretty col sound quality and type comparisons.

Yep, the wagon runs hard enough that we can tell which mufflers really work and which ones work "okay".

I have learned that sound quality is a personal preference and many like the sound from mufflers or systems that may not run as well as others. Others do not like the dead silence we strive for.

The shots show my 2.5" VOE mufflers under my car and another set on a 70-71 GTO.

It is all fun,I love mufflers and muffler experiments no matter what type they may be!
Tom

VOECUDAUNDER.JPG


VOECUDAUNDERREAR.JPG


DCE muffler installation3.jpg
 
My mufflers have readings very similar to this; all from 10 feet from the tailpipe's tips.
Quiet Loud
Idle 68 dBA 78 dBA
2200 81.5 dBA 92.5 dBA
3500 88 dBA 99 dBA.

Air flow is right around stock when quiet at ~ 40% of a straight pipe and in the same level as typical two chamber, 2.5", offset-offset, chambered mufflers at 55% of an open straight pipe when in the open mode. For comparison, "good" mufflers will flow 75 to 105% of a typical muffler-length straight pipe. These VOE's are not performance mufflers as such as just way cool to drive around with.
Tom
 
Vacuum operated mufflers. I had an idea once, not like this, similar in idea in away though.
 
http://www.waldronexhaust.com/drivercontrolledexhaust.htm


For a brief period in 1969 & 1970, GTO buyers were able to purchase an option known as “Vacuum Operated Exhaust”. It was one of the industry’s most unusual options; dual-mode mufflers - controlled by the driver - that could be operated in “Quiet” or “Tiger” (Open) modes.



VOE-2™ Model
(For 70-72 GTO/LeMans/Tempest)



The VOE-2™ model is a close reproduction of the original GTO VOE muffler. It is also a “direct fit” for any 1970-72 Pontiac Tempest/LeMans/GTO with dual exhaust. If you are lucky enough to have a GTO that was originally equipped with the VOE option, with or without Ram Air, you can restore the VOE function by purchasing the mufflers only, without the control kit.


DCE™ Universal Model
(For almost everyone else!)



Waldron’s has a patent pending design that provides the look and sound of the original VOE Muffler for other vehicles. The universal DCE™ Mufflers are available in 14”, 18”, 19” and 21” case lengths, with offset inlets and offset OR center outlets. Available inlet and outlet diameters include 2”, 2 ¼” and 2 ½”. They will fit a wide variety of AMC, Ford, Dodge, Plymouth, Mercury, GMC, Chevrolet, Buick, Oldsmobile and Chrysler cars and trucks.



And of course, they can be utilized in most street rod or hot rod applications!



Universal DCE™ mufflers are slightly louder than the VOE-2™ model in the Quiet mode. In the Open mode, they sound and flow the same as the VOE-2™ model.



Disclaimer: Waldron’s recommends that you verify your local sound ordinances before driving in OPEN mode to avoid tickets.



Some of the applications for the universal DCE™ model:
68-98 Mustang (exc. 74-83)
70-73 Corvette
64-84 Most GM full size including Buick, Chevrolet, Pontiac & Oldsmobile.
68-85 Chevrolet & GMC Trucks
60-80 Most Chrysler, Dodge & Plymouth
68-76 Thunderbird
66-71 Ford Fairlane & Torino
67-71 Mercury Comet & Montego
79-85 Dodge Trucks
66-71 AMC
And many many more—Check the muffler check the DCE Application Chart for direct fit applications.



DCE Application Chart (Printable PDF, Requires Adobe Reader )



DCE Customer Brochure (Printable PDF, Requires Adobe Reader )


http://www.youtube.com/watch?v=oX5i4_CQqb8
 
Cool, I like that idea. I have 4 mufflers on my car now since I`m not a noisy muffler guy. These make noise only when they need to.
 
Very cool, I too am one fascinated by the different set ups and configurations for exhaust systems....

Tell us more about the internal workings of the mufflers :read2:
 
Caveman, yessir, that is my 340 with one of the GTO sets on it for sound testing. The real ones are even better but I could not get the microphones in the right spot when I made that video.

I worked very closely with Joe at Waldron on this project. The cool thing is the ones he can make for A-bodies can be right at the 18" and 4.25" by 10.25" shell. He can go 2.25" or 2.5" like I did my prototype set.

TS, they use a large plate/valve that covers a bypass internally and when closed by spring pressure, they are like the stock 340 three pass muffler but when open using the vacuum actuator, the exhaust bypasses two of the tubes and exits through openings in the outlet bushing.

The vacuum signal is acquired from the back of the intake and then feeds a canister hidden under the driver's side front fender. The cannister connects to the switch which I have in my ashtray replacing the nitrous switch (from 1979) and then it connects to a nylon tube going back to the mufflers. Any vacuum signal from around nine inches of mercury and higher will actuate these.

We are both seeing about 7 to 10 dBA difference across the board (between open and closed) pretty much independently of the engine size except for the lower compression or smaller HP engines.

VOECUDAENG.jpg
 
Three inchers do not have much space to play with internally but I think Joe is messing with them now. By the way, I have no connection to Waldron's; I just turned the project over to them as they are a well respected company and I was just a person doing it for fun. I make no money off sales or anything.
Email Joe and he can let you know about sizing.

It is a pretty cool idea and they are fun to mess with. Tom
 
The new Corvette has a similar switch in the passenger compartment for the exhaust system. Select quiet or performance.
I like your idea, and I think it's the coolest thing I've seen in a long time.

George
 
George,

I thought so too, that is why I spent several years building and playing with these. It was a neat idea when it was created in 1962 by a gentleman that is still working hard today; between his brain power and my exhaust connections, we were able to bring them back to life 35 years after the last car was built with them.

Later, I'll get some numbers put up about other mufflers we were fortunate to have been able to test.
Tom
 
I have a QuickTime electric cutout on my Dodge Ram. It uses a electric motor to open and close the cutout. Looks like a choke plate on a carb. I like those mufflers your have because they sound like they seal better. The cutout used to seal really well when new but I got a very little "hiss" that I can hear now when closed. Most say it needs cleaning but I haven't looked at it.
 
Tom-
You mentioned that you have exhaust connections.
Would you be able to help me acquire a set of front pipes for my 69 Dart with dual exhaust? I have the down pipes, and the over axle pipes as well as the mufflers and tips, but I cannot find the front pipes available seperately. The entire exhaust system can be purchased as a kit from various places, but the price is out of reach for me as it approached $500 without mufflers for a quality kit.
I am in Connecticut if that will help.

Thanks,
George
 
George,

Along with Accurate, might also talk to Joe at Waldron. He can and will bend anything he has jigs for. He made me the tailpipes for my 69 Cuda and I am sure he can create the front pipes for you. Unlike the universal ones that tend to make the mufflers hang too low, he can get the kickup bends put in right where the mufflers attach. They are not mandrel bent pipes but for stockers not being raced, that is A-OK.
www.waldronexhuast.com and http://accurateltd.com/frontpage.htm

Tom
 
Cool to see the technology resurface...This would have been pretty trick back in the day...

With blatantly obvious knock-offs (header caps) this would have been a discrete way to have a little fun 8)

Well I guess cast iron cutouts might have been around, but they just seem lame, haha...
 
74Burntorange said:
i may have missed it, but what is the purpose of these?
Click to expand...

It`s like having two mufflers in one, a quiet cruising muffler with 3 chambers and/or a performance muffler that`s essentially straight through. When you crack the throttle wide open (dump the vacuum) the servos close two of the chambers and create an unobstructed path for the exhaust to exit. It`s a performance muffler when you need it and quiet when you don`t.
 
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