Variable Exhaust Note

[hipobuzz]

I don't think I have seen this discussed before.
I read a while ago on the net about a muffler that had a bypass valve inside (electrical switch) that went from muffled to straight through. Anybody ever had one or knows anything? I want a "Bullitt" sound for fun but a quiet note around my neighborhood. My next-door neighbor is a cop (but nice).
Also, does anyone know of an external (electric) bypass valve that would allow a dual system for the same effect?
Thanks

 

[woodsnake]

There are cut out valves for racing available. You put them after the headers, so that when you open the valve, the exhaust dumps straight out.

I don't know anybody that has used them on a street car. I'd just get some nice magnaflows, and run a 2 1/2 inch pipe and be done with it.

 

[2+2GT]

I know what you want:

 

[golf4283]

check these out too.

3" QTP CUTOUTS OPEN EXHUAST LIKE NEW - StangNet Mustang Classifieds

 

[Gearbanger 101]

The words "waste of time and money" comes to mind.

 

[golf4283]

He wasn't asking for our opinions. Just what options he has.

 

[Gearbanger 101]

He wasn't asking for our opinions. Just what options he has.

Actually...if you'll reread his post, opinions are exactly what he was asking for. Just because mine wasn't a positive one on the subject, doesn't make it any less valid. You need to be moving some serious exhaust flow to justify cut outs....otherwise the most they end up doing is eating up useable torque and quite frankly sounding awful.

 

[mrmustangman357]

i have cutouts on my car and makes it sound MEAN - perfect for upsetting drivers next to you on their cell phones

 

[htwheelz67]

ford racing makes dual mode mufflers with a spring loaded valve in them, at idle and normal driving it goes thru the muff when you punch it the trap door opens and its a straight thru muffler. I havent put mine on yet.

 

[70vert]

Spring loaded Ford Racing unit - how does it account for different engines?

htwheelz, I would think that Ford Racing unit would operate differently on different engines . . . I have a tired old 302 with the OE 2 barrel carburetor, for example. What if, say, I put in a 460 stroker with 2x4bbl carbs? Would it blow through the spring at all times?

I wonder what engines that spring-loaded unit is dialed in for, assuming the spring is acted on by the exhaust gases and not a loud pedal cable operation. An electrical opener would be fun, but I can imagine lots of satisfaction when your loud pedal turned into a REALLY loud pedal when you punch it.

 

[2+2GT]

Actually...if you'll reread his post, opinions are exactly what he was asking for. Just because mine wasn't a positive one on the subject, doesn't make it any less valid. You need to be moving some serious exhaust flow to justify cut outs....otherwise the most they end up doing is eating up useable torque and quite frankly sounding awful.

Actually, his question said NOTHING about cutouts, at all. He was asking about variable mufflers, which, by the way, all Corvettes have had for years.

I read a while ago on the net about a muffler that had a bypass valve inside

 

[coolblue65]

Actually, his question said NOTHING about cutouts, at all. He was asking about variable mufflers, which, by the way, all Corvettes have had for years.

uh no thats not correct, there was nothing like that on any C4 or C5 corvette, and the C6's ('05 and up) have an option for a dual mode muffler.

 

[Gearbanger 101]

Actually, his question said NOTHING about cutouts, at all. He was asking about variable mufflers, which, by the way, all Corvettes have had for years.

Convenient how you left out this part of his statement out!

I read a while ago on the net about a muffler that had a bypass valve inside (electrical switch) that went from muffled to straight through.

Just because it doesn't open strait out in front of the muffler, directly into the atmosphere, doesn't make it any less a "cut out" design. In one instance it utilizes the exhaust packing, baffles, material, etc and in the next with the flick of a switch an adjustment of a valve(s) (be it internal or external) it bypasses the sound control altogether and runs strait through.

So if this isn’t a cut out design, how exactly would you define it then?

 

[2+2GT]

Just because it doesn't open strait out in front of the muffler, directly into the atmosphere, doesn't make it any less a "cut out" design. In one instance it utilizes the exhaust packing, baffles, material, etc and in the next with the flick of a switch an adjustment of a valve(s) (be it internal or external) it bypasses the sound control altogether and runs strait through.

So if this isn’t a cut out design, how exactly would you define it then?

What part of "out" don't you understand? Internal is INside the muffler, cutoutss are OUTside the muffler. By your definition, any straight-thorough is a cutout.

 

[Gearbanger 101]

What part of "out" don't you understand? Internal is INside the muffler, cutoutss are OUTside the muffler. By your definition, any straight-thorough is a cutout.

Um....no, the word "out" when referring to exhaust cutout implies an alternate route used to remotely bypass the primary exhaust system.....a secondary means of cutting out the middle man (sound deadening material(s), resonator(s), converter(s), etc) from the equation, so to speak.

The definition is not dependant on the placement of said junction within the exhaust system. Whether the placement occurs right off the collector, before the converter(s), before the muffler(s), or occurs within the body of the mufflers itself has nothing to do with the interpretation of its definition. Its definition is however soley dependant on whether or not a secondary routing exists.

A strait through exhaust is just that...a strait through exhaust. There is no secondary system or bypassing involved since a strait through exhaust is a singular exhaust routing, with no secondary involvements.

Get it now, or do I need to draw you a picture?

 

[2+2GT]

The definition is not dependant on the placement of said junction within the exhaust system. Whether the placement occurs right off the collector, before the converter(s), before the muffler(s), or occurs within the body of the mufflers itself has nothing to do with the interpretation of its definition. Its definition is however soley dependant on whether or not a secondary routing exists.

Get it now, or do I need to draw you a picture?

You mean like the picture I posted above of exactly such mufflers?

 

[Gearbanger 101]

You mean like the picture I posted above of exactly such mufflers?

Sure, if you want.

They're built as a vacuum operated exhaust design...I would imagine similar to (and probably a more refined version) that of the short lived design of the early 70's Pontiac GTO. In one mode, they run full baffling and sound deadening and in the next (presumably with the flip of a switch, or pull of a cable) the system redirects the exhaust path is via the vacuum operated valve to an alternate pathway within the muffler containing either reduced baffling or sound deadening material, or depending on how you'd like it set up....none at all.

This is the exact same concept as the traditional exhaust cut out, only its done so within the confines of the muffler itself. Same ****, different pile. I really don't see what your argument is here?

 

[2+2GT]

I really don't see what your argument is here?

Semantics.

 

[bnickel]

Sure, if you want.

They're built as a vacuum operated exhaust design...I would imagine similar to (and probably a more refined version) that of the short lived design of the early 70's Pontiac GTO. In one mode, they run full baffling and sound deadening and in the next (presumably with the flip of a switch, or pull of a cable) the system redirects the exhaust path is via the vacuum operated valve to an alternate pathway within the muffler containing either reduced baffling or sound deadening material, or depending on how you'd like it set up....none at all.

This is the exact same concept as the traditional exhaust cut out, only its done so within the confines of the muffler itself. Same ****, different pile. I really don't see what your argument is here?

well since you are such an ass let's look at things this way.... he wants a MUFFLER that is internally bypassed but still runs through the full exhaust system, your suggestion of using a cutout would in most cases mean that the exhaust would exit the cutout BEFORE the rest of the exhaust system, thereby actually being louder than if it ran through the exhaust system. all the bends and curves and even the tubing itself reduces the sound level as the exhaust passes through, which is not the case when using cutouts before the mufflers unless you run a seperate exhaust system out to the back of the car which is really stupid.

BTW, there is another option for a muffler with an internal bypass to change the sound level that is a good bit cheaper than the repro GTO system from Waldrons.

VaraFlow Tunable Muffler

 

[2+2GT]

BTW, there is another option for a muffler with an internal bypass to change the sound level that is a good bit cheaper than the repro GTO system from Waldrons.

They also offer Smithy's, a type of muffler used on many early Corvettes. It's straight through, but not a glasspack, it uses baffles. Pretty tame at idle and low power, but gets loud when you stomp the gas. That's my idea of a variable exhaust, controlled by my foot.