Boxerworks.com

I gotta say, i have the Norton Pea Shooter replicas on my /5 Cafe bike (with R100 engine in it) and they make the bike sound nice and mean. They are loud, but not Harley loud. They are 'throaty' which compliment's the bike's style. And the performance of that engine is great! VS - hearing that bike go by and sound like a sewing machine? It would be comical.

The sound of my R100s with Kiehan's on it seems appropriate. Not loud, but not too quiet.

Ever drive (or ride in) a Prius? You can't tell if the car is on when it is running on electric. My brain is conditioned that when i hear a noise, i know the vehicle is running. i swear i've almost gotten myself run over by those cars because i didn't hear them coming.

I can see wanting to break the BMW mold and put a different pipe on for aesthetic reasons. It's nice to have something unique and custom. Flatracer.com sells a bunch of short, and unique exhausts that make me ponder putting them on my next bike build...

boxertwinjeff wrote:...
But, ahhh, there's nothing like that sweet sound of a British twin!!

Especially with open megaphones!

I just attended a 50th High School reunion. Three of my old riding buddies were there and one of the things reminisced about was the sweet sound of my '57 Triumph Thunderbird with its stock 1 3/4" headers and open megaphones. The overrun was the sound that most delighted.

I still have the bike, with its megaphones. I am planning on actually restoring it within a couple years. But if and when I do I will be running it with baffled and capped megaphones.


Ken, soon to be baffled in Oklahoma

for many years LaDonna's R75 ran with Dunstalls megaphones that were about 4in shorter than stock, untill we went back to stock you could tell it was her from 3 blocks away especially after the packing went away, it had a sound all its own. JCW use to sell a knock of for about $50

This is more of an academic question, if and until I get my old Triumph T-bird going again.

Glass packed mufflers (such as cherry bombs) on cars always had an appealing sound, with a throaty subdued sound, which got louder and louder over time. It wasn't the noise we looked for as much as the sound of latent power, whether on a V8 engine or a single or twin cylinder Brit bike. But glass packed mufflers, whether "cherry bomb" type or closed megaphones seem doomed to failure; in the sense that over time the glass gets blown out the exhaust until you have little or none left. The sound is still somewhat subdued but becomes increasingly socially unacceptable.

In the case of a megaphone muffler or any straight through muffler that you can take apart you can re-wrap the core with fiberglass, but it will get blown out again. I wonder if this problem can be minimized by one or two approaches that entered my fertile mind. One would be to wrap the core with heavy glass cloth (not matt) used for fiberglass work. I'm wondering if this heavy cloth, tightly wrapped, and maybe even surrounded by aluminum window screen, would survive a lot longer.

A second approach that I'm wondering about would be to surround the core with fairly coarse stainless steel wool. I'm thinking that stainless steel wouldn't be subject to rusting out (or course) or breaking into bits (like glass presumably does).

Both the fiberglass cloth and stainless steel wool would be spendy, which presumably wouldn't be done on a commercial basis because the extra cost (never mind the benefit) would render the product uncompetitive in the market place.

What one would accomplish with this is a pleasing noise that is going to be a bit socially responsible (especially if one chooses when and where to let 'er rip) at the cost of some extra bucks.

As an aside, Randy and I both listened to that same /5 with Luftmeister mufflers and we both found the sound delightful. I've secured a set of those mufflers on ebay (thanks to Randy letting me know about them), but I've been reluctant to put them on a bike because of uncertainty about my ability to tune the carbs effectively and not actually give up performance. But now that I'm spending more time in Boise, ID, there is a dyno facility I could go to, with exhaust analysis capabilities (I think). I'm inclined to put them on one of my airheads and give it a shot. Looking at the Luftmeisters I believe the end caps can be made to come off and be replaced without screwing things up.


Ken

Major Softie wrote: Running "shorty" exhausts is a purely aesthetic choice that cannot be defended from a performance standpoint.

Even as I might agree with it's essence as it applies to streetable MCs.
I will find the above statement objectionable –
Both qualifying terms ( "shorty" and "performance" ) are used without definition, restriction, or quantification.
In fact, each or both of these terms might be described in such a way as to make the Major's statement false.

"Shorty" exhausts designed from a (well defined and well executed) performance standpoint:




My thoughts -

Exhaust systems that vary (esp. significantly) from stock diameter,length, and volume
potentially disrupt the essential engineered design balance of intake-head-exhaust.
Changes to the exhaust must be accompanied by appropriate changes to the rest of the system
if a restructuring of performance characteristics will truly be "the" goal.

Increased noise does not infer increased HP or peak torque.

Expected "Performance" must first be defined in order to evaluate the function of any given exhaust system.
Obviously, the system requirements of a street bike
will be quite different than those required of a road-race bike or a drag bike.
Just as the exhaust system of a "chopper" or a "custom"
might typically be an exercise that begins and ends with the visual consideration.

vanzen@rockerboxer.com wrote:

Major Softie wrote: Running "shorty" exhausts is a purely aesthetic choice that cannot be defended from a performance standpoint.

Even as I might agree with it's essence as it applies to streetable MCs.
I will find the above statement objectionable –
Both qualifying terms ( "shorty" and "performance" ) are used without definition, restriction, or quantification.
In fact, each or both of these terms might be described in such a way as to make the Major's statement false.

"Shorty" exhausts designed from a (well defined and well executed) performance standpoint:



# Like Vanzen points out, I found if the Airhead headers were more or less stock you could install about any muffler with little or no rejetting

Some Muffler systems gave a diffence that you can feel when you go from a stock muffler to a more open one, getting out the exhaust is a Key element

My thoughts -
Exhaust systems that vary (esp. significantly) from stock diameter,length, and volume
potentially disrupt the essential engineered design balance of intake-head-exhaust.
Changes to the exhaust must be accompanied by appropriate changes to the rest of the system
if a restructuring of performance characteristics will truly be "the" goal.

Increased noise does not infer increased HP or peak torque.

Expected "Performance" must first be defined in order to evaluate the function of any given exhaust system.
Obviously, the system requirements of a street bike
will be quite different than those required of a road-race bike or a drag bike.
Just as the exhaust system of a "chopper" or a "custom"
might typically be an exercise that begins and ends with the visual consideration.

the main thing to avoid is any cold air back track and sonic feed back

Hey Ken from Okkie, What's that Ebay seller who sells the Luftmeister replicas call himself as in his User name?

boxertwinjeff wrote:Hey Ken from Okkie, What's that Ebay seller who sells the Luftmeister replicas call himself as in his User name?

Actually, it wasn't a Luftmeister replica. It was the real thing. He was a doctor in some place like St. Louis and he only had that one set.

Too bad there aren't new replicas of Luftmeister mufflers. That would, presumably, really upset Matt Capri. (Which would be a delightful bit of irony since Matt Capri has been accused of knocking off a lot of people's intellectual property and just generally trying to screw customers and dealers alike.)


Ken