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Re: Sports Mufflers

Posted: Sun Sep 18, 2011 5:20 pm
by boxertwinjeff
Would the Dunstall Megaphones have a definately distinct Sound, that sets them apart, and noticably
different to say the Norton Megaphones made by Emgo? , or any other Megaphones for that matter?
or are Megaphones all fairly similar sounding? :?

Re: Sports Mufflers

Posted: Sun Sep 18, 2011 10:14 pm
by vanzen
Ken in Oklahoma wrote:...Too bad there aren't new replicas of Luftmeister mufflers.
Luftmeister NEVER made a muffler –
Either RB Racing designed and built the product,
or Luftmeister copped RB's design and had it "knocked-off".

Re: Wondering about glass packing

Posted: Sun Sep 18, 2011 10:25 pm
by richard t
[quote="Ken in Oklahoma"]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.

Ken you are corret, Over the years the bike got louder and LaDonna got older and the sound was less apealing to her, as the local cops would turn and stare at her.
Don Roberts has a set of Bubbs, on his /6 that have a throaty sound to them

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 12:46 pm
by twist
this is really sort of new to me, the science of exhaust tuning. If I understand what I've read so far, the longer pipes are actually better for performance. Why is that?It would seem that getting the exhaust out as fast as possible would allow the intake to flow better, too. My mechanical logic isn't really logic, I know but I want to learn. This is fascinating stuff to me. Sort of on the same subject: what good does wrapping the headers do, (other than protect the rider from burns)? The heat has to go somewhere and I don't think keeping it in the heads is desirable, is it? When it comes to the finned exhaust nuts, how much cooling do those finned nuts actually provide? Would using a header nut without fins really make that much difference?

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 12:49 pm
by dougie
twist wrote:this is really sort of new to me, the science of exhaust tuning.
You're lucky we aren't talking about 2-stroke bikes.

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 1:38 pm
by vanzen
twist wrote:this is really sort of new to me, the science of exhaust tuning. If I understand what I've read so far, the longer pipes are actually better for performance. Why is that?
Generally speaking, header diameter, primary length, and collector length
will affect torque delivery, torque peak, and peak HP.
It's always a balancing act.
Torque that comes on quickly and reaches peak output at usable road RPMs
are certainly desirable traits for a general purpose street bike.
Smaller diameters and longer lengths will do that.
Sport-bike tuning will often sacrifice that tractor-like torque delivery
for a bit more HP at the top and greater top end speed.
Exhaust system design may need to be different to attain those characteristics.

Performance is not an objective entity –
The term MUST be defined before qualitative terms like "better" can be applied !
The bottom line ?
The "best" exhaust system design will provide the most useful power curve
this will be different for every application
and must be defined by (the specific needs of) the individual.
twist wrote:It would seem that getting the exhaust out as fast as possible would allow the intake to flow better, too.

Exhaust theory is quite complex and not nearly as simple as all that.
A good intro article from Burns Stainless
twist wrote:...what good does wrapping the headers do ...
Wrapping causes steel headers to rust in short order.
The theory will be that wrapping retains heat within the header
and therefor increases velocity through the system.
Originally wrapping was used in racing autos to keep header heat
from affecting other components under the hood.
twist wrote:... how much cooling do those finned nuts actually provide? Would using a header nut without fins really make that much difference?
Apparently enough to justify the extra expense of a complex machined casting !
But then, the style was just so very fashionable back in the day ...
i.e.finned exhaust nuts are no longer used, even by BMW.

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 1:51 pm
by boxertwinjeff
So should I feel any difference in Performance with these hoskes I've bought
compared to the existing Staintunes?, except for sound ofcourse

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 2:03 pm
by vanzen
boxertwinjeff wrote:So should I feel any difference in Performance with these hoskes I've bought
compared to the existing Staintunes?, except for sound ofcourse
Only you are be able to share your feelings.

Staintunes, if properly tuned to the MC, are excellent mufflers.

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 2:03 pm
by chasbmw
I somehow doubt it, I find that Butt Dynos tend to be very subjective.......a proper dyno run is the only way to tell. If the hoske's are generally for sale in Germany and have a TUV certificate, then they will likely be as restrictive as stock.

IMHO. Charles

Re: Sports Mufflers

Posted: Mon Sep 19, 2011 2:03 pm
by boxertwinjeff
I know I can use Staintunes email contact form, though I need to email photos to them,
Has anyone Staintune's email address?