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Stock, quiet, multi - chambered Motorbike Mufflers - Results are in

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sander288 "Bolt-on Master"

1,404 posts · joined Aug 2008 ·

#760781
If a UFO came down from space and zapped you with a red laser and then a green one which one would hurt more...

its more than the muffler.... and one should surfice
BMW R65 LS
1967 1300 Deluxe
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barls Administrator Causer of Chaos and Mayhem

9,476 posts · joined Jun 2004 ·

#760784
its the system as a whole mainly its from the heads back.
“We all pay for life with death, so everything in between should be free.” Bill Hicks
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Phil74Camper Head in the Clouds

2,703 posts · joined Aug 2002 ·

#760877
You don't normally see VW exhaust systems with more than one muffler. There are 4-into-1 systems that then branch off to a muffler at each side, but they have no advantage over 1 muffler. 2 mufflers only work when they are in series, not in parallel.

A motorbike muffler ought to be more efficient and quieter than, say a fibreglass 'hot dog' style single muffler, and is around the same size.

The RPM range of VW engines is a lot less than motorbike engines. Bike mufflers are designed to quieten the 10,000+ rpm screams that VW engines will never produce. How quiet are bike mufflers up to, say, 5000 rpm, which is what the VW engine will do?

What sort of VW engine are you planning to put a bike muffler on? Stocker, hot street, race??

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#760884
If I recall correctly, Jeff Unwin used a bike muffler on the 2213cc(?)
hellbug back in the early 90's(?) when he ren a Raleigh Raceway near Nambucca Heads.

Car was still fast, even with a loose intake manifold, and sounded awesome.
westi wrote:That's mad Alan.

Sides Veteran Volks Folk

2,220 posts · joined May 2007 ·

#760887
I know of a couple of hot beetles that are getting around with bike muffler's on 'em... Gracey (on here) being one of em... and they're all getting good results.

The local muffler dude who's also into racing (BMW's rather than VW's unfortunately) was telling me that a single, superbike style disassembleable (is that even a word?) muffler would work brilliantly on a VW...
VWDCQ vice pres & web dude - vwdcqinc.org.au
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squizy Thinking about another dub...maybe

4,082 posts · joined Dec 2002 ·

#760892
Pete Muhm used to run a bike muffler on his Cabrio in the 80's. Knowing Pete, it did f all.

71-BEETLE-SEDAN AKA Josh

1,058 posts · joined Mar 2009 ·

#760930
I was gunna do it but i went the cannon way, i think joel used to run one like a motor bike one on his black bug.

greedy53 Bishop of Volkswagenism

3,062 posts · joined Mar 2006 ·

#760933
What happened to the space ship
👍👍😂🙅🥷😬🤓

mnsKmobi Wolfsburg Wizard

589 posts · joined Aug 2002 ·

#761043
bus914 wrote:If a bike makes 135HP at 10000 rpm with two mufflers, but a modified VW with double the bike's displacement makes 60HP at 4000 rpm, would it need one bike muffler or two?
Why do you want to do it? I remember someone using Harley mufflers b/c he could get them v. cheap. (I think he had two) Other than that I can't see any advantage.

DubCty Slammed & Awesome Dubber

95 posts · joined Jun 2009 ·

#761106
sander288 wrote:If a UFO came down from space and zapped you with a red laser and then a green one which one would hurt more...

its more than the muffler.... and one should surfice
Red hands down - Green on Sundays!
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bus914 Custom Title Time!

1,230 posts · joined Aug 2002 ·

#761108
mnsKmobi wrote:Why do you want to do it? .. someone ...could get them v. cheap.

High quality units can be had for a song. It seems a motorcyclist wouldn't be caught dead with a stock pipe, so they rather give them away.
Phil74Camper wrote:....Bike mufflers are designed to quieten the 10,000+ rpm screams ....
The ones I've got came of a 4 stroke 2cyl bike, with one muffler per cylinder. This means that each muffler gets only 5000 pulses at 10000rpm. This will be the sweet spot, tuned to match the engines horsepower peak.

As the bike has roughly half the displacement, each of the bike's pistons displaces a very similar volume to each of the car's.

A 4 stroke 4cyl VW will fire two pistons on every revolution. So at 5000rpm a single muffler in a 4 into 1 setup will get 10000 pulses ...too much.

5000 pulses will occur at just 2500rpm. ....maybe good for a Kombi.

So you do need two mufflers, in a 2 into 1 config. That will give 5000 pulses at 5000rpm. Perfect...just as the engineer intended.

The usual setup for a VW with this combo is called cannons.

.....but, because the firing order is 1,4,3,2 the pulses are not evenly spaced with typical cannons, ie. cyl 1 exhaust will not make it out of the pipe before cyl 4 exhaust enters the muffler, and then its a long wait while 3 and 2 fire before 1 fires again.

Conclusion, these mufflers won't work, unless a 2 into 1 setup is fabricated that links the even cylinders together and the odd ones together.

Or so I think anyway 😵‍💫
[img]https://i4.ytimg.com/vi/KOKlJpsfCyk/default.jpg[/img] Click the thumbnail for video👍

BiX Veteran Volks Folk

2,499 posts · joined Sep 2002 ·

#761230
If you go the after market route, most motorbike mufflers come with a baffle that is easily removable. Though most after market ones cost between 500 and 1200 new....

If anybody in brisbane wants, I have a std muffler from a SV650 they can have to play with. Its got some gravel rash, but hidden under a car it would be fine. It comes from a 650 V twin, that spins to 12000 rpm (for your calcs above). it does have the standard baffle inside, so makes thisng pretty quiet and I think would restrict flow.

Cheers

Drew
I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!

bus914 Custom Title Time!

1,230 posts · joined Aug 2002 ·

#764212
My post above may have read like a convincing argument.😂

....but... I now think that one muffler will work a treat.👍

The reason being, that the bike has peak a torque figure that I think is very near what I get from the car. This means that the bike has near 100% better volumetric efficiency. So each pulse from the VW engine will have half the volume.

I'll post the results when available if anyone is interested.

The donor bike looks like this by the way:

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[img]https://i4.ytimg.com/vi/KOKlJpsfCyk/default.jpg[/img] Click the thumbnail for video👍

Sides Veteran Volks Folk

2,220 posts · joined May 2007 ·

#816010
Sounds all right... good that you gave it a try !!!

👍

Don't suppose you've gotten a noise reading off of it ??? (free revving at a stable 5000rpm measured at 5m is a common one to come across at circuits)

Also keen to hear the details, specs, costs etc. if you don't mind sharing...
VWDCQ vice pres & web dude - vwdcqinc.org.au
Join a car club - get car peeps

My toys
'70 Hillclimb Bug 'Jezebel' w/- Haltech EFI - http://bit.ly/VwTNtQ
'60 KG Coupe - resto kinda started
01 New Beetle - gf's car, but I turn the spanners

HappyDaze Superannuated

2,887 posts · joined Jun 2009 ·

#816016
Anyhow Shaun, what WOULD hurt the most - a red laser, or a green one❓

I suppose getting run over by a Ford Laser would be even worse, red or green.😂
I'd rather wear a Beetle out by racing it than by polishing it!

SuperOwen Fahrvergnugen

868 posts · joined Jan 2009 ·

#817345
A bit hard to tell from the video but it sounds quite nice to me. Better clearance than fatboy setups etc as well. Something else to play with is the length of the entire system, I found that made a big difference to the note on my old 1835.