riding without mufflers

7000 · Jun 21, 2015

So I have my mufflers off to do some cleaning, and I decided to go around the block to see what it sounds like. Very loud, very nice rumble as I back off the gas...something the neighbors would tire of quickly. What I'd like to know is, what kind of damage would I be doing to the engine. I guess at least it would be hard on the exhaust nuts, as those are all that are holding pipes on.

ashman · Jun 21, 2015

You would lose a bit of back pressure, mid range power and over time would proberly burn out a exhaust valve and how many tickets you would get, is it worth it, but all good to give it a try, when I first built my Featherbed 850 in the 80s I had a exhaust shop make and bend my pipes to the axle, got them chromed and rode it with no mufflers for a week before cutting them down for the mufflers, I am still running them header pipes after 35 years but have gone throught a few mufflers.

Ashley

Hobot · Jun 21, 2015

i had two 750s with open pipes that ran better than scalded cats. Your nuts are relieved as not being tugged and bounced by muffler mass and rubber hangers to headers and head threads will thankyou. If it takes throttle well from off idle and can semi lug going slow then likely rich enough tune to just Blap & Blast around till someone shoots and you or the police get ya, if they can catch ya of course as should notice nicer power especially nearing red line. Might lift the carb needles to see if happier yet. Peashooter are about 6 lb and the hangers another lb or so, so over a dozen lb off to notice too.

o0norton0o · Jun 21, 2015

I have dustall decibels on my bike. they make a nice sound. They are loud, which is a good thing in modern traffic where people are texting while they drive so there's a chance they may not see you. With a pair of dunstall's they will definately know you're there from the sound...

Danno · Jun 21, 2015

I think the seat-of-the-pants sensation of speed with open pipes is what Harley riders rely on to get their kicks without having to go very fast.

7000 · Jun 21, 2015

That sounds about right Danno, plus I felt a bit conspicuous. But it was exilarating, and I might do it one more time before it's all back together.

worntorn · Jun 21, 2015

I saw a dyno test of the giant Harley factory open pipes vs.standard exhaust with mufflers The standard pipes are already quite free flowing and somewhat tuned to the engine whereas the large diameter open pipes must be a bit too free flowing, ie not much scavenging happening.
The open pipe bike made six horsepower LESS than the muffled system. And a/whole lot more noise!

Glen

Anonymous · Jun 21, 2015

Hi 7000.
Good luck with open headers! Maybe add Fishtails for the 'look'.
I recently modified the muffler guts I built in the '80s: removed an internal baffle cap then added a 90° exit elbowed down to save my ears.
The discrete header length remains unchanged so only back pressure may be altered slightly.
A sweeter sound, especially on long hauls, with better 'flow' (yet to be objectively assessed).
Ta.

Danno · Jun 22, 2015

worntorn said:
I saw a dyno test of the giant Harley factory open pipes vs.standard exhaust with mufflers The standard pipes are already quite free flowing and somewhat tuned to the engine whereas the large diameter open pipes must be a bit too free flowing, ie not much scavenging happening.
The open pipe bike made six horsepower LESS than the muffled system. And a/whole lot more noise!

Glen

Part of that has to do with the length and volume of the system. The other part is why the old saw, "Change one thing and you change everything" which is to say changing one thing does not necessarily constitute an improvement without changing other things to suit. Tuning for open pipes is different than tuning for a whole system and the desired effects are different. One setup will accomplish different goals than another. If the goal is maximum noise, open pipes certainly can't be beat.

Hobot · Jun 22, 2015

Mostly just have to richnen up some and maybe retard a tad with the better flow pass though. A gutted out hollow Dunstall longdong megaphone magnifies the headers to ear bursting up close.

Torontonian · Jun 22, 2015

If the goal is maximum noise and maximum flamage dramas , try no exhaust system whatsoever ! We tried it at night once just for fun and o.M.G. it was good. The exhaust ports are angled out enough to clear frame tubes and wires so give it a go. Loud ,dramatic stuff for brief period of time obviously. :wink:

MikeM · Jun 22, 2015

Danno said:
I think the seat-of-the-pants sensation of speed with open pipes is what Harley riders rely on to get their kicks without having to go very fast.

Not necessarily true. Some of us do ride other brands.

elefantrider · Jun 23, 2015

It's only loud when you get on it. If you short shift, the sound dissipates pretty quickly with a little distance.

mschmitz57 · Jun 23, 2015

Chicken Spears! Chicken Spears!

https://www.youtube.com/watch?v=25RDJqjauLI

Hobot · Jun 23, 2015

Naw a Commando has a refined pleasnatly loud open header sound that ya just want to merge with more rather than rotten potato banging obnoxiously - see if this is too much to bear or pleasing to hear a great SNorton sound
[video]https://www.youtube.com/watch?v=fkYpWySknw8[/video]

riding without mufflers

7000

ashman

Hobot

o0norton0o

Danno

7000

worntorn

Anonymous

Guest

Danno

Hobot

Torontonian

MikeM

elefantrider

mschmitz57

Hobot

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