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Post by CaptDan on Sept 4, 2009 21:04:00 GMT -5
At the very end of this youtube clip, you can hear this XS’ pipes snarl or “back rap” as he decelerates… www.youtube.com/watch?v=TSgNLODkDzU&feature=relatedDoes anyone else have an XS that snarls when the throttles are snapped shut? Tell me your secret! I LOVE that sound (had an old british sports car that would do it really well), and was wondering what factors in the exhaust cause it to happen. Type of silencer, diameter of headpipe, etc. Thanks! . |
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Post by pamcopete on Sept 5, 2009 5:40:52 GMT -5
CaptDan, That sound is available with "CockTail Shaker" mufflers. I just happen to have a pair available:  PM for details. |
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Post by tomterrific on Sept 5, 2009 11:10:14 GMT -5
Any straight through muffler will "back rap" when the throttle is backed off. The longer the better but it must be straight through. My stock '77 mufflers will make a bit of noise on deceleration because the plug/plate is knocked out of the tube at the end. You can run a broom handle all the way in to the head pipe. Not a true straight through though.
TG
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Post by pamcopete on Sept 5, 2009 11:56:14 GMT -5
Well, those "Cocktail Shakers" are straight through except for a couple of very porous baffles at the end. They definitely have that sound when you back off of the throttle and they have a very cool, deep sound, but they were just too loud for my liking so I took them off after a couple of days. They were brand new when I got them on Ebay. Really great chrome.
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Post by CaptDan on Sept 5, 2009 12:00:25 GMT -5
CaptDan, That sound is available with "CockTail Shaker" mufflers. I just happen to have a pair available: PM for details. Pete, I'd love to make a move for those silencers, but I don't dare add another project to my current ever-growing list. (See "Tonight I’m drinkin’" post for reference. ;D) www.xs650temp.proboards.com/index.cgi?board=General&action=display&thread=13574I will file your info away for the future, though. *thumbsup* ---- Tom, I know the straight-through feature is a major factor, but like in the case of glasspacks (which are straight-through, right?), some bikes/cars do backrap, some don't, like this guy's XS... www.youtube.com/watch?v=U0oKpDMCbBY&feature=relatedI've heard putting glasspacks on "backwards" (?!) will cause backrap. Back in the day, the cholos could get their lowriders to backrap insanely, and they ran some sort of silencer/glasspack. I never figured out how they did it. . |
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Post by tomterrific on Sept 5, 2009 13:12:35 GMT -5
Hmmmm, no back-rap at the rpm recorded. Quieter than I would have expected also. The Cherry Bomb brand has a straight through tube with deep louvers for perforations. The louvers stick inside the core and add a bunch of restriction. Face the louvers toward the engine and the sound is quieter. Face the louvers away from the engine and the exhaust flows much more freely at the expense of being louder. Place a long unrestricted pipe behind the glasspac and it should have the back-off sound.
Tom Graham
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Post by jscribner on Sept 6, 2009 8:02:25 GMT -5
I think Scott's bobber in the video is running straight pipes. I run 1 3/4" headers from MikesXS with the tapered tip mufflers from MikesXS. When I roll off the throttle I get a nice snarl, but not quite that loud. I save it for when I go by someone's house in the morning that I don't particularly like. And I'm with PamCoPete on loud pipes. I got 'em, and I like 'em, but after several hours on my bike my ears ring afterwards. I'm going to start wearing earplugs on long trips.....
John Scribner
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Post by detroitmuscle07 on Sept 6, 2009 9:06:01 GMT -5
Im sporting some of GreatScotts pipes. They definitely snarl BIG TIME on decel!
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Post by xsleo on Sept 6, 2009 23:43:57 GMT -5
On my 75 I knocked out the baffle plate of the stock mufflers with a length of 3/4 inch pipe. They flow better, a bit louder, and on occasion they rap on decceleration. I can hear them over the wind noise at most any speed.
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Post by tomterrific on Sept 7, 2009 9:58:52 GMT -5
Hi Leo,
My '77 has the plate knocked out of the exit tube also. Great sound but not so loud as to be uncivilized. I would not have guessed stock pipes, abet modified, could sound this nice. I heard some early stock 'ball bat' XS mufflers at Mid-Ohio a few years ago and they sounded very sweet, very motorcycle. Fantastic sound.
Tom
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Post by CaptDan on Sept 7, 2009 20:32:51 GMT -5
...I heard some early stock 'ball bat' XS mufflers at Mid-Ohio a few years ago and they sounded very sweet, very motorcycle. Fantastic sound. Honestly, listening to some of those youtube clips of XS sounds has re-fired my desire to get my bike running.  . |
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Post by jamesgs4 on Sept 16, 2009 23:13:21 GMT -5
i run mikes ascot headpipes without mufflers, and it makes that sound as well
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Post by swinewerx on Oct 25, 2009 4:04:23 GMT -5
my pipes are the singles that I removed the muffs and welded in some triamgle pieces for back pressure, I have had the chance to see my craziest chop ridden by someone else besides me, this guy is thew only guy I could find to ride my crazy chop so that I could see what it looks like from a distance. While I rode this one very normal bike he rode my xs, then I kept hearing a very loud and sharp snap that almost sounded like high voltage making contact , I don't ever get worked up or anything ,when we got back I asked him if anything was cracklin'snappin' etc and he said no. Right then I figured out what the wife would always ask me if I was having problems cuz she would always hear the snap also. I guess it is only heard from several car lengths awayand farther
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plattey
Full Member
1982 xs650sj
Posts: 233
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Post by plattey on Feb 15, 2010 0:50:24 GMT -5
Just wanted to share what I found out: I chopped off the stock mufflers and had 1.5" pipe extensions added on and wrapped them in exhaust wrap. When I rev the engine and back off right away, the back-rap is very, very noticable. Then bought internal baffling from JC Whitney and those baffles quieted down the back-rap. Then I made my own internal baffling and the back-rap is a little quieter than the JC-Whitney baffling. Sorry, the sound quality isn't the best, Straightpipes: www.youtube.com/watch?v=4TWqtAQqsaUHomemade baffling: www.youtube.com/watch?v=6tXjc9Bj1IA |
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