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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Mon May 06, 2019 8:59 am Post subject: Re-packing muffler cans |
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I know that there’s nothing too technical about re-packing an exhaust can, but I’m just after advice regarding how packing a muffler differently will alter the sound level and note of an exhaust system.
I finally got around to fitting a race exhaust system that I bought a while ago for my SB6. My intention was to simply get some more noise out of it rather than chasing performance as the stock SB6 system is very quiet. When I bought the system from a member on here, the seller told me that it was too loud for him..... well I can confirm, it is very loud and sounds tinny. It has no packing in it at all and I think the sound is echoing in the empty aluminium cans.
I want it loud but not too loud and not tinny. I’m just wondering if there is a method of packing the mufflers or partly packing the mufflers that will achieve this?
Any ideas? _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Mon May 06, 2019 9:18 am Post subject: |
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_________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Mon May 06, 2019 9:22 am Post subject: |
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It looks like a stock system to me but it bolts together rather than being rivitted together and it has a Plate on it saying ‘for race use only’ _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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GeeKay
Joined: 29 May 2009 Posts: 1767 Location: West Yorkshire
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Posted: Mon May 06, 2019 10:02 am Post subject: |
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for my 2-strokes I buy exhaust wadding off ebay, wrap it around the baffle tubes and secure with stainless wire (the stuff used for lock-wiring race bikes). How much you wrap it determines the noise level (to some extent). _________________ Bimota SB6 and Benelli TNT 899S road bikes.
Beta Techno trials iron. Project bikes:- Suzuki V4 500, TS185 cafe racer, XR11/71, Kettle/Katana, TDRGV250, OR50, Gag125,Triumph T595 and a Triumph X75 Hurricane replica.
Too many projects............... |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Mon May 06, 2019 11:36 am Post subject: |
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As per Geekay.....When I bought my New FMF Gnarly end can for my KDX...it was immediately noisier...but not too noisey….as it was a straight thru end can....instructions said re-apck after every 20 hrs of use....meaning....after 20 Hrs it will get noisier....as the material gets soaked with exhaust products and its sound deadening performance diminishes.....My interpretation was …."use for 20 hrs and the true sound will come through and just get better and better after that if you dont repack....and I can confirm that to be the case......Thus yes...it will stop the tinny ring sound.....and as it gets coked up the straight thru principle will increase as gases are like water...they take the path of least resistance in their efforts to escape......thus when new they will go into the material but this will get less and less |
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Bud977
Joined: 03 Mar 2013 Posts: 525 Location: Sydney
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Posted: Mon May 06, 2019 9:57 pm Post subject: |
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The packing deteriorates quicker in a two stroke like the KDX because it get soaked in two stroke oil splooge, making it effectively solid.
So it lasts much longer than 20 hours in a 4 stroke.
So Brian, I'd pack some of that exhaust wadding in there and it will do the job.
Quite an unusual looking pipe for a race pipe. 4-2-1 pipes are usually a mid range pipe, the junctions and pipe sizes?? |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Mon May 06, 2019 10:13 pm Post subject: |
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Bud977 wrote: |
The packing deteriorates quicker in a two stroke like the KDX because it get soaked in two stroke oil splooge, making it effectively solid.
So it lasts much longer than 20 hours in a 4 stroke.
So Brian, I'd pack some of that exhaust wadding in there and it will do the job.
Quite an unusual looking pipe for a race pipe. 4-2-1 pipes are usually a mid range pipe, the junctions and pipe sizes?? |
I do like "splooge"....Or Gook or splurge its often referred to...but yeh...I concur....I just didn't have any knowledge of packing 4-stroke exhaust cans to offer.... |
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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Mon May 06, 2019 10:42 pm Post subject: |
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Thanks for the replies fellas. I’ll buy some wadding and do some experimenting. It’s not too much trouble to pull apart so I might try a couple different ideas _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Tue May 07, 2019 9:00 am Post subject: Re: Re-packing muffler cans |
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brian wrote: |
..... well I can confirm, it is very loud and sounds tinny. It has no packing in it at all and I think the sound is echoing in the empty aluminium cans.
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In fact.... I think the fookin thing is LOUDER with the mufflers on than it is with just the headers pipes on and the mufflers off _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Tue May 07, 2019 9:49 am Post subject: |
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If the mufflers have no wadding then its the acoustics effect of it resonating around the baffles evidently....that'll lessen with wadding ...just make sure you buy the right stuff thats fire retardant....I wont ever buy Ram air foam filters since I've heard and seen the horror stories of allegedly "fake" versions being sold...that catch fire.... |
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rpo83
Joined: 28 Oct 2008 Posts: 387 Location: Melbourne, Australia
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Posted: Tue May 07, 2019 9:51 am Post subject: |
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When i pulled my mufflers apart to get them polished, i repacked them lightly with 2 stroke muffler packing, It is widely available from most bike shops. _________________ Cheers
Steve
YB5 #130, YB5 #196, YB7 #302, SB6 #949, Laverda RGS Executive, Laverda RGS Corsa. |
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Evilchicken0
Joined: 12 May 2010 Posts: 2996 Location: London
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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Tue May 07, 2019 11:09 pm Post subject: |
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Thanks again fellas for the comments.
I’m still not sure how to control the amount of ‘loudness’ that the mufflers produce using the packing. I’m assuming that the packing will need to be tightly packed between the baffle tube and the outer can otherwise it will come loose and disintegrate? I’m also assuming that if it’s tightly packed then it will be quite? Is it possible to pack it with strips of packing leaving gaps between the strips of packing along the length of the can? I’m guessing not as this will come loose as well. Will it be louder if it’s wrapped more loosely? _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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brian
Joined: 22 Aug 2011 Posts: 3772 Location: Australia
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Posted: Tue May 07, 2019 11:12 pm Post subject: |
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Do you think the stock mufflers would be the same inside as these ‘race’ mufflers? Meaning, will the stock mufflers have a straight through baffle or a different series of baffles to make them more quiet? If that’s the case then simply packing these ‘race’ cans tightly may give me the result that I want..... loud but not offensively loud and tinny. _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Tue May 07, 2019 11:32 pm Post subject: |
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A lot of "modern" 4 stroke end cans come with removable baffles....which is basically a cone inserted into the end with a flat plate on it that takes impact of exhaust gases and slows its exit...or diverts it around something to again slow it down...and when removed its classed as "straight through"...i.e. you can poke a stick the full length down until it hits a bend in the pipes after the end can....other large end cans can have cats in them.....more blockages...or fixed diversion plates to again slow....like putting your hand over the bell end of a trumpet to quieten it.... |
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