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Inside the FJ muffler


papac2000
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20150221_101410_zps1c6cb428.jpg
20150221_103255_zps8c051215.jpg
 
Cut open a panel on the top into the rear chamber behind the mount. Removing this section of pipe allows gasses to exit without going back to the front and returning through a glasspacked tube (S shaped).
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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There are more aggressive ways to do this, and I thought about it. This method is the quick and easy. I considered adding a second tube to the divider/baffle from the second chamber (cat area) into the rear chamber ( like the one located top center) as well as putting a larger outlet. I think that would be the ultimate without getting crazy. That would maintain the cat and still increase sound and also flow. I've left the stock tip for now. I haven't ridden it yet, and may try that AFTER the 1000km check at the dealer.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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I knew the hp would change little to none. In my mind this mod was always about the sound. The bike has more power than I'll be able to use as it is. The change was +1hp and tq was essentially unchanged. I was just hoping not to decrease power with this experiment. ...lol. If I try the "more aggressive" version I will redyno. I suspect it would work a bit better.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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20150221_103300_zps0b2ee8ed.jpg
Rear chamber with S bend removed. Stock muffler is 3 chambered. Exhaust exits the cat and enters the middle chamber and then into the rear chamber through the top tube. Normally it would then be forced back to the front chamber through the bottom tube and then turn around and travel back through a glass packed tube on the left and out through the S bend outlet.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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I knew the hp would change little to none. In my mind this mod was always about the sound. The bike has more power than I'll be able to use as it is. The change was +1hp and tq was essentially unchanged. I was just hoping not to decrease power with this experiment. ...lol. If I try the "more aggressive" version I will redyno. I suspect it would work a bit better.
Thanks for doing this, and documenting it.  While this mod isn't something I would do (I'm a big fan of the stealthy stock pipes--I like my speed to be as invisible as possible), it is a cheap option for people who want more sound, and the dyno pull and numbers show that at least it doesn't cause a power dip.
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The change in sound on this rendition is very modest. For those after a more dramatic change, I suggest the second tube through the baffle and the bigger outlet.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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Great discovery papac.
Could you have cut down the S tube to match the position of the pipe inlet from the header and seam weld it back to the outlet pipe? Granted, you would only get to seam weld it over half way round the join. You wouldn't need to weld it to the pipe inlet. Just very close to it.
Could you try that? Did you investigate which is the inlet pipe from the header? Sorry, you did say the top tube!
Cheers,
Steve
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I had someone suggest that at my shop today Steve. As I mentioned, there are a few ways you could do this. I wanted to have the whole internal volume available to keep a deeper tone and connecting those together would cut the volume of air/gasses considerably. It might flow better though.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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Fantastic, I need to listen to the sound now.
A government which robs Peter to pay Paul can always depend on the support of Paul.
George Bernard Shaw (1856-1950)
Bikes:
2015 FJ-09, Seat Concepts seat cover and foam, Cal Sci medium screen, rim stripes, factory heated grips, Cortech Dryver tank bag ring, Modified stock exhaust, FlashTune with Graves fuel map, Cree driving lights, Aux power socket.
2012 Street Triple type R (Wifes)
2007 FJR1300 (Sold!)
 
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Fantastic, I need to listen to the sound now.
 
I will try to make another vid just idling and a few revs. The dyno video is doesn't get the idea across I know.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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I had someone suggest that at my shop today Steve. As I mentioned, there are a few ways you could do this. I wanted to have the whole internal volume available to keep a deeper tone and connecting those together would cut the volume of air/gasses considerably. It might flow better though.
It may also make it sound very loud too! Either way papac, good work!
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I had someone suggest that at my shop today Steve. As I mentioned, there are a few ways you could do this. I wanted to have the whole internal volume available to keep a deeper tone and connecting those together would cut the volume of air/gasses considerably. It might flow better though.
It may also make it sound very loud too! Either way papac, good work!
 
That was my concern...although I think with my current version there is room for more sound yet.
2015 Matte Grey
Modded stock exhaust, modded stock screen, modded stock seat, OEM heated grips, LED indicators, FlashTuned ECU, ZX10R shock
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I imbedded one of your pictures in the first post, I hope that was ok?
A government which robs Peter to pay Paul can always depend on the support of Paul.
George Bernard Shaw (1856-1950)
Bikes:
2015 FJ-09, Seat Concepts seat cover and foam, Cal Sci medium screen, rim stripes, factory heated grips, Cortech Dryver tank bag ring, Modified stock exhaust, FlashTune with Graves fuel map, Cree driving lights, Aux power socket.
2012 Street Triple type R (Wifes)
2007 FJR1300 (Sold!)
 
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