Exhaust and muffler

[stevodude]

Bought the OORacing stainless exhaust and a universal muffler, reverse cone, short cafe racer from ebay.

Looks the same as some others have bought off ebay (see attachment image) EXH0030, 17 Inches.

Now out of the box the muffler is extremely loud, and a run to work confirmed it's way to loud and will attract the attention of every policeman within a 2 block radius.

I've pulled apart the muffler and stock it only had abut 2 inches of wadding at the end.

Stupid thing to do today, becuase it is Good Friday, so no motorcycle shops are open today :-(

Has anyone repacked one of these mufflers? and if so how much have you put in it?

 

[ChrisBNE]

I've got that muffler - it was very very loud. I went to a local bike exhaust shop and they put a custom baffle in for $50.00 and it is quieter, still pretty loud, but not offensively so.

 

[Bojer]

Yep , I've got the same one , not much packing in there & after one ride there was hardly any fibreglass left in it .

I repacked with as much fibre as I could but it did not quieten things down that much , in the end I put a 25mm tube welded to a plate in the end to reduce the outlet diameter and as advised by borrachadog get the outlet beyond the reverse cone part that seems to make the noise harsher .

Some people have resorted to pan scourers or wire wool just stuffed in the inlet end - a good option to try when the shops are shut ?! I guess it gets stopped by the screen in the mega and does not seem to reduce performance to any extent .

See page 3 onwards here : http://www.dotheton.com/forum/index.php?topic=56976.30

 

[stevodude]

Great responses, cheers.

Ordered a ceramic fibre roll from the interwebs
started making a 'iner baffle' for the mega end of the muffler.
I have some stainless steel sheet (1mm) and a left over piece of the exhaust pipe ( around 100mm ) should be perfect to make a flange and pipe fitting so the exhaust goes out the end of the pipe past the mega section.

Will post the results (probably take a couple of weeks for the fill to turn up).

Cheers, S.

 

[Tad]

Hi Stevo, I have the same exhaust. was very load, but it can be quietened down by the making of or finding a baffle tube with lots of holes in and then lock wiring as much wadding around as poss. Also like other people have said you need to reduce the outlet size to suit. Hope this helps. Tad.

 

[Novgarod]

I've installed this baffel in the reverse cone muffler, and it sounds and works great! I've also wrapped the perforated part with expanding glass pack. The three center holes are tunable by adding up to three hex screws. This way you redirect the exhaust flow to go trough the outer chamber and the outer outlets. Giving a bit more back pressure and a lower exhaust note.

 

[stevodude]

I've found a stainless table leg from bunnings for $3 that I have adjusted to fit my reverse cone exhaust nicely. I have also ordered a bunch of ceramic fibre sheet from ebay ( I ordered in bulk so it was cheap-ish) well... cheap per meter, but I ordered 7 meters lol. I know have enough for about 20 mufflers, which I will offer the local bike guys to repack their exhausts for a small fee of course.

Fibre has turned up today, so I have some modifications to complete on the weekend.
remove the original black exhaust and muffler
install stainless exhaust & modified muffler.
Install my main jet that I drilled out to around 105 (it was an 82 or something),
Hopefully will run ok with airbox on, but I may have to remove airbox also to gain the extra air from the jet I made.

S.

 

[josephau]

hey steve

still looking for ways to completely secure my reverse cone muffler. do u have a pic of u using the table leg tk fix urs?

joseph

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[stevodude]

Will snap some pictures this weekend as I didn't get much of a chance to play with the bikes in the weekend just gone.

 

[josephau]

Thx mate


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[stevodude]

Sorry, I got carried away and put it all together without taking any pics...

I got one of these: http://www.bunnings.com.au/leg-furniture-metal-leggz-30x150mm-brshd-ni-rnd-lz00979_p3940133
Cut it at around 50mm from the flange (so it is flush with the end of the muffler (or sticking out about 3mm past the end), drilled a 20mm hole in the flange end.
Pop rivet it to the central muffler bit (with the holes) so pointing out the back (back to back)
filled the muffler with dense ceramic fibre ( used for lining pottery kilns ).

put it all together and I found that it was still a little noise (must be air escaping around the muffler and reverberating in the cone end.

so I then found a piece of 1mm think wall tube 50mm diameter and cut off a length about 52mm long to fit just on the inside tip of the cone and rest against the pop rivet end. filled this outside of the tube and in the cavity of the tip and screwed that in.

I think it's almost perfect, not too loud, but has a 'plumpy' little sound

Tried to do a paint image of the structure lol...

 

[cafe59]

Spend whole afternoon digging the bloody cat out. Was soo happy when the last bit of the bastard came out! Putting a muffler and a baffle I bought on ebay on tomorrow, will post some pics as well.

 

[ChrisBNE]

Spend whole afternoon digging the bloody cat out. Was soo happy when the last bit of the bastard came out! Putting a muffler and a baffle I bought on ebay on tomorrow, will post some pics as well.

Yeah, that is a good feeling!

 

[cafe59]

Right... so the muffler and OORacing air filter fitted! I have used a baffle off eBay (around $20), wrapped it in some fiberglass muffler packing material and then put the muffler on. It's still quite loud, but I love the sound. Kind of deep, bass - exactly how a cafe racer should sound like! I might have to get the baffle weld to the pipe, I kind of just shoved the baffle in, so I am worried that it might loosen up over time.

I struggled to find how to fit the mounting bracket to the frame. The way I did it doesn't look very good, but at least it's secure. Any ideas how to do it better?

All in all I am very pleased with the increased performance of the bike! It goes well and sounds great! Big smile on my face after today's ride ;-)

 

[musket the dog]

I struggled to find how to fit the mounting bracket to the frame. The way I did it doesn't look very good, but at least it's secure. Any ideas how to do it better?

Would it be possible to rotate the silencer around so the bracket is on the back? Mine has the same type of bracket, I just had to swing the downpipe out a bit more.

 

[ChrisBNE]

Same fitting on mine. I bent the mounting piece in an S shape and its fits well now.

 

[cafe59]

Would it be possible to rotate the silencer around so the bracket is on the back?

I have tried that, but then the muffler is too far away from the frame...

I bent the mounting piece in an S shape

Yep that was what I was thinking about! Could you post/pm me a close up picture please?

Cheers,

Thomas

 

[ChrisBNE]

There you go

 

[cafe59]

There you go

Thanks Chris!

 

[stevodude]

Ah good idea. I have mine on straight, but I cannot use the rear brake pedal.
Mind you the rear brake is 100% useless anyway lol.

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