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I'm with you, Steve. Crazy loud exhaust noise on our lovely CBRs is like that loud Texan who is all hat and no cattle. Tried a mod on my Yoshi by constricting the very inside end of the "low volume insert" pipe by cutting inch long cuts every 1/4 inch and then folding the ends together to narrow the inlet opeing tp about 1" in diameter , and...like with your experience, it got even louder and raspier. So I straightened it all back to near original. Back to square one. If it wasn't for the fact that the funky looking (cast iron heavy) stock pipe is soooo silent, I am almost tempted to refit it.
 

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I'm on the boat with re-installing the stocker as well. I'll try the quiet tip and packing and if I'm not happy with the results I'll put the stocker back on and sell the 2Bros.

If I could get a sound half way between the 2 Bros and the Stocker, I'd be one happy camper. As it is, the 2 Bros is embarrassing and downright inconsiderate first thing in the morning to my neighbours.

Though for some reason this afternoon when I had some stuff to do at lunch it seemed to have toned itself down some. Most pipes do that, but not usually until you have 5000 or so miles on them.
 

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Remove cat

I am tempted to try removing the catalyst by breaking it up with a chisel up from the inlet as an in between step to see what happens. This is obviously an irreversible test but may give a good horsepower increase. The other allure of a good slip on is ridding 15 pounds off of the bike but I am not willing to ride something that is so loud that I am causing trouble.
 

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Just a little update. I realized after I posted my last reply that I'd be happier with the sewing machine sound so I put the stocker back on after work tonight. I'm going to repack the the 2Bro's and order the P1X tip (supposed to be 7db quieter).

If that doesn't tone it down enough, it'll be for sale.

As for power, their is no discernable difference between it and the stocker, it just sounds faster. But it does look sweet!
 

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Just in case anybody else wants to try it. Here's the sound mod. The thumbscrew (picked up at Lowe's for a $1.50) is in at about a 45 degree angle. 90 degrees I swear it made it louder! But at 45 it definitely knocked it down a couple of db.

 

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I'm going to repack the the 2Bro's and order the P1X tip (supposed to be 7db quieter).

If that doesn't tone it down enough, it'll be for sale.

As for power, their is no discernable difference between it and the stocker, it just sounds faster. But it does look sweet!
The quieter of their two available tips is supposed to be 7db quieter than the open pipe. It is only 2db quieter than what you have now.
 

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Let us know if the p1x tip is any different. I love the way the bike sounds at about 3000 to 5000rpm when you are just cruising, But it does get pretty loud when you are above that.
 

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Sheet metal

Just a little update. I realized after I posted my last reply that I'd be happier with the sewing machine sound so I put the stocker back on after work tonight. I'm going to repack the the 2Bro's and order the P1X tip (supposed to be 7db quieter).

If that doesn't tone it down enough, it'll be for sale
Another idea to reduce the sound level: Cut a piece of sheet metal to a width that matches the inside diameter of the muffler. Put a twist into it as much as possible. And wind it down into the muffler all the way from the in to the out so that the silencer insert presses it tight. This would effectively make the muffler a little longer and a little smaller in cross area.
 

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Update. Picked up some more 4 stroke packing and drilled out the rivets on my brand new exhaust (gulp). Long story short. It's packed tight from the factory. A layer of steel wool surrounds the baffle, followed by a thick layer of fiberglass. Those rumours of 2 Bros. cans being lightly packed from the factory don't seem to be true any longer.

I couldn't stuff another ounce of packing in their if I tried.

So that only leaves the P1X tip and any mod we can come up with to shut the thing up some! I'll snap some pics before I button it back up.
 

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what do you guys think about adding a spark arrester as well as having the p1x tip. I know when i took the spark arrester out of my pro circuit pipe on my dirt bike it made it a lot louder.
 

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I also know of another old school chopper mod (my past is coming through isn't it..)

A dishwasher strainer. Maybe something out of bar sink would fit. It'll introduce a lot of back pressure though so you have to tune it with some 'Speed Holes'.

I'll see how the tip P1X tip does and if it doesn't tame the bark enough. I'll try the dishwasher mod.

Oh ya, when re-assembling your 2Bros from packing, don't forget the little trim pieces that go under the rivets. Serves me right for doing it first thing in the AM.
 

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Not sure if tighter fiberglass packing or loose would be quieter, Steve. Logic would say loose packing. I never stuffed a muffler, so what do I know. The Yoshi "low volume" insert reduces the bark level only a very small amount on my bike. Curious to see how how the P1X tip works for you. I was holding the the cast iron stock pipe in my hands psyching myself up to replace the beautiful Yoshi...I couldn't do it. I'll be riding with earplugs and pissing off neighbors untill "we", collectively speaking, find a quiet solution to our loud pipes.

Mike
 

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Not sure if tighter fiberglass packing or loose would be quieter, Steve. Logic would say loose packing. I never stuffed a muffler, so what do I know.

I'll be riding with earplugs and pissing off neighbors untill "we", collectively speaking, find a quiet solution to our loud pipes.
I've repacked my dirt bike exhausts and tight is good. Especially with power pulses from a single - it plays havoc with packing. if it's loose, it won't last long.

I found a strainer for a bar sink online at home depot that should fit with some massaging. Shame it's a holiday today in Canada (Labour Day) as today would've been perfect to try it.

I expect the P1X tip to be delivered in about 10 days. Stay tuna'd.
 

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P1X tip came in pronto. Got it installed and the can back on the bike. Save your money. It's 'slightly' quieter at idle, no diff anywhere else. So, now, plan C.
 

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It's beginning to appear as though we are looking for something which does not exist.

Two Bros, Yoshi, M4, Jardine, et. al., are you listening? Or are your ears ringing too much from all those racetrack slip-ons and fulls?
 

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If what i see online is right..$350 for the yoshi slipon.......$550 or more for the two bothers?
I think i just answered your question :)

Unless money isnt an issue with you...in that case I have seen many other exhausts besides just those 2 that have came out in the past month or so for the 2011 cbr250r....do an internet search
Two Bros is about the same price. $330 for aluminum-410 for carbon.
 
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