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Discussion Starter #1
Im thinking of going back to the stock muffler. Why? Im tired of the drone. Previous owner cut the stock system up to fit a slip on. They gave me aftermarket headers.

But I cant get a muffler on it that isnt stupid loud. One on the bike has 2 baffles in it.

So what Im thinking is matching the stock muffler up to the aftermarket headers.

So will I lose much power?
 

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All anyone can do is guess! If you figure the average fz with stock exhaust is about 105 hp give or take a pony or so either way, and one with an aftermarket exhaust and flash might ad 8 to10% in most cases...then yes you will lose a bit. Depending on how you ride you probably wont find that to be a big deal.
 

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I would think decatting plays a role in hp gain. Assuming your catalytic converter has been removed, replacing the new muffler with a factory can might put the horsepower somewhere in between the other two setups.

Regarding fitup of the factory muffler to your custom header, if it looks like the same approximate placement as the new muffler, it should be an easy swap.
 

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Discussion Starter #6
I would think decatting plays a role in hp gain. Assuming your catalytic converter has been removed, replacing the new muffler with a factory can might put the horsepower somewhere in between the other two setups.

Regarding fitup of the factory muffler to your custom header, if it looks like the same approximate placement as the new muffler, it should be an easy swap.
The cat in these are huge. Biggest I have seen on a bike. I think it will flow power fine. Guys on FJ forums have been getting 112hp with a modded stocker. I have cut open its bottom and created a trap door from the middle chamber to the front one. Idea of that is to give it more flow without making it straight through. Im also putting in a 2" outlet.

Yes I just need to get my hands on some 2" pipe to weld it on.

this is where you get to educate all of us, do a pre and post dyno run if you have access to a dyno
I could but dyno time here is very expensive. It will be going on for a flash so we will see the end result. Am modding the stock Cat as well. Want more flow with a little more noise than stock.

Purchase a nice aftermarket exhaust and run it with the baffle in. This will kill the noise, keep perfomance, and add a nice looking system.
Here a good pipe is $1900. No thanks.
 

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The cat in these are huge. Biggest I have seen on a bike. I think it will flow power fine. Guys on FJ forums have been getting 112hp with a modded stocker. I have cut open its bottom and created a trap door from the middle chamber to the front one. Idea of that is to give it more flow without making it straight through. Im also putting in a 2" outlet.

Yes I just need to get my hands on some 2" pipe to weld it on.



I could but dyno time here is very expensive. It will be going on for a flash so we will see the end result. Am modding the stock Cat as well. Want more flow with a little more noise than stock.



Here a good pipe is $1900. No thanks.
This might not help, but I was quoted $1700 for a full system from Yamaha.
 

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If I'm not mistaken there are two Akra carbons for sale in the classifieds. I hear those with a baffle in are pretty quiet.
 

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Well its on. Perfect fit. Had to undo the headers so I could swing the muffler on.

Sound is exactly what i wanted. Muted but still rowdy when getting on it. Yes I did a small mod inside it and changed the outlet to 1 3/4.

What I didnt expect was how much more power it has on the bottom. Wow that other system must have been killing it.

Very happy.
 

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Well its on. Perfect fit. Had to undo the headers so I could swing the muffler on.

Sound is exactly what i wanted. Muted but still rowdy when getting on it. Yes I did a small mod inside it and changed the outlet to 1 3/4.

What I didnt expect was how much more power it has on the bottom. Wow that other system must have been killing it.

Very happy.
Interesting. I don't suppose you took pics of the surgery?
 

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Discussion Starter #13
Interesting. I don't suppose you took pics of the surgery?
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So I the bottom i cut it open and notched the wall so it exits into the front chamber. My thinking was this will create more flow with less noise. Then changed the outlet to 1.75". Seems to have worked very well.

Lots more yummy power.
 
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