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Discussion Starter #1
Has anyone considered what might be done to the factory exhaust to make it a little (or a lot) louder? For the sake of avoiding a forum war I am not concerned with the right or wrong aspect of a loud pipe and I can't spent much cash. I have a saw, dremmel and a need for noise.

My ideas thus far;

- using a dremmel and cutting a 'window' underneath somewhere

- cutting the cat and muffler off completely then having some kind of shorty pipe welded on

- using some kind of magic to make the inner workings of the muffler and cat just go away

help!
 

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FYI if you do that you will need some sort of fuel management otherwise you will be lean and bike will run like crap
 

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Discussion Starter #3
Then you have saved me from my own stupidity.

How will aftermarket pipes overcome this same issue?


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Doesn't the sensor on the pipe ( O2 sensor? ) allow the computer to adjust the mixture?
on bikes, the o2 sensor (closed loop) is used only to lean out the fuel mixture under low load conditions (i.e. highway cruising) for increased fuel economy and lower emissions. everywhere else, the ecu is running in alpha-n open loop mode.

motorcycle engine management systems are years behind those found in cars.
 

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FZ muffler.jpg Bodypilot, since you're in California, I wouldn't dare do either option 1 or 2 with all the emissions laws that you have to deal with. I could see that causing a big problem for you, NO WAY would I consider removing the catalytic converter!

That said, I've been considering option 3 myself. I want to essentially split the muffler case along the welds, and modify the baffling on the inside for some more sound. Cutting along the green lines you see in the picture. The red outline shows where something is welded inside the case, whether it's baffling or the cat I don't know yet, but it's only on the top section so it shouldn't be an obstacle. I'm basically just un-doing the last step in the production process.

Anyway, the plan is to remove the bottom and then modify the baffling, while retaining the catalytic converter for emissions. I'll seriously do this to your muffler for free (I might need a small amount to help cover the TIG welding gas and filler rod), the only real cost to you is shipping both ways. Just be aware that you will be the guinea pig. I'll post pictures of how it looks on the inside on the forum, and you tell me what you want me to do to it.

Let me know what you think, once it's welded back up it'll look the same as stock to the emissions inspector, just louder. All I want is your feedback on how it sounds, so I know what I want to do to mine. :cool:
 

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Discussion Starter #9
View attachment 555 Bodypilot, since you're in California, I wouldn't dare do either option 1 or 2 with all the emissions laws that you have to deal with. I could see that causing a big problem for you, NO WAY would I consider removing the cat
Your offer is very much appreciated - thank you:) I have no welding-fu so option 3 was realistically a dream only for me. I am not sure that the emissions laws really matter here as AFIK there is no smog test for a motorcycle once registered, yes the manufacturer has to make the design pass but then it's up to the owner to 'maintain' it.

If what I think is in fact the case can the core of the cat be made to go away as well?

From the feedback above and look on other forums it looks like some kind of change is needed to the fuel system or the bike will indeed run lean. There is a chap called Marthy on another FX forum that is working that out.
 

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I just looked Marthy's exhaust up, that does sound pretty nice. I'm kind of feeling inspired by it actually, he he :)

Bodypilot, if you take me up on my offer I'll modify the interior however you'd like, including removing the cat if that's what you want. But I assume no legal responsibility, lol :eek:

I've just seen the emissions laws that car owners have to put up with, for example how any aftermarket exhaust system has to be C.A.R.B compliant. I have no idea what the laws are for motorcycles, but I wouldn't be surprised if they have similar restrictions soon... I don't know though. Proceed at your own risk right? If emissions tests are ever required, you'll be screwed without the cat.
 

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Whats up guys! I just sign up snd people are already talking about me! LOL

Here's a nice pic for you...

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DUDE, you have been hanging out with the wrong crowd, but who am I to talk. I run with the freaks and geeks.
 

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Not true... Modding the exhaust is going to affect the engines volumetric efficiency, which in turn means the fuel mapping needs to be modified. Keep in mind that not only will reduced back pressure affect VE, but changing the length of the exhaust system makes a huge difference too, not to mention diameters... There are a lot of variables at play.

Also, I'm pretty sure the o2 sensor is just used in Eco mode, and the ecu resorts to preset maps under harder acceleration than that. But I could be wrong.
 
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