My friends custom exhaust 08 yz450

9 replies to this topic
  • Dan_187

Posted June 22, 2008 - 09:26 AM


After being disappointed with the soft power of the stock 08 yz450f. my friend put an 06 muffler on it but cut it down to the size of the 08 (its no louder than an aftermarket can) all i can say is :thumbsup: :p the power on that thing is incredible!! it went from being slower than my 06 to being way snappier and faster. as soon as you crack the throttle on it is takes off, improved power delivery across the entire powerband but mainly down low type snap.

has anyone tried this mod?? it seems almost too much for me haha

  • grayracer513

Posted June 22, 2008 - 11:54 AM


Several have used the '06 silencer, but few have cut it down, and I don't recommend it. The power gains were noted by all who tried it.

  • Markopolo400

Posted June 22, 2008 - 03:42 PM


Did you ride the bike with the 06 silencer before you had it cut?

  • Dan_187

Posted June 22, 2008 - 09:28 PM


Did you ride the bike with the 06 silencer before you had it cut?

no he just cut it down, the power is so snappy that it can be ridden a gear higher in corners

  • qwert321

Posted August 06, 2008 - 03:01 PM


I know this is a old thread but i would like to reserect it. cutting the 06 muffler down would make sense as i read that the head pipe is so big to make up for a shorter exhaust length so this may actually be the hot ticket if you do not replace the header. any thoughts.

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Posted August 06, 2008 - 06:07 PM


gray, why do you not reccomend this mod? please explain- and im guessing this mod will do the same for the 09`s?

  • grayracer513

Posted August 06, 2008 - 07:35 PM


I don't recommend cutting down mufflers because in most cases it does two things; increases noise and decreases power. However, that applies to situations where one starts with a pipe from the bike in question and modifies that. That isn't the case with the situation here, where the muffler being modified is from another bike. Still, it is fundamentally true that shorter straight through glass packed mufflers are louder than long ones, and in the case of the '08 virtually any such muffler will boost the low/mid range power very noticeably. There are a number of threads posted by owners who say exactly that. My advice would be to first try the muffler at full length and go from there.

And of course, once cut, the muffler is cut. There's no practical way to undo it. From the noise standpoint, too many people don't realize that there is a huge difference between what the bike sounds like to the rider and what it sounds like to everyone else. Never decide that your bike is louder or quieter without listening to it as it goes by.

As far as the '09 is concerned, there's no way to know just yet. The exhaust is supposed to have been changed, but right now, I have no details.

  • Ga426owner

Posted August 07, 2008 - 06:53 AM


Agreed it is a waste of time to cut a stock exhaust...and a waste of resale $$ for selling a stock exhaust (uncut)

For god sakes people call Dave at MRD if you want a shorter exhaust......enough of this madness:excuseme:

  • Dan_187

Posted August 07, 2008 - 09:29 AM


I spent the whole last riding session riding this 08 bike so I can give more accurate input on it now. The powerband is shifted lower to more torque and snpa with a bit less top end power, which is fine in my book because you can always shift up and use the potent torque. when i am watching him ride it the bike is no louder than any other bike with an aftermarket can.

This is a very good low cost mod that I would recommend to anyone (although I havent ridden an 08 with an aftermarket can on it)

I like the 08 soo much better than my 06. It feels way more nimble and carves burms way better than my bike. The front wheel feel much more planted and responsive, if you turn the bars the bike will turn easily and hold the line. Plus the low end boost helps me out of tight corners and gets me over jumps. I want one so bad now, either an 08 or 09.


Posted August 07, 2008 - 10:04 PM


09 baby

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