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450r muffler
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Posted by: MY FYN 79

I've asked some people this before, and I trust their thoughts. I'm just looking for more opinions.

How much more does a stock 450r muffler flow than a stock 300ex one? Its not even about the money of buying a slip on like an HMF for my 300ex, its more about the fact I dont want a loud quad. I already have an aftermarket header, and also a friend who does a lot of Tig welding work on stainless. A 450r muffler can be had shipped off Ebay for about $30.00.

My original plan (and I'm still considering it) was/is to run the stock muffler with an aftermarket header. The motor is going to consist of a .120 overbore, 11 to 1, Stage 1 hotcam, 400ex carb and the header. Knowing I would sacrifice the power of not using a slip-on, would a 450r (or different) stock muffler be a little bit of an improvement?

Posted by: chumbini

I have asked the same question so many times but no one replys. I did read on here about someone using a 400ex muffler on a modified 300ex to improve power and keep the sound levels down. I think like you. I purchased a 450r headpipe and muffler off of eBay. The headpipe is a no go but I have a white Bros pipe anyway. You have to cut and reweld the inlet but I think it is perfect for what you want. I am in the process because I live in a residential area and don't want complaints from neighbors or police. If you think about the 450r being Honda's racebike, although they released a 700 this year, it definitely has to be a performance muffler. 282cc (300ex) into a muffler designed for 450cc . It makes sense to me. Also, the 450r muffler is tuneable. You can remove the spark arrestor and change the end caps to play with the sound/backpressure.. I read somewhere on here that the 300ex stock muffler is seriously restrictive. I hope this helps. i will post my results when completed.

Posted by: Sjorge300EX

improvment......yes. More than if you were to use a real exhaust. no.

If you are interested i have a stock 450r muffler fom a 05 that has about 30 hours on it.

Posted by: MY FYN 79

Thanks for the replies guys, and sorry for the slow response.

I totally understand that the 450r muffler isnt going to show gains like an aftermarket one will, but seeing as I'd be willing to run the 300 stocker muff, anything is a step in the right direction. I'll update this when I get r dun!

Posted by: chumbini

Wll it's done. It looks sweet and sounds sweet. If any one is interested I can forward the pictures. I changed some of the mounts but the only real welding came from cutting off the large inlet and welding in the new piece I cut off of the 450R headpipe. My quad seems much more responsive and its very quiet. I still have the spark arrestor in the muffler. I will evaluate it this way and without the arrestor. Everything fits and it looks factory. It can be done and it will look great.. I got a performance boost and it's not gonna upset my neighbors the way some of the other quads do . We now have a police quad team that responds when loud quads are operating so I do not need a fine or to alert anyone. PS I have a white Bros Stainless headpipe that I also used on the install.

Posted by: MY FYN 79

Awesome man!

Send some pictures my way if you could.

TPI79MC@aol.com

Thanks!

Posted by: Grizzly_A

I'd like some pictures also. Please!

YOu have a PM

Posted by: andre7276

i would like to see pics blueeyzjr@msn.com

Posted by: MY FYN 79

Just figured I'd update this and show the finished product. We got the motor together this afternoon and I got the exhaust figured out this evening. Its an aftermarket headpipe of some kind, with a factory 450r muffler. I still have to clean up a few cuts on the muffler and weld on 1 more mount, but it turned out much nicer than I thought.

http://memimage.cardomain.net/member_images/6/web/438000-438999/438326_437_full.jpg

http://memimage.cardomain.net/member_images/6/web/438000-438999/438326_436_full.jpg

http://memimage.cardomain.net/member_images/6/web/438000-438999/438326_438_full.jpg

Not a very tough project at all, just gotta make sure your measurements are correct before cutting.

Posted by: chumbini

looks great. See how easy it is. Polish up the muffler with 000 stainless steel wool and it will really shine like mine does. Let me know what you think of the sound and power. i am very happy with mine.

Posted by: honda300EXtreme

looks good man, nice job,,

man that header looks fimiliar?

but i am gonna need a ride report