stock pipe modding

[Hondamaster5505]

well, wiith the 400, theres an open space in the pipe about 6in long until theres a wall w. a small hole where the chambers begin. Do you think, if i drill a couple decent size holes deep enough in, that it will be a little free'er flowing then if it had to go through all the chambers completely to get to the open space? they would be in the pipe, im not drilling out the sides, cuz thats stupid. and between that and removing the baffle, would it make a difference

[honda300EXtreme]

i wouldnt worry about all the drilling.... i mean you can if ya want to, but if you want to flow some more air out i would just remove the baffle,

[Got Boost]

buy an aftermarket slip on, I tried the gutted stock exhaust for a while, and evertime I rode it you couldn't help but hit the rev limiter, and it ran like shat, I put on a slip on and it made a huge difference in how it ran, and some power gain.

[Hondamaster5505]

well, see, i wasnt talking bout gutting it, but in ur case, u kinda screwed up, no offense.

What you should've done was:
1. Gut the pipe
2. Buy a mesh-type material
and make it into a 2in circle
3. Insert mesh
4. Fill the area around the mesh with silencer packing
Then its not too free flowing

The way you had it, its almost 6in of open space, which is too free flowing so u have almost no back pressure, resulting in lower compression, which is why the motor ran like $hit

[Got Boost]

I got that, in my opinion you couldn't make a stock silencer up to par with a low end silencer, I have seen what you are doing, it sounds throaty, but the performance isn't all there. But all the power to you for trying to save a buck and customize your own stuff, that is awsome. I have a custom fab in process, I am trying to make a drag exhaust, just for fun, all that I know is it is loud.

[400exBRAAP]

how is that drag silencer coming along? lets see some pics of it

[Hondamaster5505]

well im trying to find a stock exhaust pipe to do it with, someone who will give it to me for free or barely anything because i dont have money to spare..
If not i will have to wait till i get some extra money to get the pipe+materials. Being 14, money is hard to come by.

And to the guy that said its not gonna be as good as a low-end silencer:
I saw an HMF on one the other day, and studied it.
Its not much more than a 2in hole all the way back with packing all around it. The only defect of the stock pipe idea, is weight an looks, i would custom paint it, but it aint gonna be no candy-red HMF. lol.

When i do it, if it works good, ill start makin and selling em as HMF replicas.

[XXXRACER165]

But what about the spark arrestor?

[Hondamaster5505]

??what??

I would also be cutting the baffle out of the tip to match the rest of the pipe, so it would be like a full preformance muffler, 2in all the way back.

I might use a screen-type s/a, just i piece of mesh or something that goes where the tip bolts on. Thats what those aftermarket tips use.

[XXXRACER165]

Ohh I see, but your going to go through a lot of trouble trying to get the DNR or USFS to approve of your spark arrestor. If your riding on a state trail and get busted for not having a approved s/a you get a hefty fine.

[Hondamaster5505]

Originally posted by XXXRACER165
Ohh I see, but your going to go through a lot of trouble trying to get the DNR or USFS to approve of your spark arrestor. If your riding on a state trail and get busted for not having a approved s/a you get a hefty fine.

Even though this pipe wouldnt be for me, (because i already have a dmc full system) i dont ride on state trails anyway. we mainly ride at coal mines and so on..

And believe me, i would tell people that before they would buy it. Because they should know it anyway, being its a home-made custom pipe.
And the ones they sell with the tips on ebay, they come with the same exact thing, and say its USFS approved??

so i figured it might.

And those guys on ebay are lying scumbags. They say they are power tips and with jetting it will add 15-20% power.
BULL!!
I already proved that wrong, they are selling tips with the baffles cut out of them for $40!!

[dariusld]

Old link (http://home.earthlink.net/~gellett/exhaust/index.htm)

[XXXRACER165]

Nice Pic

yeah the chambers are half a** they could have made such a better design

[honda300EXtreme]

i just dont see any purpose in rebulding a 400 slip on, i mean its a good thought and you have ambition so you can direct your thoguhts in another direction and maybe totally fab your own exhaust system


i personally dont think any way you rebuild the pipe will result in much gain, mainly because the muffler body its self is still heavy, and alot of exhaust gain power through a stepped mid pipe design which the 400ex muffler does not have...


thats my 0.02