Expansion Chamber Resonance

[Gary Papesh]

Here is how I built mine
YouTube - GPapesh's Channel
I hope this is of use.
Sincerely, Gary P.

 

[foureasy]

Just think, 16-18 hours and you too can have a hand rolled chamber. Cone layout is awesome for.laying out bends. All I use to form the cones is a couple different size pieces of pipe. Then all the faces get belt sanded, then welded with no filler.
thanks goatherder

 

[Black_Moons]

Nah, you don't use cones for hydroforming. I mean I guess you could but the way iv seen it..

You weld two flat sheets togethor in the general shape of your exhaust, curves and all, then just inflate it to be round, Everything strechs.

Euro Spares - FRAME ARTICLE #8 Heres a page that talks about it and has some cool before/after pictures

Note the section about having an inlet and outlet on the exhaust, for letting air out of the pipe, CRITICAL!!!! if a chamber full of compressed air ruptures, its INSANELY DANGERIOUS.
If a chamber full of uncompressable water at high pressure ruptures, Its usally just an annoying leak. But hey, Being all washed up is better then being dead.

 

[foureasy]

Hydroformed pipes look like loop. Rolled cones look much better
Unless of course you have way more than 4000psi. And are willing to make some dies.

 

[foureasy]

Pics of something you've done?

 

[FreeWheeler]

There are plenty of videos of hydroforming with ugly looking results. It's a tempting idea, but hard to control. I can see how to make a die, but that's too much work and materials for one pipe.

Excellent video Gary, thanks for posting that. Time for me to try to mock up some cones that will fit my bike.

 

[FreeWheeler]

I've been trying to mock something up in cardboard and the first couple tries looked like something out of Dr. Seus. I'm trying to preserve the tuned length and each turn burns up length and then there is always some piece of bike in the way. I finally realized that each turn should be made in small lengths and angles. I'll get there eventually.

 

[Gary Papesh]

Try using a program called Cone Layout. It is a slick little shareware gem that is very useful. You input the small and large diameters, angles 1 and 2;which are for each diameter, and the length.The program has 1 window for a 3D real time view of the cone, which you can manipulate to view it, and another window which shows what the flat pattern looks like. Once you have the piece you want, print it out on cardstock, roll and tape it up and Voila, your first cone! I use a protractor to measure how much bend I need, divide that number by the number of pieces I want to use,and divide that number by 2. That will be the angle for each piece. Check it out.
Sincerely, Gary P.

 

[FreeWheeler]

Thanks Gary! I know what you mean about dividing up the angles. The pipe program came with Cone which is almost identical to Cone layout. Getting the first turns was the hard part, now I just need to follow the bikes belly.

Here's what I have so far.

 

[Gary Papesh]

Freewheeler, your pipe is coming along nicely!