Author Topic: Pipe Guts (Read 2113 times)

ash · « **on:** February 23, 2006, 06:48:20 PM »

I've worked plenty with speed and motorcycle pipes, but they have no internal baffles. So what does a baffled stunt pipe look like inside?

I can't imagine how they would be arranged so as to not impede the return reflections. Anyone have pictures or links illustrating the principle?

phil c · « **Reply #1 on:** February 24, 2006, 11:50:41 AM »

look through Martin's site and learn more than you wanted to know.

http://www.mh-aerotools.de/airfoils/

ash · « **Reply #2 on:** February 24, 2006, 06:26:53 PM »

Thanks for that Phil. Still not more than I wanted to know

Just call me a sponge

The picture on the JavaPipe page illustrates what I would guess is basically a single chamber pipe tuned for a power peak with a couple of muffling chambers tacked on the back:
http://www.mh-aerotools.de/airfoils/images/tpiped3.gif

On the UHP forum there's a rough diagram of a pipe with three baffles apparently inside the tuned chamber:
http://egpworld.com/forum/attach.aspx?a=1652

I gather the first baffle is the one to which the tuned length is measured, so it would be effectively the same as the first picture, just with a different shaped baffle...

What I'm wondering is, are they really flat plates with say one big hole, lots of little holes, holes of diminishing diameter? Or is that just a simplified representation of some of cone as in the first image?

I can't see how any subsequent baffles would have any effect on broadening or softening the peak if the first baffle has as small of a 'stinger' hole as suggested by that first image. If the first baffle had a 70% diameter hole, the second a 50% hole and so-on, I'd get it. But I have no idea if that is how they are... is it?

RandySmith · « **Reply #3 on:** February 24, 2006, 08:38:07 PM »

Adrian

They tune off of the first reflective surface, Which in our case is the first baffle, There are many types of configurations, one hole 2 holes 4 holes, many tiny holes.
And Yes there are 2 nd , 3rd, and sometimes 4th order waves coming from the other baffles and the rear of the pipe
We have made and tried literally 100s of differant types of baffles and pipe configurations

Regards

Randy

ash · « **Reply #4 on:** February 24, 2006, 09:28:00 PM »

Thanks for that, Randy. Sounds like I had been imagining along the correct lines. Its one of those things where I was thinking 'it can't be that simple, there must be complications...'

The complications are probably why everyone isn't making their own pipes!

phil c · « **Reply #5 on:** February 27, 2006, 05:08:21 PM »

Quote from: ash on February 24, 2006, 06:26:53 PM

I can't see how any subsequent baffles would have any effect on broadening or softening the peak if the first baffle has as small of a 'stinger' hole as suggested by that first image. If the first baffle had a 70% diameter hole, the second a 50% hole and so-on, I'd get it. But I have no idea if that is how they are... is it?

You have to remember that two things are going on in any pipe/muffler- the exhaust gas is flowing through(and cooling) and the noise in the exhaust is echoing around. The two things behave in entirely different manners, and like Randy says, it takes a ton of experimenting to see how they interact in a pipe. Standing sound waves can change the pressure at particular points, which changes how the gas flows. The size and shape of the baffles change the gas flow, which can change where the standing waves occur. The baffles reflect sound(pressure waves) but not the gas flow. Talk to an automotive muffler engineer. They have the basic auto muffler down fairly well now, but even so they spend huge amounts of time modifying and testing to get the right sound, the right back pressure, the right price, and still squeeze it into the space available.

Author Topic: Pipe Guts (Read 2113 times)

ash

Pipe Guts

phil c

Re: Pipe Guts

ash

Re: Pipe Guts

RandySmith

Re: Pipe Guts

ash

Re: Pipe Guts

phil c

Re: Pipe Guts