I’ve been searching the internet for a few days now looking for information on a whistle that attaches to a vehicles exhaust and sounds like a train. OK, I heard a lot of groans. Please forgive my intrusion on this site. I want to make one, can’t afford to buy one. I’ve actually been working on some and now realize it may be a lot more shall I say detailed than I first thought. I can get a tone out of the ones I’ve made and realize the length of pipe is critical. I need to know the other critical dimensions and design criteria. For instance should the air source be at an angle to the pipe, or parallel to the pipe. How far from the fipple? The ones I’ve made tend to go shrill when I increase the air pressure. Any help, would be appreciated.
I think you’ll need three separate whistles, because train whistles play chords- major in the US and minor in Canada. Will it sound constantly, or will you pull a cord?
I plan on using four to play a chord? Have an on off hook-up designed already. I need help with dimensions for whistles.
Cyfiawnder sneaks out of his Lurking Cave…
Why not use the compressor from a Turck Airhorn (available at most autoparts stores). You could hook it up to a seperate Switch and therefore you would only get the “toot” when you need it. Besides inserting a Fipple into your exhuast flow would restrict the gasses so badly that you would loose all power, and eventualy turn your valves into carbonized piecies of dog dookie 
Ever drive a car with a clogged catalytic converter?? It would be worse than that… The tone that would get the most reponse from people would be a Major “power” chord like from a Guitar, A three string Chord involving two notes exactly an octave appart, and a “4th” like C4,G4,C5
Cyfiawnder sneaks back into his lurking cave…
It could cause back pressure and damage to your engine, or worse carbon monoxide in the car. In some states you might get a ticket for altering your exaust system. And there are some chiff & Filpplers that frown on whistleing and driving. But if you get it to work, let me know how to make one. Maybe it would work on a lawn mower.
I think I’ve got those problems worked out. I’ll install on a '29 Model A. The exhaust will have a valve that I can control the amount of gases going thru the whistle, never the entire exhaust flow. Because of the slow speed you can idle the old car it gives a distinct cadence to the whistle. What I need is help with the shape and design of the whistle. I don’t know what the important dimensions and angles are. Thanks.
Have you looked at one of these?
That’s what I love about this board - where else but at C&F could you learn this? I asked several learned muscian friends this question and stumped them all.
Craig, I have one of those sitting next to 'puter. My dad used to carve them. In fact have half a dozen around here.
If anyone is interested in more train whistle trivia here you go. Robert Swanson, another British Columbian whistle maker, invented the whistle that most North American trains use. He was a poet, logger, story collector, air brake inventor and government forestry safety inspector who died in 1994. His train whistles were called Airchimes and they can be heard, along with others here:
These websites might help a bit, but I sort of doubt it:
http://www.geocities.com/SoHo/Lofts/6611/makewhis.htm#tuning
http://www.dougsparling.com/irishmusic/whistle/whistlemake/
http://jubileeinstruments.messianic-webhosting.com/experiem.htm
The last one seems to have things that talk about the ratio of the length to the bore, etc.
David and Cynth, thanks for the links. Some of these sights are loaded with info. Nothing I like more than learning something new. I spent about four hours yesterday working on this. Have a solid support for pipes, made a diffuser to send exhaust to each pipe, have one pipe that has a pure sweet sound. Now have to figure out why that one sounds so good and apply that to the others. Thanks again.
Well, good luck. I hope to hear you if you ever drive through Iowa.
Panpipe Theory
Tubes must be 1/4th the frequency wavelength, tube diameters must be between 1/7th and 1/14th of the tube length and the thickness at the voicing must be 1/8th" or greater or the tube will have difficulty resonating.
You can search the diagrams at this site for closed tube designs that can be adapted to your project…
Click on the “illustrations” section (left frame) after you enter the site. Here is an example…