Train Horn Writeup Part 1 of 2: Components


Posted on: June 19th, 2011 by Child of the Sunfish

This is a write-up for my train horn, which I installed into my BF mk II XR6. It consists of 2 bells, a quad tone train horn and a dual tone truck horn and is operated via a momentary pushbutton switch, which is mounted just below the steering wheel. This is to keep the factory horn in tact and avoid unecessary trouble from the man.

I thought it would be cool to install a train horn into my car, as I did with my old car, only with a few upgrades this time. I still had all of the components from last time however I needed new tubing and I wanted to install all of the wiring properly. In the picture below you can see the original truck horn that I had installed in my AU Fairmont. There are 3 components to this project; the air tank, air compressor and of course the air horn itself, or bell.

 

I couldn’t find any technical data for the bell so I am unable to say how loud it was, but I estimate it to be 80-90dB. I learnt a few good tricks and lessons from installing it last time, like what direction the bell should face, how to secure the components properly etc… so I was keen to do a professional job again this time round.

I had to source some supplies first, as I had to wreck some shit to remove the horn last time, because I was in a hurry. Firstly, I needed some 1/4″ nylon tubing. This is the airline from the tank to the bell. I got what I needed from www.hoseonline.com.au, who are Victoria based which meant quick shipping times. The exact product can be found here. 10m and shipping set me back about $25AU.

Secondly, I wanted to upgrade the bell to something a bit louder. A company called Air Ride helped out here. They have all of their products on their website and they also have an eBay store, however as they are located in Bayswater I just went to their shop. They were good blokes. After doing a lot of research, I bought a Kleinn quad train horn, which has the following specs:

Specifications
Construction Chrome plated zinc alloy
Overall Length (in.) 14.5
Overall Width (in.) 7
Overall Height (in.) 7
Max Input (psi) 160
Output (db) @ 100 psi 149.2
Output (db) @ 150 psi 150.3
Solenoid 307 Vortex 4 12v DC
Shipping Weight 5.5 lbs

The product page can be found on the Kleinn website or some more information/pictures can be found on the Air Ride website. The main feature of the horn was that it is 150dB loud, whereas my previous horn was ~90dB. I’m pretty sure that 150dB would rupture ear drums, so I highly doubt that it’s actually that loud. There is an extra 2 bells as well, which means more frequency range. This bell, coupled with my existing dual tone truck horn should make some nice noise.

So the idea is that the air tank will provide the required air pressure of 145psi to the horn, however I will need some way of keeping the air tank filled up. One option, as I did back in the day, is to put a tyre valve on the air tank and use the tyre inflators at service stations, or use my air compressor at home to manually fill it up. It’ll work, but the horn typically gets around 10 seconds of blast time before the tank needs filling again, so this isn’t really practical.


Enter the air compressor. Forged in the fires of hell and powered by the souls of children, this beast makes Hitler look like a kindergarden teacher. It almost weighs as much as my car. It’s a diff-lock compressor, and was a present from my uncle who used it to power his airbag suspension on his truck. His truck! Typically diff-lock compressors are used to modify how the diff operates in 4WD off-road conditions, so they have to be pretty powerful. I’ve done a few tests with this thing and while I’m not sure what the max psi level of air this thing could push through, it drew the same current and made the same noises at 130psi as it did at 0psi, meaning it wasn’t even breaking a sweat. There are 4 ports on this weapon of mass destruction that can be used, which means besides running a line to the air tank, it’s possible to install an air tool valve for a flexible hose for mobile tyre inflation, or an air gauge or whatever else you can think of.


The only thing required for this compressor was to upgrade the pressure switch, as shown below. The guys at Air Ride gave me a switch that will turn off the compressor at 145psi, and on again at 110. Previously it operated at 120/100psi. This was $25. As my uncle, who is a mechanic is shutting up shop soon, I went to his workplace to pilfer whatever fittings I could, and walked away with quite a loot, which will come in handy for running the two air horns using a T-piece, which is not shown.

So the next step is to get all these bits mounted safely in the car, connect the air lines and wire everything up. See part 2 for mounting the components (when I write it), and wiring it all up.