21" Grover Air Horn with 6" Flare
Running off a 10 gallon air tank at 120 psi. Operated by an electric solenoid air valve with a switch run to the dash.
It's obnoxiously loud. At some point, I'll try and get my hands on a camera that can take video to give a real demo of it, but in the meantime, here are some lovely pics.
Unfortunately the easiest and essentially only place it would fit is where I put it, on the right rear frame rail. It worked out nicely as I ran my air line through the floor of the trunk and right to it.
Yes it's a tad bit ghetto, but hey, it works.
Yeah it's not super shiny or anything, but it wasn't in tip top shape when I bought it on ebay, total cost of the project ran about $120, and it puts those cheap red plastic air horn kits to shame. This is full on big rig loud.