My original horn kit came with nylon tubing, maybe 1/4" but not sure. I didn’t use it because it was fairly rigid and more difficult to route around bends, corners, through side panels and frame holes, etc. I ended up buying some very heavy, thick, high-quality Goodyear rubber air hose as shown below:
The hose is much more flexible with a larger interior diameter than the nylon tubing - looks to be 3/8" or 1/2" ID but I never measured it. It uses 1/4" NPT fittings so I connected everything with high quality automotive-type quick disconnect fittings. I have used it for almost 2 years now and never had any leaks or problems. It holds up well to the elements and doesn’t crack, split, or warp.
So I am wondering is a rubber air hose better, worse, or the same as nylon tubing? I just upgraded my single small compressor to dual Viair 400C units and a 7-gallon tank. I am willing to upgrade the hose or switch to tubing if there is a benefit.
Another thought is that you lose a little output PSI with bends in your line due to turbulence in the air stream. Being somewhat rigid keeps the run rather straight and any curves slow instead of sharp. It would never make a huge difference, but just a tidbit to add.
This rubber air hose is pretty thick, maybe 1" O.D. or a bit larger, and it is reinforced with some kind of nylon braid in the outside layers. It came as one single 25’ length but I just cut it to size with a razor blade and added my own connectors using barbed NPT fittings and hose clamps. This has worked really well without any air loss.
Total length of hose in my setup is about 4’ from the tank to a 7-port aluminum manifold and then another 4’ from the manifold to the solenoid which is mounted directly to the horn. Very few bends and none of them sharp, no kinks in the hose. Even when I bend the hose at 90-degrees it still does not collapse the inside diameter - the exterior is thick and strong enough to keep the airway open. I am sure every line will lose some PSI due to line resistance but this is probably less than 1-5 PSI, if that.
I am waiting on my new Air Zenith digital gauge, the new model which is on backorder. I could hook the sensor for it on the pressurized side of the solenoid to measure PSI at the horn but I suspect it will be the same throughout the line until you open the line and air starts to flow. My main concern about my air hose was diameter. Is 3/8" or 1/4" inside diameter enough for the Shocker XL or should I step up to 1/2" inside diameter or larger?
I was worried about this but my entire setup is installed inside the truck bed which is enclosed by a hard cover, and the portion of the hose which runs under the truck actually runs inside the C-channel frame rail so the hose is not directly exposed to any elements. This hose is rated for exposure to gas, oil, and other solvents so maybe it holds up better than other similar air hoses. It is about 2 years old now with exposure to hot southern summers and cold northern winters with no signs of rot. Hope it stays that way but if any leaks develop then I will probably go to nylon.
That’s pretty key. One of the most important features of the nylon tubing we sell is its UV resistance. From what I understand ozone and UV are the largest contributors to ‘dry rot’ in rubber.
The Shocker horns operate fine with a minimum feed line of 6mm ID (just under 1/4in ID: 15/64in). So either 1/4in or 3/8in will work. With the XL kit we recommend 3/8in ID since it matches the valve and will make the horns significantly louder.
There is a 77% increase in the capacity of the line when comparing a 3/8" ID round air hose to a 1/2" ID round air hose. That is a HUGE difference but you may not actually see that big of an improvement. It depends on the number and size of your fittings, length and type of hoses, air tank capacity and psi, valve flow rate, horn consumption rate, and any leaks which may exist in your system. I am currently using a top quality 3/8" ID rubber air hose and 1/4" NPT fittings so the flow is constricted somewhat by the fittings but it still works great with my Shocker XL and Omega AH-500 horns. I eventually hope to upgrade to 1/2" ID hose and 1/2" NPT fittings but I haven’t been able to find all the fittings and manifolds at a reasonable price and I am not sure it will be worth the effort given how good my current setup sounds. I would be curious to see if anyone on this forum is using 1/2" ID line and 1/2" NPT fittings throughout, and if so then did they see any big peformance jump?
I used to have 3/8 dot line and my horns just didn’t sound right. So on the Doc’s recommendation, I went to 5/8 DOT line witch has an I.D. of .450 Vs the 3/8 .250. I also bought A High flow valve as the one I had was to restrictive for the Nathans.Now I run lower pressure to my horns and the they sound great.It has been my experience that to much pressure made my K5 setup sound (squeaky) so I turned the pressure down via A regulator to 140 and like it there.
Everyone has their own preference…
