I just got my P5 mounted up with dual 444c’s and a 5 gal tank. Running 175psi, i think thats a little much, so I am going to run lower psi to lower the pitch/keep the horns alive longer.
Question, What is the best balance between sound and loudness psi wise?
Also, i am using 1/2" line with an elbow at the tank and horns themselves. Is this enough air flow? The horns seem to take about .5 sec to sound fully after the solenoid opens.
horns 1,2,3 dual diaphragm
horns 4,5 single diaphragm
They say you shouldn’t run more than 150 through the horns and ideally they go very nicely at just over 100 as well. This is relative in my opinion because you have to keep in mind - car mounted horns generally have a fairly small supply of air. If you drive a train then your air supply is virtually limitless.
I run 5 gallon with my K3 @200 without regulating the pressure down. The amount of time the horns get exposed to 200 is a joke really. You open the taps and it would take less 2 seconds or so to get below the 150 mark.
Sure the horns will probably stress out a little more getting that initial burst of high pressure air, but if you’ve ever had one apart you know how darn sturdy they are. If I was blowing them heaps every day, I’d probably consider a regulator, but other than that I’m not in the least bit worried.
The other point I should make is that regulating your pressure down will somewhat extend the small amount of air you have in your tank - that to me is a far better reason to install a regulator and I’ve been eyeing one off purely on that basis.
I would keep 200 in the tank, and 120 or so at the outlet going through the Graham White, but I’d also keep the other line through the solenoid at 200 to ensure I have maximum impact when I need to mash the horn button.
Your solenoid is most likely to far from the horns (learned from experience)
The P3s and P5s have A very small feed orifice in each bell. Also make sure you have the solenoid as close to the inlet of the horns as possible.My P5s are A little slow also. I did all the above and they are never as instant as my K5s but do sound good. It is not recommended to run high pressure with the P3-P5s as you will have shorter diaphragm life. and yes more pressure makes mine louder but causes A squeal before honking. Like the gentleman above me said 150 max PSI. Just my two cents been there done that Rex…
P horns are great because you can get more honking time. I use 150 psi to a 5gal tank, regulated down to 110 out to the horns. Just as loud, easier on the diaphragms.
If you ask a collector at Horn and Whistle, they will say no more than 120 and no less than 90
For me, I run 100 through my tuned K5 because thats not only what the guy who tuned it recommends, but its the happy medium for loudness and quality of the chord produced. It also makes your air last a bit longer if you have it regulated down from a higher psi.
More pressure does not lead to a better sounding horn for sure. I started out looking for “LOUD” but sure learned a lot from the horn and whistle board. Less is more much of the time.
High pressure is more likely to distort the sound too.