Pressure Regulator--Downstream or Upstream

I’m loving the K3’s–I have them tucked up under my Mazda Miata. Running a 4 gallon tank (where the spare tire used to be) at 150psi. Air Zenith compressor can handle 200psi, and so can the tank. So running the horns at 130 to 150psi through a regulator would give me a bit more horn time between recharges.

So here’s my question: if I use a pressure regulator, I know going downstream of the solenoid valve is suitable, however, given how tight things are in the Miata trunk, it would be easier to put the regulator downstream of the valve. Any thoughts? If the regulator were downstream of the valve, would the impulse on the regulator damage it?

The regulator I have to use is one from McMasterCarr… says 225SCFM max (I think that’s right). It has 1/2" inlet and outlet.

Would appreciate any experience, comments and/or thoughts!

It might cause some damage, and if thats a concern then I would put the regulator either directly off the tank or right before you get to the valve.


Sweet, a Miata with a K3.

I’d put it between the tank & solenoid valve. That is not a scientific answer though.

Anybody observe a notable reduction in horn sound quality and/or volume when using the McMasterCar pressure regulator?

I thought I saw on the forum somewhere the amount of air a K3 consumes in CFM