The video shows pulses of 10psi or more the spikes also give you a higher reading then what you would get snubbed. If you speedometer or boost gauge did that would you consider it accurate?
The reason you have a snubber is not to break pressure guages do to pulse spikes. They are designed for just these types of pumps.
Secondly the more voltage you add the higher the psi, so when people state
300psi possible its not what your going to get on your vehicle eletrical system.
Number one the pump head is not rated for that nor are the seals or diapharm just because you can does not mean you should, The is pretty much no reason to run that kind of pressure and stress your pump and shorten it's life. You mate up the proper nozzle size with a dynamic range to cover your needs.
Mine is bigger than yours is not always the right way of thinking.
Anyone can achieve those psi if your run the pump at a higher voltage than what a normal auto produces. The pumps can run safely up to 18volts.
We keep it close to specs as possible to make the system last longer. Plus true numbers help the person tunning know how much they are actually spraying per nozzle size. No leaving them thinking I got a M5 it's spraying at 150psi so I get X amount of flow at x amount of volts. If your getting 300psi on a M5 hate to see what happens when you switch to a M3 nozzle and to the internals of the pump after a few months.
Anyways here what we put out with our new pump,
Since today is a federal holiday (10:50 am Guam time for me) I went ahead and tested all the nozzle out. Probably in the middle of the night there for you guys in the states.
Test conducted with a snubbed 3" Glycerin-Filled Gauge with NIST Certificate. Keeps things nice and smooth with no guessing on .exact numbers.
12-30VDC Power supply at a concerevitive 13.25 volts. All numbers rounded down to the nearest multiple of 5.
Most important thing to remember, nozzle size determines output pressure.
M1 (not tested)
M12 (not tested) did not have one handy.
So these are are numbers pump pushes plenty hard but not at a level that is to far above the pumps internals specs for pressure. Longevity and proper nozzle sizing is key not how much pressure you can squeeze out of the pump.
We use a different cam in our pump and it keeps things at a level we feel gives you more than enough flow but not to much stress on the pump. If you contact shurflo they will highly, highly recommend you never run 300psi with these pumps. Especially continued use.
Its always better to run a larger nozzle instead of a smaller nozzle at a higher psi with the same output.
This is post is only to show what kind of numbers these pumps put out, at least ours.