dealtileman....that's surprising that 35 hrs bogs that much . Have you asked SS about it? There may be heat exchange backpressure robbing a little HP
I can run 2k and 45 with 31 no problem
my hot shot machine only has 18 hrs and can run 36 and 2500 psi no problem
at 4gpm, gas engine requirements between 1200 and 2000 is around additional 3 HP
the 2500s does not bog down but you can tell that it is working very hard and at near its operational higher specifications is all.
with machine at full rpm at pump set to 2000 psi and you block off the vac port to simulate full hg load the machine will not bog down at all just works harder without skipping a beat, just sounds and feels like the engine is working at the top end of its range.
general pump at 2000 psi at 5.6 gpm will require a bit greater than (gas) 10.5hp alone.
the gardner denver at 14" hg pulling 350 cfm at 4000 rpm will need in excess of (gas) 17hp.
the belt cooler, i can imagine needs a 2 hp (maybe less couldn't find specs)
water pump 11hp
blower 17hp
belt cooler 2 hp
total hp 30 hp
so of the available 35 hp my unit is using 30 hp to run wide open at its operating limits. running and using almost 86% of total power available to run at top of specs. i would love that number to always be under 80 percent but it is close.
this is not a secret and
sapphire knows this and this is why they have multiple machines in their lineup to choose from. you pick the machine best suited for your needs and for the scenarios you will be cleaning the most.
the 2500s is more for tile and grout, concrete and other hard surfaces where you might need 2500 psi for a particular type of hard surface job.
sapphire uses the same pump on multiple machines but restricts (by warnings) the psi to 1500 psi to ensure hp to stays in range of specifications of engine.
most people should not even use 1500 psi as this is a very high operating pressure, that WILL cause damage if you don't know what you are doing, i am just listing specs and top ends the machines were design for.