The pump says its rated for 12v so I am running it a bit faster than it should. Maybe that contributes to the louder noise? The pump has a built in pressure switch that is adjustable with a screw on the top. https://www.amazon.com/dp/B087BZLJJ2?psc=1&ref=ppx_yo2ov_dt_b_product_details
I did have an idea to put in a buck converter to step down voltage, but I guess I was more interested in having a solid way to mount it first since the electrics would be easy. Thanks for the suggestion, back to the workshop!