I built my own relief valve for that very reason of water psi. I couldn't find any other solution beside a garden hose gate valve which I thought was crazy. My inlet and outlets are 1/2" NTP and just after the reduced pressure side, I installed a "T" fitting where I ran a gauge 0-30 psi. and even with a 1/2" pipe I still coudln't dump enough water at WOT. It gets as high as 25 +/-psi. What side are the inlets/outlets on your valve? I don't have headers so I have no idea about enough pressure to open your header feed valve, but I think they are around 10psi when they open. I would recommend installing a sea strainer before the valve cause I sucked up some debris a few times and it was a bitch trying to fix it out on the lake.

On my boat I say no. I want people paying attention and hanging on. You never know when you have to make a quick turn to squirt some river ants.  Your all ready driving a hotrod boat full of near naked women "hopefully " you dont need unwanted attention from the popo.

Good point. I guess if I can't drink, they can't.... well, unless we're stopped checkin out the view

Anyone know of any way to I.D. a boat for sale by using the CF or HIN? Example; CF numbers not matching the Hull/ registration. I looked a boat and the reg. papers show a different CF # but the HIN is correct. Anyone ever heard of that? Kinda fishy....