Boost controlled washer pump (don't laugh it's a real problem)
 

Ok, this is going to sound funny at first, but here is the issue. I have a supercharged 944 running about 12-psi boost. So I am installing the ERL H2O injection system to help with in cylinder cooling even beyond the aftermarket intercooler I have. So I have mounted a 5-gallon collapsible water jug in the rear cargo pocket, run a water line to the engine compartment to the pump. Now the way the ERL system works is that under boost a pressure switch is activated and supplies a certain amount of resistance to the pump to turn it on. My problem is that the water tank sits lower then the pump in the engine compartment so I need a secondary pump to get the water to the injection pump. So ERL recommends a washer pump, cheap item. But they also recommend that’s it's boost activated! How in the world will I pull this off! I am one step away from selling this whole project for a 951!

Scott,

VDO makes a pressure operated switch. It has NO & NC contacts, & its switching pressure is adjustable. Don,t have the part number or know how many amps the switch is good for (may also need a relay). You can check VDO's web site and contact technical service.

drew1

Well, you could wire in a relay so the current that's supplied to the first motor just powers up two relays, one for the original motor, the other for the washer pump you've got...

OR you could install a check valve after the motor to make sure it never runs dry...
Ahmet

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It has a one way check valve at the pump inlet side, and then also has a one way 1 bar check valve where it's tapped into the blower to prevent the vacum syphoning the water into the blower at idle. I can't figure out what would be so bad about having the primer pump run all the time?

Never mind solved my problem. I am going to sump washer fluid into the H2O system. Turns out it contains 20% methanol which is recommended for my system Should burn great in the combustion chamber.

Just redirect your washer lines from the hood nozzles to the intake. Anytime you want boost, just hold down the window washer switch. The only side-effect will be that the windshield wipers will run while on boost. You can probably use them as a sort of boost gauge. When the wipers are going, it is either raining or you're on boost.

Dave