triggering an electric power steering pump.

[sheepers]

ive got an MR2 electric P/S pump for the crown and im wondering how best to trigger it on and off.

from what im told the MR2 has a pressure sensor in the rack that triggers the pump as soon as you turn the wheel. my steering box has none of this trickery so im going to need to do it another way.

how have you seen it done? there are a few ways but if you know of a good way let me know.

thanks!!!

sheepers.

[flyingbrick]

Fuckin phone... Il try again.

Pretty sure the mr2s steering assistance is dependant on vehicle speed and I think there are also sensors to tell the car when the steering wheel is being moved.

You should def fit some kind of pump speed controller so that you can vary steering assistance from in the cab! And have it vary assistance based on vehicle speed too

Ned could prob design you a thing to do it in 5 seconds

[ta63-1uzze]

Yes they have a module that has uses an optical sensor input from the steering shaft (cabin side) this tells the ecu the steering angle ,also it uses a speed sensor of the gearbox so that at high speed you don’t have full power to the pump as it makes the steering to light. The pump has 3 possibly 4 power inputs ( i can’t remember as it’s been so long since i have played with one)

you could just wire the pump to mid speed, so the pump is always on , key on power, this is not a problem and it is how most hot rod / stock car / modifiers run there pumps. If you have an output from the gearbox or even from an aftermarket ecu then you could potentially use the factory mr2 steering control module, just need to fit up the angle sensor

I used one of these pumps on my old car it works well as a single speed pump.

[ProZac]

Going the same route with my black Starion. Going to use a solid state relay, and setup a little box that feeds the relay a PWM signal, the duty cycle of which decreases with increasing speed (to decrease the assistance at higher speeds). Not sure what sort of frequency to drive the signal at, but that shouldn't be too hard to figure out.

As an aside, doing the same thing with solid state relays, and your fuel pumps (but an increasing duty cycle instead of decreasing) is a great way to make them nice and quiet at idle .

[sentra]

@sheepers did you end up using an electric pump and figuring out how to control it? my boat uses a power steering pump for hydraulics for lowering/raising the jet unit reversing cup thing, i am considering replacing it with an electric mr2 unit due to availability issues of the current (broken) one thats driven off the timing gears.

[sheepers]

yes.

its not very scientific, its either on or off and it runs off a battery charge circuit from a campervan.

because the car has some heavy current loads (compressor etc) i wanted to have it switch off if there wasn't enough current to go around.

thats it, nothing fancy at all.