Hello, I have a quick question regarding the PSI on the power steering. I did a search and found the normal operating PSI on our vehicles is 80 - 125psi. I would like to know if there is a way to lower that. I would like to use a P/S pump for an oil pump to a remote/rear mounted turbo. Will using a heavier weight oil reduce the psi? or using bigger lines? too much pressure is not welcomed. Also, what size are the fittings on the back.... lastly, would a smaller P/S pump off a smaller vehicle have smaller psi? say, a pump from a Cavalier or something? Thanks in advance...

 

The 80 - 125 psi is during a normal no assist time. Once you start turning the steering wheel the P/S pressure can go as high as 1200 psi.

The pressure is controlled by the flow control valve that is threaded inot the back of the pump. These are interchanable over a number of year (all the way back to 1st gens). They are available with make & female 45* inverted flare along with o-ring type Saginaw fittings.

RBob.

 

sounds doable. The way it will be connected is Power steering pump to turbo in the back then back to steering pump. I would only need about 30-50psi and maybe less. Would this settup keep the psi constant when the pump is operating at different rpms? Since there would be no "assist time"? So I would just need to find the proper fittings and the correct flow control valve? Thanks again

 

I don't know about the psi, but I'm pretty sure power steering pumps only push fluid. With a rear mount turbo it's more important to get oil from the turbo to the front, not the front to the turbo.

 

wouldn't the pump push the oil to the turbo and keep pushing until it got back to the pump? If all the lines were solid and did not expand?

 

Won't work. Any back pressure on the turbo drain and the oil goes out the seals.

Also, the oil exiting the turbo is a froth. Need a pump at the back to move the oil back to the engine. The feed to the turbo can come off of an oil passage port on the engine.

RBob.

 

I was looking at different PS pumps and saw the early 90's Honda had an external reservoir, what if I connect the turbo feed into a pressure passage on the engine, and the oil return to the ps pump and then the PS pump to the engine?

 

The return line on a PS pump isn't designed to suck fluid, and I highly doubt a PS pump could make any kind of beneficial vaccum that wouldn't also damage the pump if it could even make any vaccum at all.

The oil pump for the motor is fine to create the pressure to drive fluid to the turbo. You need a pump that can either suck oil from the turbo or a pump mounted as close as possible to the turbo that can push oil back to the front of the car.

 

yeah, thats what I was afraid of. I guess I'll have to with an electric pump...

 

The pump pushes high pressure to the steering box. Low pressure is returned. The power steering pump is also used on the GM hydraboost brake system. Same thing happens.

Technically it could work for a turbo oil system as the oil that comes off the turbo bearings will be at low pressure. The downside is that the turbo is really heating up that oil more than the pump does. It doesn't have much of a reservoir to dissipate that heat and I doubt a power steering oil cooler would be enough even at that distance.

It would probably be easier to just plumb it into the engine's oil system as per normal.

 

yeah, thats what I was afraid of. I was hoping to use the pump in an enclosed "circuit" so it would be sucking all the time with no reservoir...