[nick_bj40]

Firstly I am planning to run a stock vitara power steering box and pump but the ocd side of me wants to know more about an upgrade but don't want to jump into the upgrade without some information from people that have done it already.

As the title states I have noticed trail gear have a power steering pump rated at 1400psi 4gpm compared to the stock vitara 800-1300psi 1gpm and before under taking the conversation would this hig flow pump make a noticeable difference from the stock pump?

[rick1970]

1st off...I have NFI what the output of a std Vitara pump is....but 1gpm sounds low....somewhere around 800-1300psi sounds about right, but would guess on the lower end..

If this is right...your input HP required automatically goes up 4 fold....heat generation goes up and with no other mods to control it...will probably end up bad in the long term. Constant high heat is not nice to seals and hoses. I personally wouldn't consider a change to a larger pump without at least looking at the cooling, be it an oil cooler or a larger reservoir. Line sizing may also have to be considered.

The pressure gives you the effort to turn the wheels, not the flow. And if you don't actually need the extra pressure to turn, it will only be reached when you get to full lock. I guess with enough tyre, a slight increase in pressure could be worthwhile.

The flow governs the speed at which you can turn the wheels. If you can't turn the steering wheel fast enough to outrun the std pump, all the extra flow will do is generate extra heat. Add a assist cylinder and its a different story. Adding the extra swept volume to the steering circuit pretty much demands more flow from the pump, but not necessilary more pressure

About the only time an actually bigger pump flow with a std system may be worthwhile, is operating at idle, and if the actual pump flow is lower than the control orifice output sizing, and you really need to turn the wheels fast...

Bear in mind these are a positive displacement pump, spin it twice as fast and you get twice the flow. The control valve/orifice at the outlet port of the pump will control this to its setting, but the pump element inside will still continue to pump more oil as you spin it faster....you just don't get it all from the outlet port. A general rule is, the bigger the pump displacement, the lower its maximum operating speed is.

To give you an idea, and I can't remember the exact specs of the top of my head, you average US based truck runs about 6-8gpm at 1800-2200psi...with a bloody big steering box, lots of tyre and a more weight over the steer axle than you Suzuki would ever weigh.

[got_bar_work]

I have the lowrange pump and a 12in. heat sink cooler
need to put the idel up switch inline as its still hard to turn down that low .just need that few more rpm then its fine
its a lot of work to setup as u need to get custom lines made

[pezz]

i would be asking for some more detailed spec's
i.e.
flow and pressure at 800rpm, 1200rpm, 1600rpm, 2200rpm ect ect
or better still a bench test sheet of its full range

then i would do the same test on the vit pump myself

[Ratty562]

I run a vit pump and a jimny box turning 35s and it seems to turn them fine with no problems

[nick_bj40]

Firstly thanks for your replies and what all of you are saying is what I was thinking/wanting even with my vague description

On the cooler side I agree without a cooler or at the very least a larger res it would be no chance it would work. after only a few turns the heat would surpass the system limits which is why I would definitely run both a tube and fin cooler (mainly due to already having one) and run a 1litre minimum res

Does the 12in cooler keep the temperature under control? would an idle up switch be easy to setup?

I would like the specific specifications for the pump but I think I would be to lazy to bench test the vitara power steering pump due to lack of time to do it properly but would it really tell me that much about the existing pump or is it mainly for low rpm comparison?

I know it's been covered before but how different are the vit and Jimmy boxes? I Would imagine that the vit box would be larger than the Jimmy if it is the vit pump be an upgrade from the stock Jimmy pump??? Or have I got it all wrong...

[got_bar_work]

It looks like the pressure switch on my j20 pump should just unscrew and i will just make a inline fitting for it
i didn't run one on the old 1.6

[pezz]

i run a jimny box and jinmy pump, yet to hook up the idle up solenoid, but i mostly drive with my parkers on so it is active anyway
i run a 1ltr res, even when crawling it doesnt get hot, but im only on 30's