I have upgraded the pump to a saginaw with just over 100Bar and a 4mm hole in the straining section in the output fitting.

I see most people have success with 1,75" cylinders. However here in Sweden I can only easily chose between 40mm and 50mm cylinders. This corresponds to 1,57" or 1,97".

As I understand it I get a twitchy steering with too much flow and too small cylinder. Do I risk getting too slow response with the 1,97" cylinder?

Both give me a 75% ratio of area on the return stroke to the out stroke, so no difference there.


Opinions?

Tobias

I would go with the smaller diameter. You can always restrict the flow. You'll get less assist, but your steering will be less "twitchy"

with a P pump you won't need much assist anyway, unless you're running very wide tires in the rocks.

depends if your haulin or crawlin. If you only drive at low speed in rocks, you will prefer the bigger bore. if its an all around truck, go with the smaller bore. I ran a 2 inch bore with a toyota box and it was slow as hell, it only made a difference on the road though.

OK I gave too little information to work with.

It's a RRC with volvo portals running TSL /SX 38,5-14.5-15.
Strictly trailer queen for the foreseeable future. Getting it road legal is a dream that will probably only turn true if it is required to be able to wheel where I want to wheel. Roadworthiness, beyond getting legal is not an issue, it will never (again) be a runabout.

Not strictly rocks, but nose down in a tight situation is not enough with P-pump 100Bar and stock rover steering box.


I think I have some videos at home where it is apparent what is happening.

Tobias

A video showing just the kind of situation i tend to find myself in, where I definitely would like a bit of power in the steering is at
http://tobias.eller.nu/filmer/SDC11999.mov

I had just very nearly flopped to the ridht as the right front wheel came off a ledge I did not see.
My spotters were duly ignored as I "knew better" :evil:

Bigblue:
so the box influences the cylinder bore, I've so far only seen references to the pump.

I will never drive fast, only the inspector doing the manouverability tests to get it legal will ever be stupid enough to do that with this contraption, if I ever get to that stage. But for the inspection I may just remove the cylinder and plug the ports :flipoff2:

T

The flow through through the box influences the shaft speed greatly! Some steering boxes have better flow than others. A smaller bore gives faster response time with less force, a larger bore gives more force with a slower response time. I didn’t find a great deal more turning force with the ram-assist. What I do know is that by mounting the ram on the opposite knuckle of the draglink you greatly reduce the forces on the steering linkages and box. Less bent links and broken sector shafts make it worth the while. By the way, does any one here know how to port a Rover box for ram-assist?