Outer Limits 4x4 Board

What are the specs for the ram for doing this?

Beebee what ram did you use and how much was it?

Howdy guts i had some made some time ago 1 3/4 bore 1/2 rod so as to max force in both directions and has about 200mm stroke. I was going to put twin cylinders but just cant find the room now only fitting 1. Done the calc's and at full p/steer pressure ( ~1500 psi ) gives 1600kg of force. Im only using 1 so am prepared to part with the second. PM if interested

Wally

Guts wrote:What are the specs for the ram for doing this?

Beebee what ram did you use and how much was it?

hey guts,

the best cylinder for the application would be a ag cylinder,

PTE make a good but cheap cylinder, and come in all diff strokes makin it more versitile,

here's a link showing all sizes, the best one would be the 2" bore 1" rod
http://members.westnet.com.au/ptehyd/slm.html
the size that 80ute suggested seems that the rod is to small, it wont last as long. Rod buckling is more likely to occur, also having alot bigger bore compared to rod size, u will get side load on the piston cause of the flex in the rod which will end up milling the barrel of the cylinder.
here's the link to the home page of PTE
http://www.ptehydraulics.com.au/
also here is a chart explaining rod buckling
http://members.westnet.com.au/ptehyd/slmload.html


the info u will need guts is,

full extension,
full retraction,
and stroke can be worked out from them.
also u could use stop tubes to limit either extension or retraction,

if ya need any more info just let me know.

Chad,

Talk too me and i'll take you too a place were they are cheap.

If the cylinder is to large the metering valve in the steering box will not allow sufficient flow and when steering fast the steering will be heavy untill the flow catches up. I have kept the cylinder small and the rod small to minimise the differential effective piston area's so it is effective in both dirrections. The load on the cylinder is with in operating specs of that size rod and if the rod is to large the assistance turning one way can be significant different compared to steering in the opposite direction. It is paramount the the cylinder body is free from binding to so it stay aligned between either rod ends. The rams i had made were made to opperate in the horizontal position as they are fitted with long piston so wide wear strips could be fitted and the gland has a long bush on the oil side of the seal ensuring good lube and good support of both the piston and the rod.

Wally

Now I`m getting confussed (not that it takes much) Which setup is going to be better.

I need 2 rams, one for the hilux and one for the GQ diff in my buggy.
For the hilux I`d want one that has good power but it would have to be quick as it is street driven and will be doing some winch challenges. The one for the GQ diff would need to be powerfull as it will be used in big rocks etc, but it will also have to beable to keep up with the steering speed.

80utes ram sounds like the go for speed steering and 1600kg is a shite load of extra force.

I used to use a 2"bore with 3/4" shaft. I did experience some lag when trying to turn at speed. It was fine with general street driving but I used to notice it most in carparks

beebee wrote:I used to use a 2"bore with 3/4" shaft. I did experience some lag when trying to turn at speed. It was fine with general street driving but I used to notice it most in carparks

did y drill the orifice out in the pump to give u more flow?.


80ute, that was good thinkin about giving it a longer piston and gland, most people wouldn't even think of the possibility of side load, but i still think the rod diameter is to small,

guts if i was u i'd go with the 2" bore 1" rod, drill the oriffice out in the pump to allow more flow and you should be right, don't bump ya relief pressure up though, your pump wont handle it.

good luck with it guts,

customhilux wrote:

beebee wrote:I used to use a 2"bore with 3/4" shaft. I did experience some lag when trying to turn at speed. It was fine with general street driving but I used to notice it most in carparks

did y drill the orifice out in the pump to give u more flow?.


80ute, that was good thinkin about giving it a longer piston and gland, most people wouldn't even think of the possibility of side load, but i still think the rod diameter is to small,

guts if i was u i'd go with the 2" bore 1" rod, drill the oriffice out in the pump to allow more flow and you should be right, don't bump ya relief pressure up though, your pump wont handle it.

good luck with it guts,

How do you get more flow from the pump by drilling the oriface, the pump is a fixed displaplacement balanced vane pump and the only way to get more flow is to spin it faster . To get more flow at the same revs you need a bigger pump and the metering valve in the box can only handle x amount of flow. The steering in a winch challange/endurance/rally 4B still needs to have relativley fast steering so its a comprimise on how much force compared to speed. I need more assistance when manouvering with low tyre pressures outerwise the std p/steering is fine and by keeping the cylinder small it should have least impact on steering speed and sufficient assitance to steering force and not to much that can overload tie rod ends

wally

80UTE wrote:The steering in a winch challange/endurance/rally 4B still needs to have relativley fast steering so its a comprimise on how much force compared to speed. I need more assistance when manouvering with low tyre pressures outerwise the std p/steering is fine and by keeping the cylinder small it should have least impact on steering speed and sufficient assitance to steering force and not to much that can overload tie rod ends

wally

This is what I want exactly for the ram on the hilux. For the GQ diffs on the buggy I still need speed but also need alot more force.

80UTE wrote:

customhilux wrote:

beebee wrote:I used to use a 2"bore with 3/4" shaft. I did experience some lag when trying to turn at speed. It was fine with general street driving but I used to notice it most in carparks

did y drill the orifice out in the pump to give u more flow?.


80ute, that was good thinkin about giving it a longer piston and gland, most people wouldn't even think of the possibility of side load, but i still think the rod diameter is to small,

guts if i was u i'd go with the 2" bore 1" rod, drill the oriffice out in the pump to allow more flow and you should be right, don't bump ya relief pressure up though, your pump wont handle it.

good luck with it guts,

How do you get more flow from the pump by drilling the oriface, the pump is a fixed displaplacement balanced vane pump and the only way to get more flow is to spin it faster . To get more flow at the same revs you need a bigger pump and the metering valve in the box can only handle x amount of flow. The steering in a winch challange/endurance/rally 4B still needs to have relativley fast steering so its a comprimise on how much force compared to speed. I need more assistance when manouvering with low tyre pressures outerwise the std p/steering is fine and by keeping the cylinder small it should have least impact on steering speed and sufficient assitance to steering force and not to much that can overload tie rod ends

wally

don't know the pumps on a car, but found it on marlin crawler
http://board.marlincrawler.com/index.php?topic=10579.0

might help ya.

Dave try and source the hydro assist set up off the old statesman's , Brougham or chevy's

beebee wrote:I used to use a 2"bore with 3/4" shaft. I did experience some lag when trying to turn at speed. It was fine with general street driving but I used to notice it most in carparks

Having driven daves car with the hydro
i must say i cant belive how bad it was just so slow
it slows the whole operation down, so so slow

but Really good off road

Drilling out the relief valve does nothing to assist flow....until you drill it out 0.5mm too far and then the pump starts to cavitate. Once this happens, you get heaps of flow but you can't sustain a cavitating power steer system. This leads me to believing that the flow restriction comes from the steering box as once cavitation begins (and air enters the fluid) speed jumps right up.

beebee wrote:Drilling out the relief valve does nothing to assist flow....until you drill it out 0.5mm too far and then the pump starts to cavitate. Once this happens, you get heaps of flow but you can't sustain a cavitating power steer system. This leads me to believing that the flow restriction comes from the steering box as once cavitation begins (and air enters the fluid) speed jumps right up.

y don't u run a bigger tank then, cavitation has to be coming from your suction line.

I would have thought the 4L tank that I run would have been enough

beebee wrote:I would have thought the 4L tank that I run would have been enough

it might not be cavatation but airation.

It's all due to drilling out the relief port. I've tried 3 times now (with 22R pumps) to step up the hole size in 0.5mm increments. There is no noticable difference until you go that one step too far. Speed is then unbelieveable but the pump will have a very short life.

sounds like every one has the same problems.


I run the double ended ram of Glenn's and when i first connected it up to the 80 series box i found that it was powerful but slow.

to try and fix the prob i sped the pump up (by putting a smaller pully on it)
drilled the hole. and upped the spring pressure on the valve in the pump.

I think the most of the problems are in the steering box not the pump, you are tring to force more than twice the amount of fuel through the box than what was intended.

my steering is ok now but every now and then i get the cavitation problem.
I have a few more ideas that im going to try i will post what i find.

i know all this limits the life of the pump but without a full pump change out this is all i could come up with and it work for now. just got to remember that it wont go lock to lock a fast.

Chad (the bathurst Chad )