CBR Steering Pumps - OEM Applications?

[AgitatedPancake]

yeah that's been out for a while and somebody...honda or gm? was doing variable steering with speed with an electric setup. been a while, so details are foggy

Since the 80's from what I can tell, I'm just trying to grasp the actual physical function of the device so I'm looking for technical documentation now. Electric definitely makes sense and would be very easy to pull off. But this VAPS - is it regulating pressure or volume?

 

[Provience]

Since the 80's from what I can tell, I'm just trying to grasp the actual physical function of the device so I'm looking for technical documentation now. Electric definitely makes sense and would be very easy to pull off. But this VAPS - is it regulating pressure or volume?

Honda Global | July 2 , 1997 "Electric Power Steering System with Variable Gear Ratio Development Objectives"


it was honda that i was thinking of. electric assist with variable ratio steering rack and adjustable steering effort.


will this rack hold up to 4D's and race conditions though, that'd be sweet


edit: the Ford VAPS is regulating volume instead of pressure by regulating the orifice size from "wide open" to "full shut", but because it is still running the pump continuously, it doesn't help with the flow at idle increase or the reduced load on the steering pump

 

[SLOWPOKE693]

AW46 Hydraulic fluid.

You can get the stuff at any parts store.

 

[AgitatedPancake]

edit: the Ford VAPS is regulating volume instead of pressure by regulating the orifice size from "wide open" to "full shut", but because it is still running the pump continuously, it doesn't help with the flow at idle increase or the reduced load on the steering pump

Interesting. What I'm thinking about is the same thought as the stacked flow control valves from earlier - Reduced flow at high speed (which sounds like the actual intent of these VAPS) - Build your system with as much flow as you want at idle, and have no sacrifice of being overly sensitive at high speed. It sounds like it's a PWM controlled stepper, and depending on year it looks like they were offered with failure modes to either fail with full assist, or fail with no assist (we would want full assist with any failure of the valve for sure). But with this valve you could even probably make your steering flow digressive - get a huge amount like 6gpm at idle, but have it taper off to like 3 or whatever you want as the speed increases

Just some stuff for future reference:
Great problem solving article on a broken VAPS system with wire diagrams - https://www.justanswer.com/ford/3ea1...004-crown.html

Some guys modifying the incoming signal to change the action of the VAPS - https://www.crownvic.net/ubbthreads/...Number=1735603

AW46 Hydraulic fluid.

You can get the stuff at any parts store.

Awesome man, good note to add to the list!

 

[SLOWPOKE693]

Didn't Toyota use a power steering pump in the mid to late 90s that did the same thing described above? I remember replacing a pump and resi on my neighbors 4runner and it was some weird looking unit with an electrical connection attached to it. I thought I remember something about it being variable assist with speed. But I could be way wrong about this, it was many many years ago.

 

[AgitatedPancake]

Further thought - You can create any variables you want to control that PWM signal with a bit of computing. Maybe you want it actuating RPM dependent, or dependent on some sort of steering wheel input variable, or maybe just have a "high speed" and "low speed" modes on a toggle switch. Or anything you can think of. I'm really liking the concept behind this valve

*edit* I'm slow haha, your post showed up after I submitted mine

Didn't Toyota use a power steering pump in the mid to late 90s that did the same thing described above? I remember replacing a pump and resi on my neighbors 4runner and it was some weird looking unit with an electrical connection attached to it. I thought I remember something about it being variable assist with speed. But I could be way wrong about this, it was many many years ago.

Interesting! More to investigate

 

[Provience]

Interesting. What I'm thinking about is the same thought as the stacked flow control valves from earlier - Reduced flow at high speed (which sounds like the actual intent of these VAPS) - Build your system with as much flow as you want at idle, and have no sacrifice of being overly sensitive at high speed. It sounds like it's a PWM controlled stepper, and depending on year it looks like they were offered with failure modes to either fail with full assist, or fail with no assist (we would want full assist with any failure of the valve for sure). But with this valve you could even probably make your steering flow digressive - get a huge amount like 6gpm at idle, but have it taper off to like 3 or whatever you want as the speed increases

Just some stuff for future reference:
Great problem solving article on a broken VAPS system with wire diagrams - https://www.justanswer.com/ford/3ea1...004-crown.html

Some guys modifying the incoming signal to change the action of the VAPS - https://www.crownvic.net/ubbthreads/...Number=1735603



Awesome man, good note to add to the list!

are you still having an issue of being more sensetive at high speed (~3k rpm or??) with the smaller "stock 5.5 gpm" flow control valve in your TC pump?

2 stock TC pumps from a XJ limited to ~3gpm internally each puts out about 4.5gpm at idle and hits that 6gpm pretty quick after.

i wonder what kind of impact it would have on steering with substantially reduced flow, or rather tune the flow so it doesn't go all the way closed, at high speed in an offroad situation vs a street car situation where the tire impacts are much different.

 

[Provience]

Didn't Toyota use a power steering pump in the mid to late 90s that did the same thing described above? I remember replacing a pump and resi on my neighbors 4runner and it was some weird looking unit with an electrical connection attached to it. I thought I remember something about it being variable assist with speed. But I could be way wrong about this, it was many many years ago.

should have been the "idle up" switch for when you are at idle and lock out the steering to keep the engine from bogging down. older ones were vacuum.

but i'm going to see what the internet things of that as well

 

[SLOWPOKE693]

Further thought - You can create any variables you want to control that PWM signal with a bit of computing. Maybe you want it actuating RPM dependent, or dependent on some sort of steering wheel input variable, or maybe just have a "high speed" and "low speed" modes on a toggle switch. Or anything you can think of. I'm really liking the concept behind this valve

*edit* I'm slow haha, your post showed up after I submitted mine



Interesting! More to investigate

The drill rigs i work on use a "derating valve" for the cable crowd system to keep the mast from bending in half once you go above a certain height. When the electro valve is powered up it sends full pressure to the system. When the power is cut, it runs through a separate circuit in the valve and across an adjustable regulator that can be set to your desired pressure. I wonder if something like that could be utilized for your idea? Only problem i see adapting it to a vehicle would be the 24V coil that powers the valve. You would either have to find a 12V replacement or figure out a way to power it with 24V.

 

[AgitatedPancake]

are you still having an issue of being more sensetive at high speed (~3k rpm or??) with the smaller "stock 5.5 gpm" flow control valve in your TC pump?

2 stock TC pumps from a XJ limited to ~3gpm internally each puts out about 4.5gpm at idle and hits that 6gpm pretty quick after.

i wonder what kind of impact it would have on steering with substantially reduced flow, or rather tune the flow so it doesn't go all the way closed, at high speed in an offroad situation vs a street car situation where the tire impacts are much different.

Right now it honestly feels great at speed with the .64ci pump and 4.5" pulley. But I'm still 3.5 seconds lock to lock at idle due how much volume my system has, so I'm still planning to step up to one of the .80ci pumps (very possibly going with Radial Dynamic's). If I bump up my flow valve orofice diameter to match well with what that pump can do at my engine RPM, I'll be increasing sensitivity on the freeway probably more than desireable.

In the worst case i could step down to a smaller ram diameter, but I'd prefer not to if possible haha. I should be able to get sub-3 second lock to lock with a step up in pump size though.

 

[Provience]

Right now it honestly feels great at speed with the .64ci pump and 4.5" pulley. But I'm still 3.5 seconds lock to lock at idle due how much volume my system has, so I'm still planning to step up to one of the .80ci pumps (very possibly going with Radial Dynamic's). If I bump up my flow valve orofice diameter to match well with what that pump can do at my engine RPM, I'll be increasing sensitivity on the freeway probably more than desireable.

In the worst case i could step down to a smaller ram diameter, but I'd prefer not to if possible haha. I should be able to get sub-3 second lock to lock with a step up in pump size though.

"bump up my flow valve to match that pump"...that's where you are losing me

pump flow should be matched to your steering servo and volume. if your happy 2000 engine RPM time of 2.5 seconds is good and is also about 4.5 GPM, then you should be able to get radial to send it to you with the flow control set to cut out about there instead of at 6 gpm.

figuring his CBX is 0.80 with porting for higher flow, you are at 20% more volume than what you've got.

sticking with your 4.5" pulley, the CBX would put you at just over 4 gpm at idle for your ~2.75 second time and you could easily limit at 5gpm just about 1k engine rpm for 2.5s without much issue.

i wonder if using a larger displacement pump would give a more stable control through the orifice or more variation


you NEED more displacement to get your idle flow regardless, you MIGHT want an extra layer of flow control. might as well try the pump and see how you like it at speed before dropping some money on an extra valve

 

[AgitatedPancake]

bump up my flow valve to match that pump"...that's where you are losing me

As of my current thought process, I like the idea of the flow valve cutting in not too far after idle. Right now my calc is showing me my current 5/32" orofice flow valve should be somewhere around 3.75 gpm, and happens somewhere around 900 engine RPM. If I just slap a larger displacement pump on with my current orofice diameter, it'll be bypassing below my idle RPM, and would hardly be helping my steering speed at idle. So I'd have to increase the orofice diameter with the higher displacement pump to make sure it cuts in at a higher GPM, and ensure it's a higher RPM than idle.

The calc tells me I probably want a 4.25-4.5 gpm cutoff with my current theory. But if these factory flow controls are around 90% efficient (which doesn't seem too far off so far), 5k engine RPMs will still be creeping up past 6.5 GPM. Not that I'm planning to run the engine that high for any period of time, but the extra volume I want down low, is leading back towards that overly sensitive high speed experience that I've already encountered. So if I can get that gpm at idle, but then choose to decrease flow at higher road speeds (maybe even below that 4 I have available at idle), that's just about all I could ask for.

 

[Provience]

As of my current thought process, I like the idea of the flow valve cutting in not too far after idle. Right now my calc is showing me my current 5/32" orofice flow valve should be somewhere around 3.75 gpm, and happens somewhere around 900 engine RPM. If I just slap a larger displacement pump on with my current orofice diameter, it'll be bypassing below my idle RPM, and would hardly be helping my steering speed at idle. So I'd have to increase the orofice diameter with the higher displacement pump to make sure it cuts in at a higher GPM, and ensure it's a higher RPM than idle.

The calc tells me I probably want a 4.25-4.5 gpm cutoff with my current theory. But if these factory flow controls are around 90% efficient (which doesn't seem too far off so far), 5k engine RPMs will still be creeping up past 6.5 GPM. Not that I'm planning to run the engine that high for any period of time, but the extra volume I want down low, is leading back towards that overly sensitive high speed experience that I've already encountered. So if I can get that gpm at idle, but then choose to decrease flow at higher road speeds (maybe even below that 4 I have available at idle), that's just about all I could ask for.

yeah but that was closer to 8 or 9 gpm that you were having sensetive issues. I'm fully with you on the speed sensitivity concern, that is one of the big drivers for why i want to use a load sense flow and steering valves. less regard for pump output and more regard for servo demand. also because it seems any auxillary valve is going to be 150-250$, it would be worth it to try without one first simply because i'm a cheapass


have this dude setup your pump to the 4.5gpm cutoff and then make a video of it at your various RPM's to see what it is actually flowing and staying in that range. it would save a bunch of guesswork on your end for hole diameter and fine tuning it, because that is going to be darn near Test, remove and file slightly larger, install and test, remove and file, etc. until you are happy with it. but then there is no going back if you overdo it

 

[AgitatedPancake]

yeah but that was closer to 8 or 9 gpm that you were having sensetive issues. I'm fully with you on the speed sensitivity concern, that is one of the big drivers for why i want to use a load sense flow and steering valves. less regard for pump output and more regard for servo demand. also because it seems any auxillary valve is going to be 150-250$, it would be worth it to try without one first simply because i'm a cheapass


have this dude setup your pump to the 4.5gpm cutoff and then make a video of it at your various RPM's to see what it is actually flowing and staying in that range. it would save a bunch of guesswork on your end for hole diameter and fine tuning it, because that is going to be darn near Test, remove and file slightly larger, install and test, remove and file, etc. until you are happy with it. but then there is no going back if you overdo it

He's definitely first on the list once I'm tired of experimenting. But I may have a cheap reman CB pump with the bigger ring sitting on the bench that I want to blow up first haha. I'm probably going to put a 4.5" pulley on it, and melt the bushing out of it from overdriving it too much, then cave and get his badass pump with roller bearing support haha.

 

[Provience]

He's definitely first on the list once I'm tired of experimenting. But I may have a cheap reman CB pump with the bigger ring sitting on the bench that I want to blow up first haha. I'm probably going to put a 4.5" pulley on it, and melt the bushing out of it from overdriving it too much, then cave and get his badass pump with roller bearing support haha.

twerk your cheap CB and it will probably outlast your current rig

my daily driver is nearly 30 years old and the stock pump started making noise. all i could think was "damn, this thing really has a leak?" uh yeah, 30 years and 300k miles later....

 

[Provience]

so the question then begs, do you risk trying out 3/16" diameter orifice that should put you about 4.3gpm at 50 psi pressure drop or shoot for 11/64" first?

#15 drill is 0.180 and right in between

 

[AgitatedPancake]

Hahaha right. I know they're pretty durable, but I may end up spinning it pretty fast for that poor bushing so we'll see!

so the question then begs, do you risk trying out 3/16" diameter orifice that should put you about 4.3gpm at 50 psi pressure drop or shoot for 11/64" first?

#15 drill is 0.180 and right in between

So I was thinking 11/64" would probably be my first increment, but discovered a catch. the CB flow control valve itself is slightly longer, which means it has higher spring pressure when resting against the fitting(spring length and other domensions seem to match the TC). That means it requires more pressure drop to open the same amount as the TC. And the flow return orofice back into the pump body for recirdulation is a larger size. Does that mean the same diameter orofice will have different results than the TC? Probably, damnit lol.

Edit for a link, here's one of the only articles that almost puts numbers on things. They mention that each of their different orofice diameters go up in .007 increments, and the full sweep goes from 4-12 liters per minute. But they don't tell you what each individual option flows unfortunately

http://mooregoodink.com/in-all-proba...eering-feel-2/

 

[Provience]

Hahaha right. I know they're pretty durable, but I may end up spinning it pretty fast for that poor bushing so we'll see!



So I was thinking 11/64" would probably be my first increment, but discovered a catch. the CB flow control valve itself is slightly longer, which means it has higher spring pressure when resting against the fitting(spring length and other domensions seem to match the TC). That means it requires more pressure drop to open the same amount as the TC. And the flow return orofice back into the pump body for recirdulation is a larger size. Does that mean the same diameter orofice will have different results than the TC? Probably, damnit lol.

Edit for a link, here's one of the only articles that almost puts numbers on things. They mention that each of their different orofice diameters go up in .007 increments, and the full sweep goes from 4-12 liters per minute. But they don't tell you what each individual option flows unfortunately

http://mooregoodink.com/in-all-proba...eering-feel-2/

so they go from 1gpm to 3gpm with 9 valves. 1 and 9 are the bookends, so we are getting 0.25 gallons per minute per orifice number and they are using 0.007" diameter increase per size.

each 64th of an inch is just under 0.016", so about 2mm and about 0.5 gpm according to them, it obviously not linear, but meh, close enough

if you are running 5/32 and netting about 3.75 GPM, then they must be calling something like a #29 0.136" drill (ream) for their 3gpm #9 big valve. If we use that math, then to go from 3.75 gpm cutoff to 4.5 gpm cutoff, we'd need to reach 0.177" with is a #16 drill (ream) and just shy behind my midpoint guess of a #15 0.180

so yeah, try out 11/64" and pick up a reamer set if you don't have one. if you aren't in a hurry, i'm pretty sure i have a # set of reamers if you don't and i'll try not to fuck up a simple hole for ya.

 

[Provience]

“Although several of our competitors have tried over the past 16 years to duplicate this process,” adds Roper, “it cannot be duplicated in mass-produced OEM pumps—that’s the difference between a $200 production pump and a $600 proper racing unit. Wide tolerances cause excessive internal leakage that makes it impossible to regulate the output flow of the OEM-style pump.”

this is also what radial dynamics ran into early on dealing with some stuff, not sure if he said it in this thread or not, but trying to outsource and find quality and reliable pump bases to work off of is important. i'd say moreso for a manufacture/dealer and less so for an individual in a shop because we can use junkyard stuff and modify one thing to do one thing the way one person wants it. Will it cross over exactly for anyhbody else with anyother junkyard pump? Not likely. hence the earlier "file, test, file, test" joke

 

[AgitatedPancake]

The one catch about jumping straight up to the 11/64" in the CB is the impact from the additional spring preload via the longer valve, so I may have to start small to start over. Man I wish I had a flow meter haha. I definitely hear where you're coming from with the inconsistency across pumps as well. I may find a dialed in solution for mine, but that may not be able to directly cross reference to other people.

TC flow valve is the short one, CB is the longer one. But they seem to use the same springs

 

[Provience]

valve length and spring preload being related to a higher pressure relief setting should have more of an impact on force rather than flow volume. with a higher psi relief setting, let's say you were at 1100 psi before and going to 1300 psi, you are going to have less input force required on your steering wheel. it should be 'easier to steer' but it should be any faster or slower for the net steering speed.

if removing washer makes for higher relief PSI, then adding a washer (shim) should lower it. might be worth it to pull apart the valve, measure whatever the shim thickness that is there currently and double it. that would give you lower PSI and higher steering wheel input force required. "more road feel"

edit: 11/64 should leave you enough room to do a final ream to #16 if you still need more.

 

[AgitatedPancake]

valve length and spring preload being related to a higher pressure relief setting should have more of an impact on force rather than flow volume. with a higher psi relief setting, let's say you were at 1100 psi before and going to 1300 psi, you are going to have less input force required on your steering wheel. it should be 'easier to steer' but it should be any faster or slower for the net steering speed.

if removing washer makes for higher relief PSI, then adding a washer (shim) should lower it. might be worth it to pull apart the valve, measure whatever the shim thickness that is there currently and double it. that would give you lower PSI and higher steering wheel input force required. "more road feel"

edit: 11/64 should leave you enough room to do a final ream to #16 if you still need more.

PSI is all related to the internals of the pictured valves (which I haven't analyzed yet in the CB), but the primary big spring these valves rest against sets the amount of static preload the flow valve has against the output fitting, and dictates the amount of pressure drop necessary for the flow valve to shift rearward in the bore and bypass fluid. So the fact that this valve assembly is longer, means the flow control spring is compressed more at rest meaning more force. So the flow valve has more force to overcome, meaning more pressure differential necessary between the front face and rear face of the valve

 

[Provience]

PSI is all related to the internals of the pictured valves (which I haven't analyzed yet in the CB), but the primary big spring these valves rest against sets the amount of static preload the flow valve has against the output fitting, and dictates the amount of pressure drop necessary for the flow valve to shift rearward in the bore and bypass fluid. So the fact that this valve assembly is longer, means the flow control spring is compressed more at rest meaning more force. So the flow valve has more force to overcome, meaning more pressure differential necessary between the front face and rear face of the valve

or it means the bores and ports are physically different between the TC and CB pump.

as an example, looking at the orifice chart from pg 2 for 5/32", 44 psi for 3 gals, 123 psi for 5 gals, 490 psi for 10 gals, the required PSI drop increases significantly for more flow. if we are figuring about 50psi gives about 3.75 gals from about 5/32 drilled, it requires a pretty significant increase in pressure drop to increase flow from the same hole. even if the CB pump is ultimately capable of handling ~150 psi total load higher (radial offer 1800 psi CB while Trailgear offers 1650 psi TC) do we really think the OEM is building a much more significant amount of bypass pressure? that would mean the pump case itself would be seeing 200+ more psi before failure. maybe, but i'm not sure it is going to be a significant enough psi drop to matter.

especially when 11/64 is theoretically still small for what you are looking for cutoff flow.

I'm not sure, but i'm along for the ride and appreciate you taking the time to document all this


edit: regarding internal differences, if you put the same main spring behind each valve and on the table and measure the free height vs the preload height, then you should be able to add shims until you get the same preload on both valves and get the CB valve to match the TC relief pressure close enough

 

[HYDRODYNAMIC]

Man I wish I had a flow meter haha.

Get a 5 gal bucket with marks every 1/2 gallon to fill and a 5 gal bucket of cheap hydraulic oil to test with. Run it for 30 seconds and do the math. Bypass the reservoir lines straight to the buckets.

 

[AgitatedPancake]

Shoutout to my buddy that took a set of pin gauges to a stock fitting for the sake of tech, .133" orofice diameter in stock form.

 

[MtnYota]

Just to add orifice size data:
PSC sells flow control valves for TC/CBR pumps have a -6 outlet with a 0.160" orifice
https://www.pscmotorsports.com/replacement-parts/psc-sf25.html

-8 outlet has a 0.180"
https://www.pscmotorsports.com/replacement-parts/psc-sf29.html

They also list p pump flow control valves with the same size orifice for -6 but the -8 is slightly smaller at 0.170"

 

[MtnYota]

I have a CBR pump from a 2017 Duramax on my Explorer. The steering is slower than with my PSC TC pump on my Toyota. Based upon this thread I was expecting to have a small orifice that needed to be drilled out. I pulled my flow control valve to find that the orifice was huge 0.241, the (4) cross drilled holes were 0.105" and the tiny hole above the threads was 0.051, but the spool valve below it had a plunger like an internal bypass in a shock.

​
See the piece inside the needle nose pliers. I'm assuming it has and OD of 0.170. This reduces the area inside the orifice to a net area equivalent to 0.160 or almost the same as what PSC lists.

Anyone ever dealt with a spool valve like this?

 

[AgitatedPancake]

Thanks for adding in the orofice size data! We talk about drilling to 11/64", which ends up being .172 just to compare to those references.

Your second image isn't showing up, but that's a very interesting concept you're describing so I hope you can reshare it. I'm interested to hear more on this CBR pump. I ended up purchasing a CB pump from one of the vehicles Radial mentioned early in this thread, and can confirm every crucial dimension of the vane pump is larger than its TC counterparts which confirms the additional displacement volume, but I haven't tested it on the jeep yet. Actually I'm still decently content with the 4.5" pulley on the TC for the moment, but still plan to run the CB with the same 4.5" pulley just to bring that lock to lock time down further

 

[MtnYota]

Let me know if the pics are working now

 

[AgitatedPancake]

Yep it's working now, that's a very strange looking spool valve. I've seen the shorter valves with more ribbed sections like that, but none with any sort of extension that goes up inside the fitting orofice. Is that silver piece in the pliers pressed/screwed into the body of the spool valve? I wonder why it's a different material. Interesting all around, and I'll be curious if the others know more