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Steering Displacement and Speed Calculator

The discussion on electric is pretty interesting. at 12V I do see that 400 amp draw, but in reality that concerns me less that it seems to concern a few of you. That's not what the system would be drawing in any sort of regular situation, just at max output volume with maximum PSI resistance in the system. So in reality you'd only spike the system pressure pretty intermittantly. Just like the PS pump, it's not requiring that kind of horsepower until the situation calls for it. You may want to put a bigger alternator on sure, but I think the electrical system could be made to keep up with relatively common components. The struggle of the sheer size of a pump that can handle the volume and pressure requirements we have would be the biggest hurdle though, not sure how to get around that one.

I also have another update for the calculator, I edited the first post with it as well.

-Added a pump efficiency variable so you can account for real world losses
-Labeled the axes of the chart
-Rearranged a few cells, added some appreciation to Radial Dynamics for your input!

https://alpinepeakprecision.com/tech...0-%20V1.2.xlsx

Power%20Steering%20Displacement%20-%20V1.2.jpg - Click image for larger version Name: Power%20Steering%20Displacement%20-%20V1.2.jpg Views: 0 Size: 255.3 KB ID: 263639
 
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400amp @12v may not be concerning, but there is also the added efficiency loss from all the excess plus the not-insignificant wear and tear on the batteries. also, go spec out a 200+ amp alternator. running dual alternators solves some of that issue, but then again is adding more complexity for little real gain.
 
Provience said:
400amp @12v may not be concerning, but there is also the added efficiency loss from all the excess plus the not-insignificant wear and tear on the batteries. also, go spec out a 200+ amp alternator. running dual alternators solves some of that issue, but then again is adding more complexity for little real gain.
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Agreed there is efficiency loss, I'd be curious to see the actual efficiency of alternators, vs vane style hydraulic pumps, vs gear style hydraulic pumps etc. 200+ amp alternators are expensive, but you can find 160 amp or greater factory bolt on options from some more modern vehicles, so you can come across those pretty conveniently. The big benefit to electric in my eyes is having 100% system capacity at idle, and linear feel across the spectrum with no wasted energy in the upper RPMS
 
also, you will hit max PSI everytime you turn the wheel to full lock, just something to keep in mind. which, in crawling at least, happens pretty often even if the rest of the typical steering load doesn't require much force
 
Provience said:
also, you will hit max PSI everytime you turn the wheel to full lock, just something to keep in mind. which, in crawling at least, happens pretty often even if the rest of the typical steering load doesn't require much force
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Just by nature I bump full lock and immediately back off to shut the hydraulics and get out of bypass, but I do realize that may not be the norm so it would really be a case by case basis
 
I guess I don't really see the gain and do see a bunch of extra weight and a few more pieces for efficiency loss, compared to running engine driven pump and using valves to regulate flow. if you can't get what you are after, a second PS pump weighs as much or less than a second alt and certainly less than an electric motor to drive it and an extra battery, boom, instant doubling of your idle output :rasta:
 
Provience said:
I guess I don't really see the gain and do see a bunch of extra weight and a few more pieces for efficiency loss, compared to running engine driven pump and using valves to regulate flow. if you can't get what you are after, a second PS pump weighs as much or less than a second alt and certainly less than an electric motor to drive it and an extra battery, boom, instant doubling of your idle output :rasta:
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Ohh for sure, I'm just playing devils advocate to thoroughly compare both options. It would have the efficiency lost through other items, but if it's a power on demand system (which I'm not sure if they are), it gains tons of efficiency and frees horsepower in the higher RPMs of an engine while hydraulic pumps are pumping 10-20gpm and recirculating most of it (even though it's low pressure, but if it has a couple hundred PSi loss, that's a few horsepower lost). Granted it shouldn't be building too much pressure if restriction is low so it shouldn't be robbing too much horsepower, but that would be a +1 for electric. Weight is definitely a downside, no disagreement about that at all. Just an interesting back and forth overall, but I do agree that engine driven hydraulics are the way to go right now
 
AgitatedPancake said:
Agreed there is efficiency loss, I'd be curious to see the actual efficiency of alternators, vs vane style hydraulic pumps, vs gear style hydraulic pumps etc. 200+ amp alternators are expensive, but you can find 160 amp or greater factory bolt on options from some more modern vehicles, so you can come across those pretty conveniently. The big benefit to electric in my eyes is having 100% system capacity at idle, and linear feel across the spectrum with no wasted energy in the upper RPMS
Click to expand...

Just a thought...maybe pull a page from the car stereo world and run a capacitor of some sort to help smooth out the demand spikes on the system?
 
Interesting subject as I will have to change all the front accessories on my SBC. When I built it, Steering demands were not what they are today. A "normal" pump and a V belts would do the job. Now, for my system, it is the TT pump, with 6+wide pulley's. The number of fans also increase the alternator load. I just happened across a couple 375 amp alternators for a "deal" so now I have some choices. I still believe wide pulley's will be needed, but options to hide the PS pump and motor might be in the cards. (A KOH car regularly takes about 220 amps to run on a consistent basis. Apparently the $$$ digital motors help that situation)
 
A capacitor may actually be a nice addition to provide that surge discharge and smooth out the draw seen by the upstream components, interesting thought.

Isdtbower said:
Interesting subject as I will have to change all the front accessories on my SBC. When I built it, Steering demands were not what they are today. A "normal" pump and a V belts would do the job. Now, for my system, it is the TT pump, with 6+wide pulley's. The number of fans also increase the alternator load. I just happened across a couple 375 amp alternators for a "deal" so now I have some choices. I still believe wide pulley's will be needed, but options to hide the PS pump and motor might be in the cards. (A KOH car regularly takes about 220 amps to run on a consistent basis. Apparently the $$$ digital motors help that situation)
Click to expand...

Are you considering the electric route, or just thinking about how to configure a TT pump alongside high amp alternators?

Not that I'm convinced of electric necessarily yet, but this has been an interesting thought exercise. I stumbled across some interesting pumps, unfortunately at 2.5 GPM they don't have quite enough GPM for what we want, but dual units paired up, and you could configure them to run in full parallel with check valves (offering redundancy), or have them activate sequentially. at 25lbs ea, I'm honestly surprised they aren't heavier. The only big thing I haven't found yet is duty cycle, as I assume these aren't 100% but don't actually know. 5gpm at idle with up to 3k psi on tap sounds pretty slick.

https://www.grainger.com/product/36NE10
 
AgitatedPancake said:
A capacitor may actually be a nice addition to provide that surge discharge and smooth out the draw seen by the upstream components, interesting thought.



Are you considering the electric route, or just thinking about how to configure a TT pump alongside high amp alternators?

Not that I'm convinced of electric necessarily yet, but this has been an interesting thought exercise. I stumbled across some interesting pumps, unfortunately at 2.5 GPM they don't have quite enough GPM for what we want, but dual units paired up, and you could configure them to run in full parallel with check valves (offering redundancy), or have them activate sequentially. at 25lbs ea, I'm honestly surprised they aren't heavier. The only big thing I haven't found yet is duty cycle, as I assume these aren't 100% but don't actually know. 5gpm at idle with up to 3k psi on tap sounds pretty slick.

https://www.grainger.com/product/36NE10
Click to expand...

should be around 3-10% loaded duty cycle
 
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