Electric Power Steering

[patooyee]

After installing an electric power steering unit from a Saturn Vue on my Rzr and being super pleased with it, I started thinking about how nice it would be on a buggy. No power steering pump, no hoses, no heat, no noise, lots of assist when needed, little assist when not needed, fairly robust, works without the engine running, etc. I figured that, surely a larger unit would be needed and then I read where it is now an option on F-350's. (It's what allows the automatic trailer backing feature where you just let go of the wheel and hold a button and the truck parks the trailer for you.) The Saturn Vue system isn't really that complicated. I wonder how complex the Ford system is? Anyone know anything about it?

 

[WoodburyZuk]

This may not apply to you, but I have heard that on rigs with armstrong steering it can put a lot of stress on the sector shaft because it is not designed to have that much power going through it.

(Only speaking about a stock samurai manual box)

that being said, I would still give it a try. Samurai boxes are a dime a dozen and I probably have 5 kicking around. Had I not already done a toy box and a Jeep pump I would have probably gone with the Saturn vue route myself.

 

[TrailTamer]

I brought this up at the old place and got shot down, because its "stupid".

I am with you, EPAS seem to be a huge gap waiting to be filled in in the 4x4 world.

My idea I had was to use EPAS with regular PS steering system, instead of hydro-assist, for similar reasons as you listed, possibly make for a set-up thats simple and works.

 

[woods]

This was going to be the setup I used on the Samurai if I had gone with rear steer.

 

[HYDRODYNAMIC]

The F150 ES rack is 125 amps x 14V = 1750W = 2.34HP
TC at 4GPM at 1800PSI = 4.2HP
CBR at 6GPM at 1800PSI = 6.3HP

Not enough HP for large tires off road

 

[Provience]

i doubt you'd hit the speed and strength of hydro, but if you aren't trying to shift the rig with the tire against a rock while crawling it'd probably have good feel.

it'd probably outperform a stock pump hydro setup while at idle

 

[Etyler2]

A friend of ours is going to try it on his next buggy from a Volvo. Fire pit talk so that’s all I got.

 

[patooyee]

The F150 ES rack is 125 amps x 14V = 1750W = 2.34HP
TC at 4GPM at 1800PSI = 4.2HP
CBR at 6GPM at 1800PSI = 6.3HP

Not enough HP for large tires off road

I wonder what the f-350 unit is though? The new F-350 is rated for SOOOOO much more weight than an F-150. Its actually kind of amazing what their spec'ing at these days.

 

[Provience]

also, since you brought it up, post up some pictures and details on the setup you are running on your SXS patooyee

 

[patooyee]

also, since you brought it up, post up some pictures and details on the setup you are running on your SXS patooyee

It's nothing new. This is where I learned of it:



Mine didn't come with ps from the factory so it was a complete installation for me. I wasn't replacing a defective unit.

 

[Provience]

yeah i know they've been done before on several different things, most of them lightweight stuff it seems. just curious about the pictures and such. thanks for the link

 

[patooyee]

yeah i know they've been done before on several different things, most of them lightweight stuff it seems. just curious about the pictures and such. thanks for the link

It was a pretty easy install. It's hard for me to work at my shop right now for several reasons so I did this at home with a grinder and a $150 Everlast 110 Tig welder.

 

[rattle_snake]

Some are using Prius EPS on old fords to add power assist. Install unit between Colum and factory non/pwr steering box. No need to change shitty linkage. For grandpas in their otherwise stock truck the prius EPS unit is enough.

 

[patooyee]

The F150 ES rack is 125 amps x 14V = 1750W = 2.34HP
TC at 4GPM at 1800PSI = 4.2HP
CBR at 6GPM at 1800PSI = 6.3HP

Not enough HP for large tires off road

Another thing ... EPS normally isn't the only source of mechanical advantage in the system. There's normally a rack or manual steering box after it. I don't know how that factors into the equation.

 

[patooyee]

yeah i know they've been done before on several different things, most of them lightweight stuff it seems. just curious about the pictures and such. thanks for the link

Here's a video of with and without. I have 30" tires on my XP 900. I think stock size is 26".

Google Photos

photos.google.com

I benefitted from EPS being an option on my model. So I just found the OEM bracket on eBay for $17 shipped and it pretty much all bolted up exactly like the instructions stated. The kit comes with two extra weld-on joints that you basically splice into the stock steering shaft to make two shafts out of. The kit was designed for newer model Rzr's than mine so the shaft lengths were different from the instructions. The upper shaft was a lot shorter than they said it would be. The joint yokes are basically welded directly to each other with only a 4mm spacer between them, but it works.

The kit comes with a small potentiometer and knob that you install in the dash to manually adjust assist level on the fly. The Vue motor is about double the power of other aftermarket kits and more than double the Polaris factory motor that comes on Rzr's with the option.

 

[ManKrawler]

Watching as I have a Epowersteering kit on two RZR's running 35's and on slickrock they get hot and shut off. Ken at EPS.com just admits we are beyond the limits of the Saturn Vue unit. I even run an air filter on the dash with a bilge pump fan through 3d printed manifolds to cool the unit with a large heat sink attached to it all.

We are considering driving TC pumps off the stator side of the crank and going full hydro.

I researched every standalone PS unit I could during da covid without finding anything that created enough GPM at a reasonable amperage for a RZR. I already struggle maintaining a high enough voltage and amperage through the dual output stator, aftermarket regulators, and dual odyssey batteries as it is. A 100+ amp alternator in a buggy is another story. I will try and go find a couple of the trick stand alone solutions I found, there is even steer by wire units coming out for the commercial industry.

There is also the noise of the pump to consider:

 

[patooyee]

Watching as I have a Epowersteering kit on two RZR's running 35's and on slickrock they get hot and shut off. Ken at EPS.com just admits we are beyond the limits of the Saturn Vue unit. I even run an air filter on the dash with a bilge pump fan through 3d printed manifolds to cool the unit with a large heat sink attached to it all.

We are considering driving TC pumps off the stator side of the crank and going full hydro.

I researched every standalone PS unit I could during da covid without finding anything that created enough GPM at a reasonable amperage for a RZR. I already struggle maintaining a high enough voltage and amperage through the dual output stator, aftermarket regulators, and dual odyssey batteries as it is. A 100+ amp alternator in a buggy is another story. I will try and go find a couple of the trick stand alone solutions I found, there is even steer by wire units coming out for the commercial industry.

There is also the noise of the pump to consider:

Have you considered just using a bigger unit? The Vue unit is 500 watts. The f150 is over 3x that at 1750. I bet there's units out there between those as well.

What setup is that video running?

 

[arse_sidewards]

For an off road application I think that having the additional power input upstream of the gear reduction is a recipe for broke parts unless you can over-spec a rack. That's easy enough to do in a SxS or Zuk but anything bigger and there aren't many good options.

Ford uses a traditional power steering system in the F350 with the fancy active steering. I presume they just use an EPS actuator to turn the wheel. In any case they are not relying on the EPS to provide the bulk of the force to turn the tires.

There really are no good manual steering gears or racks that can take rock crawling abuse. So you're back to needing some sort of assist system that directly acts on the knuckles or tie rods in order to keep that force off the gear/rack. That in mind, I would just do a manual full hydro system. Instead of a power assisted column you use a simple motor. This is the kind of system you find in many boats. If you are planning on adding EPS to give you more force than spec the motor on the column on the larger side in terms of displacement.

 

[DMG]

The F150 ES rack is 125 amps x 14V = 1750W = 2.34HP
TC at 4GPM at 1800PSI = 4.2HP
CBR at 6GPM at 1800PSI = 6.3HP

Not enough HP for large tires off road

Is electric and hydro power steering really a 1:1 comparison? Look at how power is delivered in an electric car vs a gas motor and auto Transmission

 

[ThePanzerFuhrer]

Did you look at a smart car rack? It’s electric power steering also.

 

[HYDRODYNAMIC]

There are column mounted EPS and rack mounted EPS. The F150 uses a rack mounted motor.
The column mounted is the easiest to adapt for assist in front of an existing gear or rack.

Data below was sourced from Ranger Station
EPS from Toyota, Nissan and Kia/Hyundai works in fail-safe. The ECU for the column is mounted remotely and can be disconnected and removed. The EPS from Saturn Vue and Chevy Cobalt has an ECU that cannot be disconnected. They have no fail-safe and a 3rd party eBay control module is needed in order for it to work stand alone.

Below is the list of cars that are known to have fail-safe electric steering. Only (3) wire connections; Ignition On, Power, and Ground to the Steering ECU.

ECU Part Numbers:

2004-2009 Toyota Prius 89650-47102
2009-2013 Toyota Corolla 89650-02300
2006-2011 Toyota Yaris – (With ABS) 89650-52120 / 52050
2007-2009 Nissan Versa 28500-EM30A / 991-30303
2009-2012 Nissan Cube 28500-1FC0B / JL501-000932
2012-2014 Kia Soul B2563-99500 / 4PSG1312 / FPSG1312

Looks like the KIA SOUL is one of the larger units.

F150 Rack

Diagram is a Jeep JL power steering pump 125A

Gladiator electric power steering delete kit

 

[HYDRODYNAMIC]

Previous non electro hydraulic Jeeps-
Relief pressure is 1450 psi ±50. At 1500 rpm the flow should be 2.29-2.68 GPM.

I assume that the electro hydraulic system is going to be near the same output given that the vehicle specs are nearly the same and both use a gear box.
125A at 14V = 1750W same as the F150 = 2.34HP
1500PSI x 2.5GPM /1714 = 2.18HP

I am guessing that two of the electro hydraulic pumps could be run in parallel to double the output to get into an acceptable range.
You would probably need a high output or a second alternator to keep up with the power use in the rocks and low rpm charging high steering use situations.
Not that I need to derail my steering system. But I would not be afraid to run dual or triple Jeep electro hydraulic pumps in place of an engine mounted CBR. I would probably upsize the cylinder from 2.5 to 2.75 -3.0 to get a little more force.
A flip of the switch or limit switch on the shifter could enable the number of pumps on at one time to have selective output for less sensitivity at speed and more power at low speed in the rocks.
If PSC is selling a number of these kits then a number of E pumps should be available.
The E pump looks to have a simple reservoir design for remote mounting and connecting multiples together.

 

[YotaAtieToo]

As mentioned, once they get hot, you're kinda screwed. I wasn't happy at all with mine on my honda sxs. I feel like it's much easier to add cooling to a hydro system than an electric.

 

[arse_sidewards]

As mentioned, once they get hot, you're kinda screwed. I wasn't happy at all with mine on my honda sxs. I feel like it's much easier to add cooling to a hydro system than an electric.

Obviously less is better but does anyone know what an acceptable sustained temperature for these things is assuming you want a similar to OEM lifespan.

Steering rack can live in a pretty hot place on a lot of vehicles. Obciously under the dash column mounted stuff would see less heat.

 

[HYDRODYNAMIC]

Obviously less is better but does anyone know what an acceptable sustained temperature for these things is assuming you want a similar to OEM lifespan.

Steering rack can live in a pretty hot place on a lot of vehicles. Obciously under the dash column mounted stuff would see less heat.

Industrial motors can work at 180F - 210F without issues. UL lists 160F for motors where human contact is possible.

As mentioned, once they get hot, you're kinda screwed. I wasn't happy at all with mine on my honda sxs. I feel like it's much easier to add cooling to a hydro system than an electric.

Are you sure the motor is overheating by itself or is the battery too low on power and the low voltage / high current is causing the overheating?

 

[patooyee]

Data below was sourced from Ranger Station
EPS from Toyota, Nissan and Kia/Hyundai works in fail-safe. The ECU for the column is mounted remotely and can be disconnected and removed. The EPS from Saturn Vue and Chevy Cobalt has an ECU that cannot be disconnected. They have no fail-safe and a 3rd party eBay control module is needed in order for it to work stand alone.

Not sure what exactly this is saying. But The Vue unit I have in my Rzr does not need an ECU (Engine Control Module) or eBay controller. It runs the stock Vue controller that is mounted to the unit itself and is a stand alone system, not connected to anything but ignition power and battery.

 

[HYDRODYNAMIC]

Not sure what exactly this is saying. But The Vue unit I have in my Rzr does not need an ECU (Engine Control Module) or eBay controller. It runs the stock Vue controller that is mounted to the unit itself and is a stand alone system, not connected to anything but ignition power and battery.

I'm not sure what they meant either. ECU could mean electrical control unit. I wonder if some don't need a box at all?

 

[Satan's_Minion]

125A at 14V = 1750W same as the F150 = 2.34HP
1500PSI x 2.5GPM /1714 = 2.18HP

Just because it has a 125A fuse I would not assume it will consume that much power continuously. I would venture a 80-90A @ 13.5V would be a better estimate. Likely not more than 1.2 kW

And I would guess the pump drive is going to rely on the fluid to cool it at those power levels. That may cause de-rating if you try to use it in an off-road application.

 

[patooyee]

Just because it has a 125A fuse I would not assume it will consume that much power continuously. I would venture a 80-90A @ 13.5V would be a better estimate. Likely not more than 1.2 kW

Regular hydraulic systems don't consume max power continuously either. I think his comparison was just meant to compare peaks.

 

[YotaAtieToo]

Industrial motors can work at 180F - 210F without issues. UL lists 160F for motors where human contact is possible.


Are you sure the motor is overheating by itself or is the battery too low on power and the low voltage / high current is causing the overheating?

No idea, machine is long gone. It did seem more frequent after I added a wiper and heater (using engine coolant, so just running a fan)

Electrical power is a big limitation on sxs's.

As mentioned, I think the idea is cool on something light. I thought about it when converting my samurai to power steering, but the stock sidekick stuff is just too easy.

Am I wrong in thinking that a power steering pump will use more hp than the extra load on the alternator with electric?