DTSFab.com (Desert, Trail and Sand)
UTV's Off Road ( RZR, YXZ, Mini Buggy, Carts,etc.) => UTV Member Project Logs => Topic started by: fabr on September 21, 2015, 05:53:27 AM
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Had you considered just using an electric power steering unit? They work very well.
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Yea, I seen them mate - not a fan because they transfer a heap of load though the steering rack, unis and shaft to the worm and wheel of the rack.
I have make a power steering pump output before - worked well, but very hard on the pump because of the RPM
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Tons of them in use with no issues. Many are on 2000# plus cars. Mine has been going strong for 3 years now. I do agree it adds stress to the steering uj's and rack but there is no parasitic HP loss as there is with driving a pump.
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I hear what you are saying with the losses. I tried my mates electric unit, and I'm really not much of a fan of the feel. He reckons he still gets arm pump to, whereas I feel nothing through my hydraulic unit.
I'm trying to come up with a way to drive it from the trigger wheel stub (with a belt) at the moment. I know someone who has removed the water pump and is driving it though that shaft (no belts), but I'm petrified of breaking the little tang off.
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I don't like the water pump delete thing either. Sounds like something bad just waiting to happen. Not only breaking the tang but having to use an electric water pump as well. Nope,not for me.
Not trying to beat a dead horse ,just discussing ,if you wish. I am using the Unisteer ATV EPS unit. I actually love it. Wouldn't trade it for anything on a 2000# or less buggy. Power assist is truly proportional to steering wheel input . I believe your mate may be using the cheaper,by far, factory unit (I don't recall the cars units that are being used)with the adjustable assist unit that are available. I agree I would not like that . Fastcorvairs make a "rack snuggy" that is a fantastic ,direct bolt on to most r&p boxes used,that takes the slop out of them and is adjustable for wear as well as rebuildable. I'd like to address the concern for additional wear due to increased input from the EPS,FWIW I see it this way, there is likely no more input than you could seriously muscle into it or what it takes hitting a berm or rut. Honestly,on my heavy pig,I have seen no abnormal wear.
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an easy way to know which one he is using is to ask what amp fuse he is running to it. there are 3 used from what i found. the large one from the chevy suv's used a 35 amp fuse and the smaller ones used on the toyota cars like the prius i think are 20 amp fuses. the utv ones are like the prius but diff and i think use the 20 amp fuse as well. the smaller ones are like 16 amp and the toyota ones were like 18 amps and chevy suv which is diff than the chevy car pull 30 amp at full power. there are 2 diff controllers on ebay for the factory eps units.
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SFAIK,none of the aftermarket controllers are proportional. That makes them behave fine in the sand but some have said were twitchy on hardpack or asphalt.
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ya the only part of the controller that you have control of is the amount of voltage/assist so turn the knob and you have more or less. the sensitivity of the motion/tq sensor on the shaft itself was built for a heaver vehicle with the motor in the front. big dave runs the saturn vue eps and he would be a good one to ask how it has worked for him both on the sand and river bottom and prob hard pack and pavement too. now the malibu car's eps i believe is lighter duty but prob reacts the same.
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i too have the saturn vue eps and the controller off ebay but have not installed it on my current rail. since it has a 30 amp draw at full assist i do not believe my charging system can support it. 45 amp rec reg
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ya the only part of the controller that you have control of is the amount of voltage/assist so turn the knob and you have more or less. the sensitivity of the motion/tq sensor on the shaft itself was built for a heaver vehicle with the motor in the front. big dave runs the saturn vue eps and he would be a good one to ask how it has worked for him both on the sand and river bottom and prob hard pack and pavement too. now the malibu car's eps i believe is lighter duty but prob reacts the same.
Without proportional assist it I would tend to agree very much with Simon.
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http://www.ebay.com/itm/Saturn-Vue-Ion-Chevrolet-Equinox-Electric-power-steering-controller-box-EPAS-/171733694488?hash=item27fc203818&vxp=mtr (http://www.ebay.com/itm/Saturn-Vue-Ion-Chevrolet-Equinox-Electric-power-steering-controller-box-EPAS-/171733694488?hash=item27fc203818&vxp=mtr)
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SFAIK those controllers will not operate the EPs proportionally.
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no they just fool the control box or give you the input the pcm would've been sending to the control box. i went on to unisteers site and looked at the models they offer for diff weight class's. now i cannot tell from a picture, but not only does the casing look identical to the chev malibu and saturn vue but even the body where the steering column cover bolts on looks the same. there seems to be 2 wires coming out of the body on one side where the through shaft comes out which would be the shaft sensors ( i believe they are tq sensors ) which tell the control box to add assist but when the ebay harness is added you can adjust what it's set at so not sure how it will work but like i said big dave uses it. it would be interesting to know if unisteer has found a way to make theres proportional and how? fabr does your gear box case have a mfg name on it? is yours the 1700 watt model? the vue would be the 170 watt unit for the 3k lb and under class? the vue would be there equivalent of 220 watt model for the heavier cars.
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No name on it at all. I'm pretty sure that all are basically same internally though. It's the control box ,IMO, that makes a big difference. Of course,many people are "happy" with a Charlynn setup................ to each his own.
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My info suggests that the ebay type control only limits the assist to what you "like" but is not proportional to input.
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i would agree but there is a control box like an ecu on the unit itself that takes the inputs from the tq sensors the internal shaft go threw. i only know this because i took one of my 2 units apart because i wanted to see how it worked. now a unit rated for double or more weight than it's actually being used for would/could feel twitchy simply because it has more power to assist with. i believe big dave runs his full power all the time and i bet that can make it a touch more twitchy? idk just guessing on that one but i will personally find out for the next spring dts run at LS
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Funny ,there's not any real info on this anywhere that I know of. Simon,I'll clean up your thread and split this discussion of EPS from it if that is OK with you.
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Funny ,there's not any real info on this anywhere that I know of. Simon,I'll clean up your thread and split this discussion of EPS from it if that is OK with you.
good idea and wasn't trying to hijack it. i just got home and looked at my unit. i looked at the unisteer again and can see the diff. the unitsteer actually is using a processor where the vue is just a control box more like a relay hub where main power from the batt is attached and the sensors are junctioned to the actual pcm of the vehicle so the the ebay controller is an on off switch with a variable voltage switch which only sets what would be the speed sensitive steering side of the equation ( high speed low speed assist) where the unisteer processor uses the input to smooth the assist into a usable proportional/linear drive.
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That is my understanding. I think the cheap route is perfectly suited to sand. I also think the unisteer unit is the way to go on hardpack of any kind due to the differences you just posted. I further believe Unisteer is making an obscene profit on theirs though..................... I do like the thing in spite of that.
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agreed on both however when it comes time to add mine i am going to look into it a little farther to see if there is an option out there to add the same processor to the vue eps.
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The electric power steering (EPS) system reduces the amount of effort needed to steer the vehicle. The system uses the body control module (BCM), power steering control module (PSCM), torque sensor, discrete battery voltage supply circuit, EPS motor, serial data bus, and the instrument panel cluster (IPC) message center to perform the system functions. The PSCM, torque sensor, nor the EPS motor are serviced separately from each other or from the steering column. Ant EPS components diagnosed to be malfunctioning requires replacement of the steering column assembly, also known as the EPS assembly.
Torque Sensor
The PSCM uses a torque sensor as it's main input for determining the amount of steering assists. The steering column has an input shaft, from the steering wheel to the torque sensor, and an output shaft, from the torque sensor to the steering shaft coupler. The input and output shafts are separated by a torsion bar, where the torque sensor is located. The sensor consists of a compensation coil, detecting coil, and 3?detecting rings. These detecting rings have toothed edges that face each other. Detecting ring 1?is fixed to the output shaft, detecting rings 2?and 3?are fixed to the input shaft. The detecting coil is positioned around the toothed edges of detecting rings 1?and 2. As torque is applied to the steering column shaft the alignment of the teeth between detecting rings 1?and 2?changes, which causes the detecting coil signal voltage to change. The PSCM recognizes this change in signal voltage as steering column shaft torque. The compensation coil is used to compensate for changes in electrical circuit impedance due to circuit temperature changes from electrical current and voltage levels as well as ambient temperatures for accurate torque detection.
EPS Motor
The EPS motor is a 12?volt brushed DC reversible motor with a 65?amp rating. The motor assists steering through a worm shaft and reduction gear located in the steering column housing.
Power Steering Control Module (PSCM)
The PSCM uses a combination of torque sensor inputs, vehicle speed, calculated system temperature and the steering calibration to determine the amount of steering assist. When the steering wheel is turned, the PSCM uses signal voltage from the torque sensor to detect the amount of torque being applied to the steering column shaft and the amount of current to command to the EPS motor. The PSCM receives serial data from the engine control module (ECM) to determine vehicle speed. At low speeds more assist is provided for easy turning during parking maneuvers. At high speeds, less assist is provided for improved road feel and directional stability. The PSCM nor the EPS motor are designed to handle 65?amps continuously. The PSCM will go into overload protection mode to avoid system thermal damage. In this mode the PSCM will limit the amount of current commanded to the EPS motor which reduces steering assist levels. The PSCM also chooses which steering calibration to use when the ignition is turned ON, based on the VIN. The PSCM contains all 8?of the steering calibrations which are different in relation to the vehicles RPO's. The PSCM has the ability to detect malfunctions within the EPS system. Any malfunction detected will cause the IPC message center to display the PWR STR (or Power Steering) warning message.
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http://www.superatv.com/Universal-Power-Steering-Kit-P5150C1039.aspx (http://www.superatv.com/Universal-Power-Steering-Kit-P5150C1039.aspx)
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http://www.superatv.com/Universal-Power-Steering-Kit-P5150C1039.aspx (http://www.superatv.com/Universal-Power-Steering-Kit-P5150C1039.aspx)
http://www.ebay.com/itm/2007-2009-EQUINOX-TORRENT-ELECTRIC-POWER-STEERING-MODULE-NEW-GM-25883854-/261725296382?hash=item3cf00b16fe&vxp=mtr (http://www.ebay.com/itm/2007-2009-EQUINOX-TORRENT-ELECTRIC-POWER-STEERING-MODULE-NEW-GM-25883854-/261725296382?hash=item3cf00b16fe&vxp=mtr)