Was going to do a step by step install pf a Prius electric p/s unit on my forklift but there is no way I can improve on the simplicity or clarity of this guys video. "Suzuki Samarai electric power steering conversion". I can't help if one cannot follow this.
Mike, I'm sure there is an overload by-pass where nothing is damaged if load is too great. The hydraulic units have this which is most put in use when one hits the limiter on lock to lock turns. Often accompanied by belt squeal.
I guess the forklift will be a test as it has no dash at all, just a steering column sticking up through the floorboard and it sits out in all types weather. Might work a week or maybe ten years.
Somewhat off subject, but while searching YouTube, for installations of the Prius EPS units, I ran across a video with a guy installing one in a electric powered vintage Jaguar. The install was slick and in the video, he uses a company that laser cuts metal using your cad drawings. The turn around time was days and the cost reasonable.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
If you notice the EPS (Electric Power Steering) has a CAN (Controller Area Network) bus connection. The CAN bus is a network over which up to 70 ECU (Electronic Control Units) can communicate with each other. Data such as speed, RPM, emissions related sensors, safety etc. is/are shared. Modern cars and trucks have an OBD-2 connection for diagnostics. OBD-2 connects to the CAN bus.
Why do manufacturers have a design where the EPS is connected to the CAN bus connection? Primarily for speed and safety. At 80 MPH you don't need a steering system that feels too responsive "whippy". At 10 MPH you don't need a steering system that feels like an original 50's AD with super wide tires. For safety, the system needs to know when the brakes are applied.
So what's my point? This discussion is in the Driveline section of Stovebolt and not the HiPo section. Steering is the #1 priority. If you install EPS in another application or modify it with your own design, you take on the legal liability. There is more to EPS that what you learn on a video link. Don't go at it blindly. Do some research and play safe.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
If you notice the EPS (Electric Power Steering) has a CAN (Controller Area Network) bus connection. The CAN bus is a network over which up to 70 ECU (Electronic Control Units) can communicate with each other. Data such as speed, RPM, emissions related sensors, safety etc. is/are shared. Modern cars and trucks have an OBD-2 connection for diagnostics. OBD-2 connects to the CAN bus.
Why do manufacturers have a design where the EPS is connected to the CAN bus connection? Primarily for speed and safety. At 80 MPH you don't need a steering system that feels too responsive "whippy". At 10 MPH you don't need a steering system that feels like an original 50's AD with super wide tires. For safety, the system needs to know when the brakes are applied.
So what's my point? This discussion is in the Driveline section of Stovebolt and not the HiPo section. Steering is the #1 priority. If you install EPS in another application or modify it with your own design, you take on the legal liability. There is more to EPS that what you learn on a video link. Don't go at it blindly. Do some research and play safe.
I would question how much research you have done on this, despite urging others not to.
An EPS in failsafe mode (no CAN connection for any external vehicle information) behaves the same as any power steering system made in the last hundred years. It has a fixed amount of assist no matter what speed the vehicle is going. Adding speed sensitivity and/or wheel angle sensors allows for interesting additional features like the variable assist that some vehicles have, but those are very much not necessary as evidenced by the prevalence of saginaw based steerings that have not killed us all.
I am honestly curious why you think the steering needs to know if the brakes are applied. I have never seen that come up in any of the research I have done.
Making any kind of change to a vehicle from tire size on up theoretically opens you up to legal liability. No one complains about adding power steering by using the late model steering boxes despite that being an equally large change.
I added a picture of the diagram (red box) showing the CAN bus connector.
As far as I know there is no failsafe for the failsafe. All your eggs are in one basket. I suppose, but do not know, if failsafe failed one could strong arm the steering wheel to steer the car/truck over to the side of the road...if you have your wits about you. Unfortunately the little old lady with arthritis may find it a problem. I don't know if it would pass DMV regulations or if you can convince your insurance company it was safe. All I can do is raise warnings in hopes of being helpful for the unforeseen.
I do have experience in replacing a gear box, with multiple gears, with individual position-control motors that are controlled by a PLC.
Why does the EPS need to know that brakes have been applied? Doesn't the question prove the point I was trying to make about technology?
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
The failsafe for the failsafe is the exact same as a vehicle with hydraulic power steering...there is no longer power steering. Same as if the engine died while going down the highway with hydraulic, you would be 'strong arming' in that situation as well.
The failsafe for the failsafe is the exact same as a vehicle with hydraulic power steering...there is no longer power steering. Same as if the engine died while going down the highway with hydraulic, you would be 'strong arming' in that situation as well.
Precisely. If you had researched it, you would know that the shaft is solid all the way through with what amounts to a strain gauge to measure torque on the wheel and a closed feedback loop to apply force to reduce that torque. The sensor is electronic, not purely mechanical. Other than that, it is fundamentally the same implementation and failsafe as 95% of the vehicles on the road today. There are people who think that electronic sensors are bad, but they are often the same ones who think carbs are better than fuel injection.
And where is the evidence about the brakes having any relation to the steering? Yes, it has a connection to the CAN bus. Where it reads the vehicle speed to allow for clever tricks. You could just as easily ask why the radio needs to know that the brakes are on because it is also connected to the CAN bus. Or why the engine computer needs to know that the turn signals are on.
Lets say little old ladies can steer an EPS with a failed failsafe a lot easier than a hydraulic system with broken belt. I would, at very minimum, run it past the insurance company to make sure they will provide coverage on an automobile with that kind of modified steering system.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
I would, at very minimum, run it past the insurance company to make sure they will provide coverage on an automobile with that kind of modified steering system.
Is adding electric power steering any different that installing a Mustang II front suspension to an insurance company? How many trucks/cars are running around with those installed?
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
Precisely. If you had researched it, you would know that the shaft is solid all the way through with what amounts to a strain gauge to measure torque on the wheel and a closed feedback loop to apply force to reduce that torque. The sensor is electronic, not purely mechanical. Other than that, it is fundamentally the same implementation and failsafe as 95% of the vehicles on the road today. There are people who think that electronic sensors are bad, but they are often the same ones who think carbs are better than fuel injection.
And where is the evidence about the brakes having any relation to the steering? Yes, it has a connection to the CAN bus. Where it reads the vehicle speed to allow for clever tricks. You could just as easily ask why the radio needs to know that the brakes are on because it is also connected to the CAN bus. Or why the engine computer needs to know that the turn signals are on.
I've researched quite a bit which is why I pulled a column and module from a 2010 Corolla back in September. $62 at the Pick Your Part for power steering with (hopefully) much less hassle than moving the steering box and adding a pump! I also thought about going the hydraulic route using an electric p/s pump from a Volvo but I would still have to get a new steering box. I've read that the Volvo pumps sound like the whine from the DeLorean in Back to the Future and would rather not have that (although that would sound neat like once). The EPS just makes sense.
You are right about all of the connections (brakes, speed, etc.), they are there only to increase or decrease the assist in certain situations and are not needed unless you want adaptive steering. The failsafe mode works at the same assist level needed for around 40 MPH at all times. I'm perfectly fine with that.
These are the Toyota/Nissan/Kia units that have built-in failsafe. GM units can be used but require the use of another module that tricks the unit into thinking the vehicle is travelling at a certain speed and have a potentiometer that makes for adjustable assist but I personally don't want that extra layer of complexity.
Seems to me that if you put the Prius setup in a 2-ton loaded dump truck and you hit a curb funny while holding onto a 20" steering wheel, something is going to give. The larger the trucks are the bigger the steering setup is, so something designed for a 3000 pound car might turn into a pretzel if installed in a 16000 pound truck.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD
You would definitely want to size the donor EPS for the truck. The coupling joints alone need to be sized correctly.
Sorry, back to the failsafe discussion (mental punishment). I don't know the answer to this question but suppose the failsafe failed and the circuit for torque assist somehow went nuts forcing the steering wheel right (meeting oncoming traffic). You have the "shaft is solid all the way through" resistance plus the torque assist in the wrong direction, would a person still be able to steer safely? I'm past the point of criticizing and insurance warning. I'm now just curious.
If the above happened and if it is significant, I would think using a "brake" signal via the CAN bus to deactivate the torque assist would be a needed safety feature.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
This all looks and sounds great by using modern technology, but. There is an overriding issue to be determined. What is the condition of the steering box? This system simply backs up the manual steering box. If the reason to install any PS is because the steering box is worn out, the electric or an earlier control valve/ram assist won't solve the problem. If the steering box, tie rods, king pins, wheel bearings, wheels and tires are good, it makes perfect sense. Fred
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes 1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes 2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans 1947 Willys CJ2A w/F-Head engine
