Volvo EPAS Conversion

[Dirtman]

I'm honestly a little confused what this conversion is? Anyone wanna give me the cliff notes?

On my old ramcharger there was a semi common mod to tap the power steering box at very specific locations, then run lines to a hydraulic ram attached to the drag link. The steering box fed the ram and basically split the power. It eliminated bump steer, stiffened the steering, and gave more power. Not street legal in the slightest and if you weren't use to it, it was confusing. (The steering would not return at all).

 

[Jim Oaks]

Your Rangers power steering pump is turned by a belt attached to the motor.

This pump is electric. Works the same way, but is self propelled.

Benefits:

No more noisy power steering pump.
Power steering works even if the engine is off.

 

[Dirtman]

Your Rangers power steering pump is turned by a belt attached to the motor.

This pump is electric. Works the same way, but is self propelled.

Benefits:

No more noisy power steering pump.
Power steering works even if the engine is off.

Gotcha, my fiesta has an electric system like that. I really hope the Volvo system is better... my car handles like garbage.

 

[bobbywalter]

For curiosity's sake, how would this work powering steering and say hydroboost?

Obviously as it varied so would the brake assist, but how much?

we will find out soon. my truck has hydro boost and i need a ram.

This is interesting and a good alternative to using an inline electric power assist motor in case you want to keep hydraulic assisted steering. Can't wait for the article to be finished.

or electric steering and hydro brakes. totally shrink off the fead. and fit big blocks(think 460-5.4 dohc-coyotes.....or....mmmmmmmm the new big daddy 7.3 commercial engines over built for supercharging......

with what you and petro junky are bringing into the fray here.....we can drop these bastards in these rangers like they were briggs and stratton engines.


you guys rock

 

[Uncle Gump]

you guys rock

I agree... both systems open up some possibilities we didn't have before. Thanks for sharing what you do...

 

[PetroleumJunkie412]

Appreciate it. Should have the rest finished by tonight. My biggest problem was how few photos I took during the install, so may have to use some found ones.

I priced one of these pumps new on Rock Auto. $199.00.

Yeah, they are not cheap to buy a new one. Occasionally you'll see one on eBay for 80-120. Like everything Volvo, they're not cheap to keep up with. Failure rate seems to be seldom, though.

Gotcha, my fiesta has an electric system like that. I really hope the Volvo system is better... my car handles like garbage.

Not sure what the Fiesta is using. May look that up. What year and trim?

This one feels like a cross between a manual and power setup. Plenty of road feel without feeling too light or too heavy. Just isn't very responsive when sawing on it quickly. Good trade off in my opinion.

I really want to experiment with some of the additives to see what it changes.

 

[Dirtman]

2017 ST, but it has the "S" rims and tires so to be fair the terrible handling probably has more to do with the micro economy tires than the power steering system.

 

[BlackBII]

The Fiesta uses a manual steering rack and pinion with an electric assist in the column, no hydraulics.

 

[four.on.the.floor]

I also look forward to this also !

 

[Nez'sRanger]

I hope some of our guys can solve the CAN BUS mystery... Nobody on the web seems to be able to plug a multimeter into their working s40 and see what signal the CAN is altering to adjust pump power. It would be pretty darn sweet to be able to have a knob on the dash to make it more or less sensitive on the fly.

 

[19Walt93]

Wouldn't it be simpler to adapt a Saginaw pump to the Ford brackets rather than using an electric pump? That would cure the C2 pump whine.

 

[Nez'sRanger]

Wouldn't it be simpler to adapt a Saginaw pump to the Ford brackets rather than using an electric pump? That would cure the C2 pump whine.

For sure, but, I'm personally interested in eliminating another accessory pulley from the engine, as well as the ability to have power steering with engine off (especially nice during stalling and engine malfunction). Only an electric pump can give those benefits. I'm hoping it can free up a little power, similar to the electric fan conversions.

 

[PetroleumJunkie412]

It frees up a noticeable amount of power. Costs involved with electric conversion are way cheaper at the JY vs a Saginaw.

I really need to finish this.

 

[alwaysFlOoReD]

Yes, you do. Get on it!

It frees up a noticeable amount of power. Costs involved with electric conversion are way cheaper at the JY vs a Saginaw.

I really need to finish this.

 

[adsm08]

I hope some of our guys can solve the CAN BUS mystery... Nobody on the web seems to be able to plug a multimeter into their working s40 and see what signal the CAN is altering to adjust pump power. It would be pretty darn sweet to be able to have a knob on the dash to make it more or less sensitive on the fly.

That would roughly be not even remotely how a can bus diagnostic would happen. In fact, a voltmeter or multimeter is nearly incapable of registering network signals, let alone decoding them and seeing the contents.

The average multimeter has a response time that is measured in halves of a second or so. CAN activity happens on the order of micro-seconds. By the time your meter can respond the signal has come, gone, and been forgotten, and that the low-speed network. To even see the signal activity expressed as voltage spikes you need an oscilloscope. To see what commands are being sent you need a good scan tool that plugs into the network.

I don't know the specifics of the Volvo system, but Ford owned Volvo in the time period in question, so I can make some good guesses about the design and network strategies in question.

The EPAS unit is probably a module in it's own right, able to see and respond to networked commands from other modules. There is probably a steering wheel rotation sensor on the column of the S-40, which likely takes the form of a shutter wheel and magnet, similar to an old track-ball mouse. We also have an ABS module, or a PCM, or both, monitoring and sending vehicle speed data across the nework.

Likely what happens is that the EPAS module is monitoring steering wheel rotation signals for direction and intensity, and vehicle speed data, and using those with a pre-determined set of values, against tire size, to calculate and command a duty cycle to the electric pump, which then allows for variable steering assist.


Ford used a very similar system on the Crown Vics, but instead of an electric pump there was a variable orifice on the steering lines that would regulate the amount of fluid, and thus pressure, allowed to flow to the gear, and that allowed for some degree of modulation of the steering assist. It basically had two positions, high and low assist, and you could feel it switch around 35 MPH, if you paid close attention.