Magnetorheological Suspension on a Trac

bajallama

New member
A project that has been stirring in my head for a while involves the use of magnetorheological shocks on my AllTrac. It’s the use of ferrofluid to change dampening characteristics of a damper almost instantaneously. Basically I can have a Skyhook style suspension system that will package and respond eleventeen times better then that funky Tein EDFC chingis. These shocks can react in real time and paired with a good spring, can provide the most ideal suspension characteristics not only in jounce in rebound but in a dynamic response to roll, dive and squat. Along with a speed signal, suspension characteristics can also change. There is no High and low Speed dampening, there is “All speed” dampening I guess you can say. Why hasn’t anyone made an aftermarket coilover utilizing this great discovery? I don’t know. I do know that the shocks do undergo a lot more wear and from the forum complaints I have seen, the fluid destroys the seals and may give you a max of 80k out of it. Most people replace the system with regular gas shocks and a fake out resistor for the controller. I have disassembled one of the shocks and will show some pictures of what it looks like inside once I get them uploaded. The shocks I chose are the front’s off of an Escalade/Denali and picked a pair off Craigslist for $150. The idiot said they were barely used but he just cleaned them up because the seals are shot. I did notice they are held to an initial pressure with gas. It’s not very high and it’s necessary to maintain some characteristic in the fluid. I think it has to do with settling of the iron particles but who knows. I will be establishing that when I go through the tests. I am currently designing a shock dyno to go through re-engineering the shock.

shockdyno.jpg


These things work on a simple PWM circuit so I will have an Arduino control that along with an Arduino as a makeshift DAQ for the load sensor and linear potentiometer. Ya, I'm ballin on a budget again, buying these Arduino's from China for $3 each along with a used 500lb eBay load sensor(last calibrated 10 years ago), a junkyard linear potentiometer(last calibrated????) and an eBay Pneumatic ram (not purchased yet).

If any of you have some input, I would greatly appreciate it! I am also concurrently working on a 4th gen 3S swap so progress will be slow at first but hopefully pick up. I'll try to document as much as I can and hopefully can be an interesting and educational read.
 

CMS-GT4

Active member
I am interested to see how this turns out for you. I considered this when I was hunting suspension, but I could not find Donor shocks for a cheap enough price for the experiment. I thought GM bought the company with the patent, so that may explain the lack of aftermarket.

Do you think the Arduino is fast enough to deal with the data? We have talked about the Arduino for other purposes like EGT, and some claim there are other ECUs that are simpler, and faster processing. It might be something to consider. I am curious if you could find a gm car that is being parted out and get a hold of the control center for the mag ride, and see if it could be hacked.
 

bajallama

New member
CMS-GT4":3mge6yna said:
Do you think the Arduino is fast enough to deal with the data? We have talked about the Arduino for other purposes like EGT, and some claim there are other ECUs that are simpler, and faster processing. It might be something to consider. I am curious if you could find a gm car that is being parted out and get a hold of the control center for the mag ride, and see if it could be hacked.

Cool man! It's nice to see someone has also had an interest in it. The patent is owned by the BWI group and the work out of China. They sell shocks to not only GM but Land Rover and Ferrari. I was researching the patents and the actual design of the shock is what is patented and there are multiple of those (I even have thoughts of designing my own eventually). The fluid is made by LORD corp in the states and was developed in the 1960's. It hasn't found a use since it is really harsh on machines during manufacturing and technology has finally caught up.

Arduino Nano is 16MHZ and that's fine as long as the code is light. For now I am just planning to make an on the fly suspension adjuster using a dial or whatever. I don't think I'll have any feedback, yet. They are probably right, I heard the Arduino IDE downplays the AtMega chip pretty bad, but I am self taught and that's all I know right now. I made this cool clock that has a temp gauge and altimeter in my 165 and it works really well except for some bugs in the code:

http://www.projectz61.com/design/celica ... metertemp/

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Also made this pressure gauge with one:

ard1.jpg


I have no idea how to even start to hack one of those computers! Haha, if you have any experience with that kind of stuff, that would be cool.
 

underscore

Well-known member
What did the oil pressure setup cost to make? I want oil pressure and temp gauges with warnings but premanufactured ones are pretty pricey.
 

bajallama

New member
underscore":3hcrqtkt said:
What did the oil pressure setup cost to make? I want oil pressure and temp gauges with warnings but premanufactured ones are pretty pricey.

It cost about $35 but I had to 3D print a carrier, if you're interested email me weedletrainer@gmail.com I can give you a list of parts or send you everything, I have a bunch of extras laying around. Oh and you have to buy whatever sensor you plan on using on top of that.
 

bajallama

New member
I took apart one of these shocks a couple months ago and as I expected, it's super simple. The piston is basically a coil and has multiple layers and passage ways for the fluid to transfer. The piston is really tight tolerance and rides inside the machined housing without a seal. I was surprised how low the wear is on the machine wall.

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Domspun

Member
Very interesting, I love adding new technologies to older cars. I always wanted a comfy ride in my street ST185, but all I got is cheap coil-overs.
 
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