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EPS (electronic power steering) conversion for FD

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Old Mar 12, 2012 | 11:31 PM
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EPS (electronic power steering) conversion for FD

I was considering using an rx8 power steering rack and control module in the fd as I already have an aftermarket 20b subframe and we are pushing the motor back into the firewall. There should be enough room. I also found this system from flaming river
http://www.flamingriver.com/index.ph.../s0001/FR40105 although the price is quite over the top. which is why i would like to try to adapt the rx8 EPS system.
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Old Mar 13, 2012 | 08:03 AM
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First off, you'll get a zillion replies telling you to ditch the power steering .

Second, that Flaming River kit looks like it's designed for domestics with a steering box. It replaces and boosts the steering box. That's agricultural technology with an electric motor attached, no way Jose.

I seem to remember the RX-8 rack attaches to the subframe quite a bit differently than the FD rack, but you do have a custom subframe, so there's that. I also don't know how much juice the rack requires, you might need a bigger alternator.

I imagine in whole it would be less weight than the hydraulic rack.

Unfortunately, you're blazing new ground here. I'd get my hands on the RX-8 shop manual and study that system, find out how all it works, see if you can get a used rack cheap to try and mock up, and go from there.

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Old Mar 13, 2012 | 10:39 PM
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my reason for doing this is not for freeing up horsepower it is simply to clean up the engine bay my 20b is not using a/c and being able to remove the power steering pump I feel would clean up the engine bay. My ultimate goal is to simplify the engine bay as much as possible. So the idea of using one belt and leaving a lot of room to work seems very appealing.
I believe you are correct regarding the flaming river being designed for domestic vehicles but it seems that if I convert to a manual rack I could modify the mounting brackets for the flaming river steering box and possibly use it.
However I would rather use the rx8 system as it seems like it would be cheaper. as I have access to an rx8 parts car . The question is how does it work? and how can I get the power steering control module to ignore its factory lockout system as it will not be used with the rx8 ecu. also I have to try to figure out how it determines vehicle speed. is it a voltage rheostat based upon speed or a pulse system. Hopefully someone with more experience with rx8's will chime in.
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Old Mar 14, 2012 | 01:42 AM
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Why not just use an mr2 electric pump?
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Old Mar 14, 2012 | 06:32 AM
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https://www.rx7club.com/fabrication-250/write-up-mr2-electrical-power-steering-conversion-847818/

Check this thread out. Has some info on the MR2 swap. Might be a better option.



John
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Old Mar 14, 2012 | 07:51 AM
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The Flaming River kit requires drag links and the like. You're looking at a net addition to your engine bay with that kit, and I don't think you'll be able to fit all the linkages into your space available. You'll basically have to cut off the frame rails and custom fabricate new ones to make space for that kit.

Now with the RX-8 setup, i'm not sure. As Dale said, study the FSM and get a cheap used unit, just to see if you can mock it up.
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Old Mar 14, 2012 | 08:13 AM
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Ill be the first to say it, just go manual rack. It really isn't any harder to steer maybe in like 2% of driving. I was worried when I went manual, but now I will never go back to power steering.
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Old Mar 14, 2012 | 08:21 AM
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I agree. I went with the manual conversion from Maval and don't miss power steering at all. Will never go back.
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Old Mar 14, 2012 | 09:09 PM
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The electric power steering on the Rx-8 is awesome. I definitely prefer the steering feel of an Rx-8 to an FD Rx-7 (I also like an FC's power steering better than the FD's).

The short answer is that even if you could physically mount and wire up the Rx-8 system, I suspect the control module would go into fault mode without receiving the proper CAN signals. Most new vehicle stuff is going to do that, so swaps of almost anything are becoming more and more difficult.





Here's some further explanation about the control module. It needs to get a vehicle speed sensor from the ABS/traction control system and it would also probably have a generic CAN communication error since it doesn't see the other modules on the bus. You would need access to the proper knowledge and equipment to open the flash memory ROM inside the module and reprogram it so it doesn't go into fault mode. Then you would have to feed it the signals it needs--you'd need to know the proper commands. There's no real easy way to reverse engineer that without software like CANalyzer, and a test rig where you listen to CAN signals across the bus in an effort to isolate what signals correspond to particular sensor values.
Attached Thumbnails EPS (electronic power steering) conversion for FD-rx8_eps_1.jpg   EPS (electronic power steering) conversion for FD-rx8_eps_2.png  
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Old Mar 15, 2012 | 02:49 AM
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don't deal around with an electrical steering rack from another car!
Even if you can mount the rack in the sub frame, the system will not work because of missing input-parameters! (as arghx already explained in a very simple way)
Also, the steering rack will be (damn sure) in another position as the stock FD rack... you will mess up your bump-steering behavior!

We've experimented with an electro hydraulic pump from an Opel in a friends FD! Seems to work (never driven it yet), that's the only clean way to get rid of the stock PS pump, but keep a PS system...

just be a man and go manual! win/win situation... cleaned up bay, less headache about another system, losing weight, train your body in parking situations
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Old Mar 15, 2012 | 08:43 AM
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Has anyone ever tried contacting Mazda, particularly Mazdaspeed, and just asking for help on things like this? If they would help out by handing over the CAN protocol, it would be relatively easy to incorporate into a lot of modern ECUs. I can't imagine that the CAN signal/protocol would contain anything "top secret" that would make them hesitant to share it.

Personally, I'd love to be able to integrate the whole Rx-8 ABS/traction control/EPS architecture into other vehicles. I know I'm not alone in that.
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Old Mar 15, 2012 | 09:34 AM
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Before even think about things like these (ABS/traction control/esp integration) you better get in touch which someone working on an OEM and talk with him about the time involved to set up such a system.

every car reacts differently regarding their, for example, self-steering properties! It also depends extremely on the used wheel/tire combination...

you cannot slap such a system into a car thinking that this stuff will work as long it get's data input...

That’s like putting a haltech onto your 13b, wire it up so it has all needed inputs, setup all sensors and then load a spark/fuel map from a 2jz single turbo car 0.o

Best solution -> ditch every electronic assist systems and educate people how to drive safely...
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Old Mar 15, 2012 | 10:55 AM
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Originally Posted by SpAm@FC
don't deal around with an electrical steering rack from another car!
Even if you can mount the rack in the sub frame, the system will not work because of missing input-parameters! (as arghx already explained in a very simple way)
Also, the steering rack will be (damn sure) in another position as the stock FD rack... you will mess up your bump-steering behavior!

We've experimented with an electro hydraulic pump from an Opel in a friends FD! Seems to work (never driven it yet), that's the only clean way to get rid of the stock PS pump, but keep a PS system...

just be a man and go manual! win/win situation... cleaned up bay, less headache about another system, losing weight, train your body in parking situations
+1

Engineering an electronic rack is just not needed. There are many other options that ALL work great.

PRICEY
https://www.rx7club.com/showthread.php?t=832782

LITTLE CHEAPER
https://www.rx7club.com/showthread.p...ht=manual+rack

EVEN CHEAPER, DIY
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-de-power-your-steering-rack-942543/

NO COST
https://www.rx7club.com/showthread.p...ht=manual+rack
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Old Mar 15, 2012 | 04:30 PM
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Originally Posted by Oscypek1007
Ill be the first to say it, just go manual rack. It really isn't any harder to steer maybe in like 2% of driving. I was worried when I went manual, but now I will never go back to power steering.
Yeah, the 2% of the time the car is turning lol. I've driven both power and manual steering rack rx7's, and I wouldn't even consider daily driving a manual rack. People will try to say its only harder when you are going slow which is complete bullshit. High gforce corners makes the wheel hard to turn, and ultimately ruins the fun of the car as maybe 1 in a 5000 rx7 owners will actually track the car at a level where the weight makes a difference.



The MR2 setup looks interesting. Anyone with feedback over time that has that rack?
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Old Mar 15, 2012 | 06:05 PM
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Originally Posted by rcracer_tx
Yeah, the 2% of the time the car is turning lol. I've driven both power and manual steering rack rx7's, and I wouldn't even consider daily driving a manual rack. People will try to say its only harder when you are going slow which is complete bullshit. High gforce corners makes the wheel hard to turn, and ultimately ruins the fun of the car as maybe 1 in a 5000 rx7 owners will actually track the car at a level where the weight makes a difference.



The MR2 setup looks interesting. Anyone with feedback over time that has that rack?
Sounds like you need to hit the gym son...

I have zero complaints.
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Old Mar 15, 2012 | 07:57 PM
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Originally Posted by DriftDreamzSS
Why not just use an mr2 electric pump?
Try finding one. They are rare and expensive, I spent a fair bit of time trying to track one down.

I also tried ordering a rebuilt one from Autozone. Cancelled the order after 3 weeks, because they don't get them either.
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Old Mar 15, 2012 | 08:02 PM
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Originally Posted by XLR8
Sounds like you need to hit the gym son...

I have zero complaints.
He was right - manual steering is not for everyone.

For instance, bolt on some Hoosier 285/30/18 A6's on each corner, and try that with a manual rack at an autox. You will be slow.

And no, I don't need to hit the gym.
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Old Mar 16, 2012 | 11:13 AM
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if you want to get nuts you could try fitting a vauxhall corsa electrically assisted steering column to a manually setup FD rack. There are a couple of aftermarket controllers as well. This would eliminate all of the associated hydraulics and create a tunable power assisted steering setup.
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Old Mar 17, 2012 | 06:24 PM
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I going to keep pursuing the EPS system from the rx8 I will install the rx8 rack into the fd and use it without power until im able to get it running. even if I can just get it running for 25mph and below would be great.
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Old Mar 19, 2012 | 09:37 AM
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The new RE-Amemiya Super NA7 has electric power steering:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/re-amemiya-naturally-aspirated-super-na7-983477/





Don't have any more info than those pics though.
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Old Mar 19, 2012 | 07:13 PM
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So it has been done! the next question is how did they do it?
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Old Mar 20, 2012 | 10:39 AM
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Originally Posted by rotorooter93fd
So it has been done! the next question is how did they do it?
it looks remarkable like the vauxhall column i previously mentioned, but what do i know.

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Old Mar 20, 2012 | 05:23 PM
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Chevy Cobalt has steering column electric assist like pictured in the last two pictures. Last time I looked into it Google came up with a couple people trying them out on other cars.
I do seem to remember there was a recall associated with them though. This could be good if there are lots of them selling cheap because they didn't work as expected in the OEM application or it could be bad if they were recalled because they just didn't work at all.

I saw one auto crosser used hydraulic steering column assist designed for circle track. He complained it had different assist on right and left turns though.

I was also interested in the electric motor driven remote hydraulic pumps to use with the oem power rack. I have spoken to an auto crosser that has used both the MR2 pump on one car and then the MRS pump on his latest car.

The MR2 pump is getting pretty rare/expensive, is big, ugly and draws 80 amps; however it certainly is proven to work well in many applications.

The MRS pump is compact, pretty, cheap, has integrated fluid reservoir, has easy 3 wire hook up and draws much lower current on demand basis.

The auto crosser I spoke to about it did say it has a weird feeling heavy feeling right off center as it switches from no assist to assist. I don't imagine that would fly in the OEM MRS application, so it might take a bit more set up to get a better feel.

The Electric Vehicle (EV) community is a wealth of knowledge on electric power steering conversions.
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Old Mar 21, 2012 | 12:49 PM
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Ok fcnared you offered no photos before and I had no idea how simple your setup may or may not have been. Thank you for the photo. I agree you are probably onto something here. What is availability of that part? How difficult do you think it would be to retrofit it in the car. As far as wiring is concerned?
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Old Mar 21, 2012 | 01:21 PM
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check ebay UK for the column, they can be found for a deal sometimes. Shipping won't be pleasant, but not too bad either. you'll want a controller for it, such as this

http://www.rallywiz.com/Shop/index.p...od&productId=2
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