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.

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.

Dale

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.

Why not just use an mr2 electric pump?

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

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.

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.

I agree. I went with the manual conversion from Maval and don't miss power steering at all. Will never go back.

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.

https://www.rx7club.com/attachment.p...1&d=1331777337

https://www.rx7club.com/attachment.p...1&d=1331777337

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.

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 ;)

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.

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...

+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

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.

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.

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.

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.

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.

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/

https://www.rx7club.com/attachment.p...1&d=1326382392

https://www.rx7club.com/attachment.p...1&d=1326382392

Don't have any more info than those pics though.

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.

http://www.bradgatemotors.co.uk/spar...mn_fl81346.jpg

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.

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?

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

according to the research I gathered there seem to be a lot of failures and seriously dangerous issues not just with the vauxhall system but all other similar systems. kind of a bummer... I going to look for a small electric motor to my stock power steering pump and relocate it under the frame rail just ahead of the rack and try to hide it just out of view to clean up the engine bay. I believe that I may be able to adjust the speed of the motor by voltage supply to it so that it spins at the same speed as the pulley would normally spin it.So basically im going to attempt to make a electro-hydraulic system but much smaller and hopefully lighter than the mr2 system and a unit that wont draw as much current.

http://www.mazdaspeedy.com/2011/11/t...-steering.html

MRS pump, controller and reservoir in one small package.

Attachment 718370

Maybe I'm in the minority in this thread (or silent majority of people not posting) but I love the FD's steering. Out of many production cars that I've driven over the years, it remains one of the cars with excellent steering feel. I feel no need to change that for the sake of another mod. :)

Hmmn, I hate the numb FD power steering feel.

I really like the feel of my Mazda3 power steering.

So has anyone done the GM EPAS on FD?. My car has Atomic Rex rack and the 4 pro drivers who have driven all said it would be faster with Power Steering

Hey guys, which are the best options these days for a donor electric power steering pump?

None. Delete it. Your don't need it. I'm using a 2xxmm wheel with no ps with 255 fronts on a 9.5j and even at a stand still it requires very little effort. Then of course while driving there's no difference. The power plant is behind the strut towers. There's relatively very little weight on the front wheels. I'm not a very strong person but even at my ride height and with an ultra small steering wheel, I exert very little effort to control my car. Delete it and never look back

Wouldn't necessarily say it's the best - or road legal, but a Sydney based FD runs a Toyota Corolla based system without having to deal with the CAN complications. There was some thought of using Yaris components, but with slicks on biggish rims, the slightly heavier system was deemed a safer bet.

Road legal? There's no law or direction that says a car has to have power steering. You know there were cars produced without it right? Most recently the Alfa Romeo 4c. Naturally there is some reluctance in removing the system but if you give it a try, you'll see there's nothing to worry about. If you can bring in all the groceries in one trip then you can drive an fd without ps. If it's any consolation, my Integra is much more difficult to drive without ps than the fd. It has a manual rack, a large stock steering wheel, sits pretty high and is on 205s on a 7j. That car requires some effort to steer at a stand still. Hand over hand type stuff. I filled the ps rack on the fd with grease and left the feed and return lines open. It's very easy to drive and has a nice weight to it.

^He's talking about Australia which some areas have some pretty intense laws on modifying cars. For example, you can't have an open-air vented BOV, that will get you in trouble. There may be more of a vehicle inspection or something that could be the problem here.

Dale

I agree there is no issue driving without power steering on an RX-7.
I had a 400rwhp FC for 15 years that came from the factory with no power steering.
It was a bit of a bother leaving coffee shops with hot coffee in one hand, but I got through it.

The issue is if you want to drive an RX-7 fast/over the limit with no power steering.
I didn't have the strength to make corrections fast enough when things went wrong with wide sticky rubber up front. I could usually make two big corrections, but got behind on the third.
I wasn't able to drive through a slalom as fast as the car could- just physically couldn't muscle the wheel fast enough.

I do have friends bigger and stronger than me that might be able to do it, but they don't fit in an FD anyways.

In the case mentioned, the steering column is cut open and modified, it's somewhat like the RE car further up the thread when installed. I'm not sure how well the collapsible component fares, there would no doubt be questions asked in a major accident post mortem by the police and insurers if an engineer didn't sign his life away approving the installation.

Interesting most of the track cars here that tried the cheap manual conversion went back to ps, probably due to the stickiness of the tyres. Munroman above sold his v8 car a couple of years ago, but even with the "proper" full rack manual conversion, I also independently heard, a very accomplished driver he did an event with, thought it was pretty ordinary compared to the stock system on track....and slowed the lap time.

oh..... oops. Sorry. I thought he was talking about Sydney as an example. My fault for assuming he was in America. We can't see locations on mobile so I play the numbers and figure everyone is in america.

I threw one of these on our super production car a few years ago:

https://www.ultimatepowersteering.co...ering-columns/

It works well,

The easiest OEM system to adapt (that I've found) is an EHPS pump from a Holden/Vauxhall TS model Astra. This is made by TRW. It has an onboard computer that regulates pump output based on steering demand (system pressure). Because the pump is entirely self-regulating, all it needs is power, ground and ignition sense, making it simple to wire up and no need for CAN integration or mocking vehicle speed input signals. It also has an inbuilt reservoir. I found one locally for $100 complete with mount, lines, fittings etc.

https://cimg2.ibsrv.net/gimg/www.rx7...457575f6c4.jpg


The only problem for most guys here is that this car was only in RHD markets. That said, you could probably import one from Europe or Australia. It's also probably easier to find than the MR2 ones, which were hard to locate when I was looking (and inferior to the Astra pump anyway).

Thanks mate that is exactly what I was looking for! :) I love where you mounted it too.

How many amps does it draw?

Did you join the new lines to the existing hard lines or straight to the rack? Do you have some more pics?

No problem - glad I could help.

This was not my install. Mine's going in soon and will use a similar location (but I'll fabricate a stone guard). This photo is from this build: AusRotary - Login

That build thread show the correct way to hook it up.

Also check out the diagrams here: FC power steering questions? - Page 2 - AusRotary

I'll be sure to put up photos of my setup once it's done (will be a few months though).

This pump has an 80A inline fuse, but peaks at 60A (likely for only for short periods, peaking when it initially speeds up) and 7.5A at idle. The Astra initially came with a 70A alternator originally, but I read the Holden service bulletins and they had some issues with flat batteries so they up'd the rating. I'd want at least a 100A alternator from an FD to be on the safe side. the 80A alternator from a s5 might just cut it (depending on thermo fans, fuel pump etc).

There are 3 different types of pumps from the TS Astra - you want the smooth case with the round reservoir as shown above. There is another version with a heatsink base, made by Delphi. These suffered failures. Later models are also no good as they require a speed signal input. These pumps requires specialised hydraulic fluid - equivalent to Pentosil CHF 11s. Penrite makes an fluid which is compatible (Penrite LDAP).

The other thing to note is that it needs a restrictor in the fluid return line - there is actually one in the factory lines, so if you get these, keep the restrictor to mimic the factory setup.

Hope that helps!

PS. For people looking for these in Europe, the model is a Vauxhall Astra G (not TS). TS was the Australian Holden model code.

Awesome thanks heaps!
Is yours going into an FC or FD?

neither! Series 3 with series 5 subframe and power rack and pinion conversion.

Haha nice.
Does the FD have this restrictor in its return line too?

I'm not sure, but it's probably irrelevant. It was the Astra return line that had a restrictor in it. You need to re-use this restrictor in the return line you fab up for the conversion. I suspect the restrictor helps maintain line pressure, which in turn helps the responsiveness of the pump and degree of assistance it provides. A few people have written on forums that they had delays before the pump kicked in, which were resolved by putting the restrictor in. It will also help to keep the lines short, but that's difficult with the location of the steering rack input relative to a RHD RX-7 engine bay. The best spot for it is probably somewhere on the front passenger side.

Has anyone tried to adapt US GM epas components? From Saturn or many other 2010+ cars? Someone on ebay sells a module that allows a bypass from the gm computer, for about $50. It allows the system to retrofit to any car and can be adjusted from zero assist to max. The epas units are cheap.

My only concern is adapting the steering shaft to the FD. I'd be nervous about welding.

You can either weld or cut and use slip joints from someone like Unisteer.

I looked at adapting the EPAS steering column from the Opel Corsa, as it is called in the UK/Europe. This is a GM vehicle/component, the same as Holden Barina (the equivalent model in Australia) and probably the same as certain small/medium GM cars in the US - possibly the Saturn? As noted earlier in this thread, there are aftermarket controllers to make these adjustable.

However, there really is very little room under the dash in any generation RX-7 to fit the EPAS motor. Not saying it can't be done - but it's crowded in there. While the original cars these EPAS units came from were often small, they had taller cabins with more room under the dash.

Also, it would have been virtually impossible for me to comply for street registration in Australia. I have an exceptional suspension/steering fabricator at my disposal and he didn't want to touch an EPAS conversion. It's a race/rally car only option really IMO and even though you'd want it done properly to ensure the column was still collapsible.

I also prefer the EHPS option from a failsafe perspective. Worst thing that can happen is the steering will become heavy if it fails. The EPAS units physically turn the steering column shaft independent of your control.

I dont think that this is true. At least not for any of the standard column units I've seen and used.