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-   3rd Generation Specific (1993-2002) (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/)
-   -   EPS (electronic power steering) conversion for FD (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/eps-electronic-power-steering-conversion-fd-991025/)

rotorooter93fd 03-26-12 12:06 AM

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.

BLUE TII 03-26-12 03:22 AM

1 Attachment(s)
http://www.mazdaspeedy.com/2011/11/t...-steering.html

MRS pump, controller and reservoir in one small package.

Attachment 718370

gracer7-rx7 03-26-12 11:17 AM

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. :)

BLUE TII 03-26-12 12:15 PM

Hmmn, I hate the numb FD power steering feel.

I really like the feel of my Mazda3 power steering.

munroman 08-30-12 01:16 AM

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

mikey13b 12-02-18 10:47 PM

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

cr-rex 12-03-18 01:34 AM

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

billyboy 12-03-18 01:36 AM

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.

cr-rex 12-03-18 10:41 AM

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.

DaleClark 12-03-18 11:05 AM

^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

BLUE TII 12-03-18 12:55 PM

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.

billyboy 12-03-18 01:09 PM

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.

cr-rex 12-03-18 01:29 PM


Originally Posted by DaleClark (Post 12317050)
^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

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.

dguy 12-03-18 03:52 PM

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

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

It works well,

KYPREO 12-03-18 05:45 PM

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).

mikey13b 12-04-18 04:01 PM


Originally Posted by KYPREO (Post 12317128)
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?

KYPREO 12-04-18 05:00 PM


Originally Posted by mikey13b (Post 12317308)
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.

mikey13b 12-04-18 07:24 PM

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

KYPREO 12-04-18 08:47 PM


Originally Posted by mikey13b (Post 12317333)
Awesome thanks heaps!
Is yours going into an FC or FD?

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

mikey13b 12-04-18 09:32 PM

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

KYPREO 12-04-18 11:17 PM


Originally Posted by mikey13b (Post 12317349)
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.

BlackEuropa 12-05-18 12:48 AM

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.

dguy 12-05-18 11:25 AM


Originally Posted by BlackEuropa (Post 12317373)
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.

KYPREO 12-05-18 04:01 PM


Originally Posted by BlackEuropa (Post 12317373)
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.

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.

dguy 12-05-18 06:13 PM


Originally Posted by KYPREO (Post 12317495)
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.


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