Plans for an all electrical setup (power steering too)

Figured Id share it here (although power steering is included as well)

I was reviewing the bmw setup and all the stuff that had to go into it to get it running, and It seemed like I was introducing a lot of things to fail miserably as soon as the motor started (I was imagining a power steering fountain the first time I fired her up )

So after some research I found a good alternative for the power steering pump. The toyota MR2 uses an electric PS system with a pump, At first I was looking at the easier to find MKI system. Unfortunately it requires two computers, a bunch of wiring, and a steering wheel sensor. The MKII power steering pump (featured in 01-05 spyder models):


dunno what the thread sizes are but its easy enough to get fittings for it (I may already have them anyhow)

The advantage is that this pump only requires power and a VSS signal (it senses load or something like that). The Vss signal slows down the pump at higher speeds to reduce oversteer, this may not be an issue since the porsche rack is fine with getting pressure at all times. The only place to really find these pumps is late model salvage, if anybody knows of some forums I can get one at Id be very interested (they are around 250 at late model places, and electric car dudes are snatching these things up). here is the wiring:



this is where I got all the info on it: K20a forum

Only real issue is where to put the pump? Im not exactly sure how huge it is... Ill find space.

Now that steering is out of the way, I have to figure out how to get the brakes boosted. I was told that some 911s use an electric hydroboost system. In fact the carrera 4 of the 90s has exactly what I am looking for. All it needs is a hydraulic pump, accumulator, and the booster unit.
Here is a picture of all the stuff:

(the unchopped image is Here)

The pump (bottom of pic) uses brake fluid to charge the accumulator (next to 12) which boosts the brakes... simple! there is a pressure sensor in the pump that flips the assembly on (no computers )

I found the booster from an e-bay store also selling the master cylinder, the price is resonable (this stuff can be 500 dollars for each component, im looking at about 200 for each)

the whole system uses brake fluid, so it requires a massive brake fluid reservoir:

I asked the same store about the res. they wanted a pretty large sum for it, however, If it comes with the tubes then its worth it (the oem places want like 111 bucks for some tubes, wtf!)
I was thinking of just putting a 2 liter bottle of mountain dew filled with brake fluid under the hood... but I guess ill keep searching for a proper container...

the MC might be a slightly larger bore, Ill have to research the part number when I get the stuff in, but overall I think the setup will work really well with the lexus/951 setup I have in place.

The electricals will consist of a few high amp relays connected to the ignition line, its also suggested that you put one of those temporary fuses on the power steering pump in case stuff goes wrong. Aside from that wiring is simple, just a few high amp relays on the ignition line.. or on switches, whatever works!

Nice idea. I thought the early MR2 pumps were simple DC motors......You of all people should have no issues with wiring it up

The newer Mazda 3 has EHPS. http://www.bba-reman.com/content.aspx?content=Mazda_3_Power_Steering_Pump

Click Me

haha yeah that was my thought " eff... I have to do power steering lines.... im better at electricals"

the early MR2 pumps need a ton of wiring voodoo since the computers need to decide when you need power steering the most, plus they need that wheel sensor (which annoys me) too many expensive computers!

I cant tell with that new mazda 3 thing, is that just a simple motor? The new MR2 stuff is this one unit with the computer and the reservoir attached, I really like it... but its bigger.

.. then again the rack doesn't really care about pressure, a simple dc motor setup could work fine..


another thought is something that tacks onto the column to boost power steering, one of those fully electric jobbies, but i doubt there is room for that, it also needs a wheel sensor
I feel that replacing the power steering rack would kill the porscheness of the vehicle, so the fully electric rack setups might not be ideal (I could be convinced otherwise at this point, car still has no steering at all ) it just bugs me that it would need a separate wheel sensor when its connected to the friggen column anyway, sense it yourself you stupid part.

I don't think that any of those DC motor set-ups are suitable for continous duty.....I would go with manual steering and one of those pumps just for the brakes. Set the pump up with an accumulator and a pressure switch which maintains a set value.....??

yeah thats exactly what this system does, I found some 964 manuals ill chop out some schematics for the brakes. Im also crossing my fingers with an auction for the pump.

the MR2 pump should be capable of "continuous" operation, from what ive read (...somewhere... cant cite it cause it was during a frenzied research session) the computer senses load and turns the pump on/off or just throttles it.
I figure i can play with it once I get it.. . the power sterring pump will likley follow brakes since everything is now independent.

OK, just got the master cylinder (with booster) the pump and reservoir (~600) Just have to get that accumulator and ill be ready to buy NAPA out of assorted metric hard lines! weew!

there is a jaguar system with an integrated accumulator, looks remarkably similar to the porsche system.... its from JAGUAR XJ6 XJ40 FOR 89 -94 MODELS... like 50 bucks on ebay.
I gueeess... the porsche system has the better pressure sensor, which can support a brake pressure warning light..... maybe worth the extra cash I spent.

even more egg on my face, land rover also used a very similar setup, only like the jaguars the pump is attached to the accumulator... and it seems to use the 5 pin sensor porsche uses... and its about a sixth the cost.... FML.

Is this the one?

http://cgi.ebay.ca/RANGE-ROVER-4-0-4-6-ABS-BRAKE-PUMP-95-96-97-98-99-02_W0QQitemZ370216266587QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item56329beb5b&_trksid=p3286.c0.m14&_trkparms=65%3A12%7C66%3A2%7C39%3A1%7C72%3A1215%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

hmmm no, here are the ones I was looking at:

Here (Jag):
http://cgi.ebay.com/JAGUAR-XJ6-XJ40-BRAKE-PUMP-ACCUMULATOR_W0QQitemZ270413282906QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item3ef5e33e5a&_trksid=p3286.m63.l1177&_trkparms=240%3A1318|301%3A1|293%3A1|294%3A50

and Here (rover):
http://cgi.ebay.com/ebaymotors/1996-2002-Range-Rover-ABS-pump-and-Accumulator-Wabco_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1205Q7c240Q3a1309Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem25553b3e18QQitemZ160343735832QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

you can see the rover has a green pressure sensor and it seems to be the 5 pin version, which is eerily similar to the porsche setup (sans the accumulator)
though seeing that price does make me feel a bit better

All the parts are collected except for the accumulator, going to have to dig around for one of those.

The 964 reservoir is awkward, and does not fit anywhere at all... Ive tried to find any place higher than the MC and booster but there really aren't any options.. SO its time to fab up a solution

you guys know what kinds of plastics will work for brake fluid? I am going for a basin kind of looking thing in the drivers side rain tray, with any luck I can use the filler cap from the other reservoir.

the whole setup is shorter and smaller than the 944 MC and hydroboost, I was in nice shirts for the whole holiday weekend so I didnt get down in the foot well to undo the bmw stuff, when I do ill post up some pics, its a nice little setup.

As far as power steering goes, I am really starting to consider just swapping in a manual rack and being done with it for now.