August 2017

The Pump

There are several possible choices for a pump.  I decided to go with a pump from a Gen 3 MR2 Spyder.  It pulls relatively low current, has well documented conversion wiring diagrams, and has a an integrated reservoir.

The pumps aren't cheap.  A good used pump will run about $300 on eBay.

Mounting location

Under the hood is the obvious choice and is totally doable. I need the weight in the right rear, so I decided to put it in the trunk.  The wiring is easier, but the hose routing is obviously an issue.

Major Parts Needed:

MR2 Gen 3 EHPS pump
Apprpriate gauge power wire depending on your run length
A relay
Fuse or circuit breaker
a switch
A mounting solution for the pump. I modified a bracket from K-Motor Performance.
Standard -AN 6 hose for the low pressure return
-AN6 power steering hose for the supply side
M16x1.5 inverted flare to -AN 6 adapter (Any descent hydraulic shop can make this)
Adapter from your rack to -AN 6 (From a hydraulic shop of Flyin Miata has one)
-AN6 hose ends. Steel for the high pressure side. Aluminum is fine for the return
-AN6 to 3/8" hose barb adapters
The return hose is aver 15" long, you shouldn't need a cooler.

Removing the old steering
Well, what can I say? just unhook everything, drain it and set it aside.
You will have this plus the mounting bracket.

Look at all that open space.

Pump Mount

Map out your pump location and fit up your bracket.  I used a K-Motors mount upside down.  It worked great.  Some grinding and a bit of bending were required to make it perfect.  I would liked to have used nuts and bolts, but install above some blind frame pockets required rivnuts to be used, still super strong.

For the front leg, I used 5/16" all-thread also into a rivnut.

Failure

The Gen 3 pump won't run. I don't have enough time to troubleshoot it.  Very disappointing after all that work. I've got a proven Gen 2 pump on the way.  I'll troubleshoot the Gen 3 pump as a project this winter.

Gen 2 Pump

It requires an external reservoir, but no ECU.  Mounted close to the trunk floor on two 5/16" all-thread uprights. It's surprisingly solid mounted this way.  Wiring and hoses were minor with the previous work. I fabricated a simple bracket for the reservoir and mounted it straight to the pump motor.  Very compact.