Friday, April 8, 2011

Electric Power Steering Pump Install

One of the unique features of Hasport's 88 CRX is the wide front end and 255 wide front tires. When we pioneered the idea of using the much wider front tires we knew there would be a trade off in steering effort. Originally we were going use the K-series PS pump with the 88-91 Civic PS rack, but because of the supercharger the PS pump and pulley were going to stick out of the hood a little too much and ruin the look. I know what you're thinking, "There's already a supercharger sticking out of the hood, ruin what look?!?" Well, it just didn't look right.


So after some discussion we decided EPS (electric power steering) would be the cleaner option. This was a couple of years ago and after numerous lame reasons for postponing, I am finally getting around to doing the install. I wish now I had of done it earlier. About the time we had originally planned to do the install Karcepts came out with an installation kit for the second gen Toyota MR2 EPS pump and an article appeared in Honda Tuning. After that prices for the MR2 EPS pump jumped from $50-75 to $200. I'm partially to blame, I suggested the article to Tim Kelly who wrote it for Honda Tuning, but talk about shooting yourself in the foot. Crap, I hate unintended consequences.


So here's the nitty-gritty tech on how the PS pump was done. 


The first thing was finding a reasonably priced PS pump. Setting up alerts on Ebay resulted in finding a $90 "Buy It Now" PS pump from a US salvage yard. It was immediately purchased and then followed up with a quick phone call to the salvage yard to make sure no one snaked it away with a phone call of their own. After the pump was secured a quick trip was made to Hasport's salvage yard to grab some other parts.
Here's what I had after the pump arrived. Steering rack and crossmember from a 1990 Civic Wagovan. BTW all 88-91 PS racks and crossmembers are the same, so there is no one unit that is more desirable. The MR2 PS pump and a Civic manual to see where the return lines need to go. Also in the pic are some heavy duty plugs from a 2000 Prelude SH wiring harness to connect the PS pump, but I decided not to use those.


Mounting the Pump


Having done this conversion once before on Tage Evanson's Time Attack EG I already had a bracket design I kinda liked. I made a couple of alterations to ease installation then cut and bent the bracket.




Two were made, just in case of I needed to make some bending changes, and good thing too. After a two small changes the second bracket fit perfectly.



The engine bay of the CRX is cramped, so I decided to mount the pump on the frame rail just in front of the right front tire.




Originally I had planned to bolt the bracket directly to the frame rail, but the frame rail isn't very flat. So I trimmed the spare bracket and welded it to the frame rail to provide a flat surface to bolt the PS pump and bracket to. I will probably make a lighter weight version of this in the near future once I decide if this is where the PS pump will stay. It seems a little overkill.




Plumbing the System


Before mounting the rack some modifications were made to the PS lines. The PS lines were heading off towards the driver's side of the car and the new pump was going to be on the passenger's side. First the high-pressure line was re bent using a tubing bender so the line came across the back of the cross member and forward making sure it cleared the K-series rear bracket. Next the rubber part of the hose was chopped off.


Next the return lines were shortened. This makes the routing easier since flexible rubber hoses can be used.

The subframe was installed so the hose lengths could be measured.  We found a fitting on a Prelude rack that worked with the MR2 pump and used a piece of fuel hose to mock-up the high-pressure PS hose and figure out the length and how everything is clocked. Next the mock-up was dropped off at the local hose builder. The next day we picked up the new high-pressure hose and some lengths of hydraulic safe rubber hoses. Oh, and a stopped by the salvage yard to grab a PS reservoir and bracket from an EG.




The PS reservoir bracket was modified,




the reservoir installed,



and plumbing was plumbed.









Next, the Electrical part of EPS (to be continued)