jonathan_ed3

iTrader: (1)

What happens to the variable power steering system if I don't have a pressure switch, control unit, and the control valve hooked up electronically?

I didn't realize these cars had the variable assist steering...thought it was only the FC's + until I started separating the wiring diagram.

Can anybody tell me what will (or wont) happen if I unplug the brain and control valve/pressure switch from the variable assist system?

Or, can anybody tell me a way to make it work without having the Mazda pump/pressure switch?

Ark1

I am just about there as I have installed the power box but without the solenoid and control unit and just a straight pump from a Mazda Precida. What is supose to happen is that at low rpm more flow goes to the steering box to assist in steering into parking spots and the like. At highway speeds some of the pressure or flow bypasses the steering box circuit and give lesser assist or more road feel. Since I don't have all the parts I am going to give it a try and if it is too difficult to drve on the highway I will either drop the pressure at the pump or install a restrictor to limit the flow. Of course the draw back will be that at low RPM it will be very difficult to steer the car into parking spots. Time will tell as I have all componets mounted but must convert the steering column and do the Hydralic piping. Have ordered Metric to AN-6 fittings to do the plumbing.

TonyK.

jonathan_ed3

iTrader: (1)

Thanks for the response. I thought I wouldn't get any...

So you have essentially bypassed the control valve all together. That's what i was thinking about doing. I can't make my system work because I don't have the factory speedometer anymore. The Control Unit in the dash receives input from the factory Speedo/VSS and I don't have a way to mimic this input any longer.

It seems to me like removal of/bypassing the control valve at the gear box like you have done would essentially make the system mimic the "full assist" function that the control valve produces, but at all speeds, instead of just low speeds.

To me, this will probably be fine. This is a street car, and I mostly drive in straight lines! If the steering feels like an old Buick, that'll be just fine for me.

however, you mention the car may be too difficult to drive on the highway...is this because you feel the steering may be too twitchy? That could definitely be a problem.

trochoid

iTrader: (6)

I broke the PS electrical connection on the sender on a friends SE. He didn't notice any difference in the steering. You should have no problems as the difference isn't that great.

Ark1

I have installed all new bushings on the entire car and the idler arm as well. As long as the front end is tight all should be okay. However should the system be a bit loose at highway speeds because of the amount of assist available over correcting may be an issue. ( Twitchiness) Will see.

Just to let you know I wanted to take the old box out and I split it in the car. The column from the box with the ball screw left on the column. I dropped the bottom bearing race and lost it, no stock in Canada, so I had to look for a replacement of some type. Hence why I am going the power box route. I am still waiting on parts to do the adaptation, so it looks like a couple of weeks before I can get this thing going. It is winter here and I don't have the car on the road so it will be spring before a road test will be done.

TonyK.

Ark1

All my parts have come in and I have spent the last week of spare time adapting and installing what I have ordered.

The pump is from a 95 Mazda Preceida with remote resivor. It came with a serpentine pulley so I ordered a V belt pully from Car Quest bored out the diameter and cut a blind KeyWay on the shaft. I also installed a set screw to make sure the Pulley doesn't walk off the shaft. To get around the water pump an Idler was also purchased from Car Quest. The Steering box was found on ebay and came in from Georgia. AN-6 Adapters 9/16 x 18 and 5/8 x 18 ( this works out to 14MM x 1.5 and 16MM x 1.5) from Tallon Hydralics in Florida. Since the Precida uses a banjo bolt I cut off the hose end and bored out an AN-6 straight male fitting to 3/8" NPT and silver soldered it to the 10MM steel tube. Hydralic hoses were crimped up at a local jobber and the straight hose fitting to the pump was a reusable fitting that allowed me to cut the high pressure hose to length and make up the hose at home.

The steering box uses a 5/8" x 36 spline so I purchased a Steering Ujoint from the Chasiss Shop and then cut the stock column to suit. In order to make the colapsable column still work a sleeve was installed on the outside of the Mazda column and Acetel bushing were turned on my lathe to fit the column diameter. The OD of the sleeve just fits through the firewall and will be siliconed in place to make a water tight seal.

The system uses just over a US Quart of fluid to fill the lines and cooler mounted in front of the car. So far no leaks, the pump is quiet and I will be tightening up all the ball joints and mounting bolts to complete the installation.

I still may look for a rack as I have been reading up on the sizing of racks for power steering conversions and the ill effects of Bump Steer. The stumbling block currently is finding a copy of TRW Federal Mogal's X 4000 cataloge. So for now the pump, cooler and resivoir tank effort have not gone to waste.

TonyK.

rotaryB-2000

nice