MR2 Electric P/S Pump Swap??

[spf_lexus]

I have a friend at school with a 94' silvia swapped with a nissan VH45 V8 and he has been showing me his MR2 electric pump swap. He had to relocate his stock pump due to clearance issues but it got me thinking. If i can relocate my P/S pump, I can delete the pump altogether and then i can play around with a second FISH bracket for the potentioal of twin centrifugal blowers! On top of that, slight increase in MPG and unlock a couple BHP.

The pump is 12v, and pulls 60amps at full load. the unit is controlled w/ a basic 12v feed but is controlled with a 4-wire connector using pulse width modulation from the ECU.

here's what i want to know....



Can I utilize my SC400's stock steering rack sensor to trigger the pump? I know the stock P/S module has a function that varies sensitivity based on vehicle speed and i know the MR2 pump uses a variable signal based on vehicle speed as well.

 

[spf_lexus]

I know that 60 amps is 60% of the stock alternator output and if I include my ignition drain from the supercharger, both of my Kenwood KAC amps and batt. relocation... I am about to max it out. Fortunately I already have a 140amp Lextreme alternator, Optima redtop, 4 gauge upgraded alternator lines and grounds so i should be able to deal with it.


If anyone knows if the stock P/S module runs any sort PWM function, I think I can wire this up. Frankly my P/S module isnt used ATM so i dont care if i cut the harness up.


Any help is appreciated,

Sean

 

[ihiryu]

Sorry I can't help you, but I just wanted to say it was weird because I was looking at this just yesterday thinking about installing an MR2 P/S pump in my next car ha ha.

 

[spf_lexus]

Cool, at least i have someone on the same page hehe. I spent 2 hours last night looking up sucessful conversions and 90% of them just run a 75amp relay and run the pump off a switch. At first I wanted the factory "progressive-ramp" but it looks like it may be a bit much to hook up. I also discovered that the pump has 3 outputs... Low, high and off so if the constant 60amp drain is a problem, I could potentially wire it up to the "Low" setting and maybe knock that down to 40amps or so? My stock rack/lines are old and I can feel the lack of resistance versus a stock, clean system so I really dont mind if the pump puts out a little less PSI. At freeway speeds I love not having a "touchy" p/s... more direct feel to the road.

 

[sideshow]

the mr2 p steer works of another ecu
the psteer ecu also talks to the engine ecu for the mr2
so since your not running the mr2 engine ecu u might have to trick the
psteer ecu

i have looked at using an electric pump from an opel and give it a pulse to control the
amount of assitance it gives but u need to get the right model as there are 2 types
i have been asked abou tthis for race cars

but some race cars here are starting to use a new setup
i have heard some very very late suzukis run a small motor which runs on the
steering column and it recognises whent he steering it turned and assists that way
its just a small motor with rubber wheel i guess and its connected to the steering column
i havnt actually seen this setup just been told about it thru guys who go racing
so there is no actual hydraulic parts

 

[ihiryu]

that's pretty crazy, but I'm sure those parts wouldn't be available here in the states.

Also SPF, I know the earlier years of the SW20 had a high, Low, and off position.

Another thing too, the newer MR-S' have their resvior (spelling?) built into them. Just something to think about

 

[spf_lexus]

Also SPF, I know the earlier years of the SW20 had a high, Low, and off position.

Another thing too, the newer MR-S' have their resvior (spelling?) built into them. Just something to think about

Thats good to know. I was assuming I would re-use my reservoir but that takes another component out of the equation. The more I think about it the more I think I might just run it 12v constant on low. thats way I can cut down on the draw and wont have to deal with super sensitive steering at high speed. I dont mind fighting the wheel "a bit" but just dont want to deal with getting a pulled muscle from parking my car heh.

i have heard some very very late suzukis run a small motor which runs on the
steering column and it recognises whent he steering it turned and assists that way
its just a small motor with rubber wheel i guess and its connected to the steering column
i havnt actually seen this setup just been told about it thru guys who go racing
so there is no actual hydraulic parts

I'll have to look into that, sounds like a nice concept if I can source a late model.

 

[RedPhoenix]

I will be running 12v on a window switch. basically anything over a certain speed or RPM will turn off the pump or have it run slower, havent really decided yet... But I am using an MR2 pump.

 

[1uz747]

I've got the MR-S electric pump. It's a pretty good unit with the reservior and also the control module built in. I should be able to wire it up to use the speed pulse signal from the gearbox to control the pump speed.

 

[spf_lexus]

I've got the MR-S electric pump.

What do you think of it feel wise versus stock? Last issue I can forsee is finding a differently oriented belt tensioner so I can cleanly delete the stock P/S pulley.