From: Alex Karahalios
Date: March 15, 2003 11:27:26 AM MST
To: uselectricar_ev@yahoogroups.com
Subject: [uselectricar_ev] Power Steering Pump
Reply-To: uselectricar_ev@yahoogroups.com

I lifted my Prizm up last night and had a good look at the power
steering pump. I wrote down the numbers and then checked this morning
with Toyota. The number on the “pump” is actually the pump motor number
and is 80960-17011. This is the power steering pump motor for an MR2 –
model years 1990-1995. A replacement motor from Toyota is special older
and costs $1000. The pump model part number is 44310-17011. The pump
costs $378.

I guess anyone looking at replacing them would be better off looking at
used parts. While doing various searches with Google I also found some
documentation on the MR2 steering pump. The pump motor is actually
rated at 10V. The MR2 has an ECU and motor controller which varies the
motor speed depending on speed.

The MR2 pumps docs say that the voltage at 0mph should be between
9V-11V. At 40mph it should be 3V-5V.

It looks like the Prizm pump is powered by 12V. I guess the first thing
would be to try to reduce the voltage to 10V to reduce the noise the
pump makes. Maybe a small Curtis DC motor controller could be used to
vary the pump speed depending on vehicle speed. Or I guess the original
MR2 ECU and motor controller could be used, although it has too many
MR2 specific inputs.

My main motivation for looking at this is to reduce the pump noise.
Making the pump variable depending on speed would also help in reducing
the current draw.

Alex Karahalios

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From: “Christopher Zach”
Date: March 15, 2003 3:06:18 PM MST
To:
Subject: Re: [uselectricar_ev] Power Steering Pump
Reply-To: uselectricar_ev@yahoogroups.com

The reduction in voltage is probably to allow the pump to cut out
once the
car is moving, giving it a “sports car” sort of feel.

My pump makes almost no noise at 12 volts. Check the wrecking yards;
a lot
of MR2s were sold to teenagers…

Chris

—– Original Message —–
From: “Alex Karahalios”
To:
Sent: Saturday, March 15, 2003 1:27 PM
Subject: [uselectricar_ev] Power Steering Pump

> I lifted my Prizm up last night and had a good look at the power
> steering pump. I wrote down the numbers and then checked this morning
> with Toyota. The number on the “pump” is actually the pump motor
> number
> and is 80960-17011. This is the power steering pump motor for an MR2 –
> model years 1990-1995. A replacement motor from Toyota is special
> older
> and costs $1000. The pump model part number is 44310-17011. The pump
> costs $378.
>
> I guess anyone looking at replacing them would be better off
> looking at
> used parts. While doing various searches with Google I also found some
> documentation on the MR2 steering pump. The pump motor is actually
> rated at 10V. The MR2 has an ECU and motor controller which varies the
> motor speed depending on speed.
>
> The MR2 pumps docs say that the voltage at 0mph should be between
> 9V-11V. At 40mph it should be 3V-5V.
>
> It looks like the Prizm pump is powered by 12V. I guess the first
> thing
> would be to try to reduce the voltage to 10V to reduce the noise the
> pump makes. Maybe a small Curtis DC motor controller could be used to
> vary the pump speed depending on vehicle speed. Or I guess the
> original
> MR2 ECU and motor controller could be used, although it has too many
> MR2 specific inputs.
>
> My main motivation for looking at this is to reduce the pump noise.
> Making the pump variable depending on speed would also help in
> reducing
> the current draw.
>
> Alex Karahalios
>

From: Andy Berkun
Date: March 15, 2003 3:10:16 PM MST
To: uselectricar_ev@yahoogroups.com
Subject: Re: [uselectricar_ev] Power Steering Pump
Reply-To: uselectricar_ev@yahoogroups.com

I’m going to try a circuit to sense the load on the pump by sensing the
back EMF of the motor and adjusting the voltage accordingly. It would
connect to the car with just 3 leads if it works. We will try it on ours
first then I’ll publish the circuit.

At 05:06 PM 3/15/2003 -0500, you wrote:
> The reduction in voltage is probably to allow the pump to cut out
> once the
> car is moving, giving it a “sports car” sort of feel.
>
> My pump makes almost no noise at 12 volts. Check the wrecking
> yards; a lot
> of MR2s were sold to teenagers…
>
> Chris
>
> —– Original Message —–
> From: “Alex Karahalios”
> To:
> Sent: Saturday, March 15, 2003 1:27 PM
> Subject: [uselectricar_ev] Power Steering Pump
>
>
>> I lifted my Prizm up last night and had a good look at the power
>> steering pump. I wrote down the numbers and then checked this morning
>> with Toyota. The number on the “pump” is actually the pump motor
>> number
>> and is 80960-17011. This is the power steering pump motor for an
>> MR2 –
>> model years 1990-1995. A replacement motor from Toyota is special
>> older
>> and costs $1000. The pump model part number is 44310-17011. The pump
>> costs $378.
>>
>> I guess anyone looking at replacing them would be better off
>> looking at
>> used parts. While doing various searches with Google I also found
>> some
>> documentation on the MR2 steering pump. The pump motor is actually
>> rated at 10V. The MR2 has an ECU and motor controller which varies
>> the
>> motor speed depending on speed.
>>
>> The MR2 pumps docs say that the voltage at 0mph should be between
>> 9V-11V. At 40mph it should be 3V-5V.
>>
>> It looks like the Prizm pump is powered by 12V. I guess the first
>> thing
>> would be to try to reduce the voltage to 10V to reduce the noise the
>> pump makes. Maybe a small Curtis DC motor controller could be used to
>> vary the pump speed depending on vehicle speed. Or I guess the
>> original
>> MR2 ECU and motor controller could be used, although it has too many
>> MR2 specific inputs.
>>
>> My main motivation for looking at this is to reduce the pump noise.
>> Making the pump variable depending on speed would also help in
>> reducing
>> the current draw.
>>
>> Alex Karahalios
>>

From: Alex Karahalios
Date: March 15, 2003 4:04:45 PM MST
To: uselectricar_ev@yahoogroups.com
Subject: Re: [uselectricar_ev] Power Steering Pump
Reply-To: uselectricar_ev@yahoogroups.com

Hi Andy,

Thanks for the info. Actually, I have some 24V Curtis controllers from
EV warrior bikes that should work OK.

Alex

On Saturday, March 15, 2003, at 12:57 PM, Andy Berkun wrote:

> I think what you are looking for is a controller from one of the
> electric
> scooters to control that pump. Just wire it in as is and set the
> trigger
> control where you are comfortable driving it (so long as the motor is
> running you will have power steering although maybe too slow for your
> habits). The car is quite driveable without power steering at all so
> slowing the pump down is probably a good idea. www.vaporgear.com
> sells the
> controller from their 24 volt scooter but I bet it will run at 12
> volts. The controller cant be over $50. Alternately you can make a
> resistive regulator but its a lot of heat to dissipate. I can send
> you a
> circuit if you want to try this approach.