Power steering flow control (Jim Shea alert!)
04-05-2007, 11:19 AM
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St. Jude Donor '07
Power steering flow control (Jim Shea alert!)
I've been looking at the threads on flow control from the power steering pump, and I've come up with a 
question.
http://forums.corvetteforum.com/show...ght=droop+pump
I'm going to be running a Hydroboost unit and a Jeep box, and I'd like to make sure it always has full P/S fluid flow. Could the EVO valve be installed between the Hydroboost and the Jeep box to moderate the steering action but keep the Hydroboost happy?
question.
Originally Posted by Jim Shea
The Jeep controller can be used with the EVO valve on the Escalade pump. You don't need the entire Escalade pump you just need to unscrew the EVO valve from the back of the pump. Remove the discharge fitting from your Vette pump. Screw the EVO valve in its place. (This presupposes that you will have clearance behind your pump to fit the EVO valve.) The EVO valve does take up more space.
Just use the truck EVO valve do not use the flow control valve from inside the truck pump. The Corvette flow control valve is set for a maximum pressure relief setting of 1100 psi. Truck pump have pressure relief settings of 1450 psi. The higher truck pressure relief will most likely cause your Vette hoses to leak.
I don't know what type of speed signal the Jeep controller requires.
The Jeep system also had one other input beside vehicle speed. It had a steering wheel rotation sensor. The sensor was part of the steering column. I doesn't have to be fitted on the column it just has to be plugged into the controller box.
I did find this information in my files: The EVO valve was designed for a 250Hz PWM signal, modulated between 5% and 95% to get a 12 volt signal.
You might be able to design a simple on/off circuit that would trigger the EVO valve to minimum flow at 25 mph for instance. This might allow you to get around a controller box.
Just use the truck EVO valve do not use the flow control valve from inside the truck pump. The Corvette flow control valve is set for a maximum pressure relief setting of 1100 psi. Truck pump have pressure relief settings of 1450 psi. The higher truck pressure relief will most likely cause your Vette hoses to leak.
I don't know what type of speed signal the Jeep controller requires.
The Jeep system also had one other input beside vehicle speed. It had a steering wheel rotation sensor. The sensor was part of the steering column. I doesn't have to be fitted on the column it just has to be plugged into the controller box.
I did find this information in my files: The EVO valve was designed for a 250Hz PWM signal, modulated between 5% and 95% to get a 12 volt signal.
You might be able to design a simple on/off circuit that would trigger the EVO valve to minimum flow at 25 mph for instance. This might allow you to get around a controller box.
I'm going to be running a Hydroboost unit and a Jeep box, and I'd like to make sure it always has full P/S fluid flow. Could the EVO valve be installed between the Hydroboost and the Jeep box to moderate the steering action but keep the Hydroboost happy?
04-05-2007, 05:27 PM
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All of the EVO valves that I have seen are designed to screw right into the power steering pump discharge port and replace the original discharge fitting. So I don't know of any way to control the flow after the hydroboost unit.
Jim
Jim
04-05-2007, 07:29 PM
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St. Jude Donor '07
Does the EVO valve have threads that match the old P/S pump outputs? This is something I really want to try...
04-05-2007, 08:29 PM
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St. Jude Donor '05-'07
The Hydroboost unit has a resivoir that will "accumulate" the highest pressure. The EVO valve will not deminish your braking.
Go to:
http://forums.corvetteforum.com/show....php?t=1403161
Go to:
http://forums.corvetteforum.com/show....php?t=1403161
04-05-2007, 09:05 PM
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St. Jude Donor '07
The Hydroboost unit has a resivoir that will "accumulate" the highest pressure. The EVO valve will not deminish your braking.
Go to:
http://forums.corvetteforum.com/show....php?t=1403161
Go to:
http://forums.corvetteforum.com/show....php?t=1403161
Now I just need to know where I can find the Caddy and Jeep parts needed.
04-05-2007, 11:24 PM
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St. Jude Donor '05-'07
You need to read that thread more carefully. The accumulator on a Hydroboost will not loose pressure "after a few pumps". The EVO valve is a variable flow bypass valve.
You need a few other things that you mentioned. You need a VSS, steering position sensor and an understanding of how the system works.
04-06-2007, 08:44 AM
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Speedway motors sells fixed size, valves for the pumps. They require AN hoses though I believe.
You buy a couple, try them out and find the one you like the best
You buy a couple, try them out and find the one you like the best
04-06-2007, 11:39 AM
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St. Jude Donor '07
You need to read that thread more carefully. The accumulator on a Hydroboost will not loose pressure "after a few pumps". The EVO valve is a variable flow bypass valve.
You need a few other things that you mentioned. You need a VSS, steering position sensor and an understanding of how the system works.
You need a few other things that you mentioned. You need a VSS, steering position sensor and an understanding of how the system works.
04-30-2007, 01:44 AM
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St. Jude Donor '07
The Hydroboost unit has a resivoir that will "accumulate" the highest pressure. The EVO valve will not deminish your braking.
Go to:
http://forums.corvetteforum.com/show....php?t=1403161
Go to:
http://forums.corvetteforum.com/show....php?t=1403161
That's an RPM indicator, not a speed indicator. I'm trying to find one that does something similar based on VSS input.
04-30-2007, 08:33 PM
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St. Jude Donor '07
Looking back at that thread, I wonder if a circuit like this: http://www.elecfree.com/electronic/a...eed-indicator/ could be adapted to trip the EVO valve at a given speed.
That's an RPM indicator, not a speed indicator. I'm trying to find one that does something similar based on VSS input.
That's an RPM indicator, not a speed indicator. I'm trying to find one that does something similar based on VSS input.
Last edited by I'm Batman; 04-30-2007 at 08:37 PM.
