What about an EVO valve?
Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.
Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.
Cool, the PDF explain between which speeds to interpolate.
From what I could read here and there, EVO take a PWN signal to modulate and I know at some point I'll have a dedicated microcontroller to deal with those kind of things.
Anyone know from which car I you could pick a EVO valve that would fit the Corvette ps pump?
Below is a picture of the EVO valve (w/ Standard valve on top).
What car are they from? I see them on pumps from mid 90's GM products like Olds Acheva, Grand AM etc. Some Saturns.
Also, as far as hydroboost, the EVO valve wouldn't have any effect on that.
Here is the catch with the EVO controller. You don't want to reduce pump pressure, at speed, while turning the steering wheel quickly. You will get what is called pump "catch up" where the wheel feels like it hits a stop. All of these systems use a steering wheel rotation sensor to detect that. Thats why I thought a 2-axis acelerometer would be the best choice for the controller.
I have a ton of information on this if you would like to pursue this. I talked to a retired Ford engineer about this and a Delphi steering engineer. They gave me lots of info.