Hey guys,

need help

I have miata with a series 6 13bt conversion and wanted to keep the powersteering and A/C... Had to use a S4 or S5 power steering pump due to space limitations... regardless I am running a microtech stand alone ECU so the power steering is always on and very light... the light steering has no feedback... I was wonding if there is a way to hot wire the power steering controller on top of the pump so it senses the car is moving at high speed so it firms up the steering all the time...

before you say remove the belt, and drive without powersteering... not happy with that as its too tight...

please help...

thanks

Greggtr

 

The problem that you're expierencing is more than likely caused by the FC pump flowing fluid at a much higher volume, at more pressure, or both. this will cause an overboost situation in your power steering system, reducing effort and feel.

I work with Hydraulic Power Steering, and there are a few ways to change the feel at a design level. You can give the gear a stiffer torsion bar (it's the only mechanical connection between your input shaft and pinion). The torsion bar actuates the valve. You can also change the boost curve (how much boost with respect to valve angle). Finally, you can change the pressure or flow of the pump to the gear. You can also do a combination of the three. As a part of the public, you can only really change the pump, as you have done, which will either raise the fluid pressure and flow, or you can lower your pressure and flow. What I suspect has happened, because the FC is alot heavier than a Miata, that the FC pump produces a higher pressure and flows more fluid, effectively changing your boost curve and making your efforts very very low. The only way to change this is to figure out a way to mount the proper pump on the motor, or to swap to a mechanical MIATA rack. DO NOT just remove the PS pump, as this is very VERY detrimental to the durability of the steering.

 

I also forgot to say that you could underdrive the FC pump so it flows roughly the same volume at roughly the same pressure as the stock Miata pump.


Also, it is detrimental to the steering gear, which is detrimental to the steering .

 

^ Not to hi-jack a thread, but you seem to be very knowledgable.

What is your opinion of "de-powered racks" in terms of racks that have had the internal valves removed, and the fittings welded shut? (flyingmiata write-up style)

 

very bad idea. read my post in this thread:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fd-power-steering-full-manual-conversion-write-up-631992/page2/

The only thing that I got wrong is that a true manual rack doesn't have a torsion bar, because there is no valve that needs to be actuated. All you have is your input shaft and your pinion.

 

So then is the only source of manual racks stock racks. I generally see people doing this because they couldn't find any place that sold new racks.

*or to have a custom solution done

 

thanks for the replies... but I guess I didn explain fully...

The S4/5 Powersteering unit is machanically connected (belt)
BUT not electrically... there are 6 wires comming our of a plug
from the top of the unit form something that looks like a solinoid, there are hanging loose....

From what I understand whats going on ... the solinoid is controlled by the
ECU which uses the speedo signal.... So when the car is moving slowly the
power steering is very light (like in my car) but when the speeds increase
the solinoid is activated and it firms up the steering... SO my question is which
wires do I have to send an negative voltage and which one to send a positive
voltage to activate the solinoid to always have the PS think that the car is moving
quickly thus firm up?????????????

 

I didn't know that the FC used VAPS (Variable Assist Power Steering). As far as that goes, I have no clue how to wire it up.

 

huh? rephrase your question please.

 

You know... I was thinking about this last night thinking "I bet he either answers that ambiguous question wrong, or can't figure out what I was asking in the first place."

Turns out I was right.

My question is much more simply "Do you know where I can get a new (not used) stock or aftermarket manual rack for the 2nd gen RX7?"

Edit: Heck, I had been so incredibly nub as to ask a question without using a ? anywhere at all. Tsk Tsk. I don't know what I was doing when I made that post.