Jump to content
SAU Community

Power Steering Rack Solenoid

Chris Wilson
 Share

Recommended Posts

Chris Wilson Proficient

Chris Wilson

Posted
Posted

How is the steering rack ("weight, effort, pressure", call it what you will...), solenoid triggered? Is it either open or closed, thus light or heavy, or does the ecu duty cycle it to give a linear steering effort change? Thanks.

Link to comment
https://www.sau.com.au/forums/topic/298883-power-steering-rack-solenoid/
Share on other sites
Chris Wilson Proficient

Chris Wilson

Posted
  • Author
Posted
What type of car?

Most car the sensor on the rack is only a sensor for the ecu so it knows to bump the idle up so as the motor dosnt stall from the load of the power steering pump

Interested in both R33 GTS-t and R33 GTR

The idle up is via a pressure switch in the pump high pressure line. The rack itself has a bypass bleed solenoid to vary rack assistance effort.

lawler Community Regular

lawler

Posted
Posted
Interested in both R33 GTS-t and R33 GTR

The idle up is via a pressure switch in the pump high pressure line. The rack itself has a bypass bleed solenoid to vary rack assistance effort.

Ah yeah I know what you are talking about now.

It should be liniar. the ecu (or might be another modul) ajusted the efford compared to the speed the car is doing. E.g. more asisted at low speeds in car parks and less assisted at hight speed on the highway

psi Experienced

psi

Posted
Posted

I am pretty sure the hi-cas ecu in the boot controlls the unit, I am also interested in how it is operated.

My 33 gtst sometimes goes heavy and stays heavy. then next time i start it, it could be normal again.

Im looking at modding it.. possably removing it, would love to know how it is operated!

85URK Grand Master

85URK

Posted
Posted

i am having a problems with my steering aswell feels like its controlled electronically when driving and makes the car viere from left to right slightly, so i could be driving down a straight bit of road and the car will just turn itself to one side slightly and start heading that way then turn back all of a sudden, its freaking annoying.

do u think replacing the hicas ecu will fix this problem?

as the hicas was also playing up, and was wiggling the arse end intermittently, so i removed it. maybe they are all related, and the hicas ecu is responsible.

heller44 Mentor

heller44

Posted
Posted

found the info I was looking for.. in this thread.. http://www.skylinesaustralia.com/forums/Po...amp;hl=steering

look for the waveforms on post #29..

I haven't gotten any further into replacing the hicas module as mine is working.. after I fixed everything else.

  • 3 years later...
kitto Mentor

kitto

Posted
Posted

Major thread revival.

So i'm trying to find out what signal the Hicas unit gives the power steering solenoid in an R33 rack.

As the rack isn't actually in an R33 i can't just hook up a scope to the plug and see what its doing.

I need to know the duty cycle and frequency of the output is at say 0km/h and 100km/h. I assume it will be a linear line between those two points, above someone said its a square wave, thats a start.

The above link from heller44 does not work.

I looked in the R33 workshop manual which was no real help. It just stated that you should see approx 6-8V at 0km/h and around 2V? at 100km/h.

No actual duty cycle or frequency data is given in the manual.

What i'm trying to hopefully do is control the solenoid from my Link ECU in my R31. I previously have driven the car with the solenoid completely off and it did feel heavy at a stand still and low speeds.

Any help would be appreciated.

  • Like 1
kitto Mentor

kitto

Posted
Posted

Sweet, cheers for that mate.

That should be pretty easy to work out the duty cycle from then.

Locked at 123Hz across the board.

At 0km/h if the Solenoid is meant to be getting Approx 4.4 - 6.6V that is a rough 32 - 47% Duty cycle

At 100km/h if the Solenoid is meant to be getting Approx 1.5 - 2.2V that is a rough 11 - 16% Duty cycle.

Calculated on the basis of 14V.

After 100km/h do you know if the duty drops off to 0 eventually or it stays at approx 16% after 100km/h?

Looks like its just a case of doing a linear graph every 10km/h from 0 to 100 using those duty cycle's as the start and finish points.

  • Like 1
  • 6 years later...
nicostar Explorer

nicostar

Posted
Posted (edited)
On 3/19/2013 at 3:07 AM, kitto said:

Sweet, cheers for that mate.

That should be pretty easy to work out the duty cycle from then.

Locked at 123Hz across the board.

At 0km/h if the Solenoid is meant to be getting Approx 4.4 - 6.6V that is a rough 32 - 47% Duty cycle

At 100km/h if the Solenoid is meant to be getting Approx 1.5 - 2.2V that is a rough 11 - 16% Duty cycle.

Calculated on the basis of 14V.

After 100km/h do you know if the duty drops off to 0 eventually or it stays at approx 16% after 100km/h?

Looks like its just a case of doing a linear graph every 10km/h from 0 to 100 using those duty cycle's as the start and finish points.

Sorry to revive an old thread mate, wanted to know if there is a way to achieve this with some kind of dc converter? I got one of these racks with the solenoid in it but my r33 didn't have the solenoid type rack or wiring for it to begin with.

Edited by nicostar
GTSBoy Grand Master

GTSBoy

Posted
Posted

What do you mean "DC converter"?

If you just want a fixed voltage at the rack, you could just blow away the extra volts with a suitably sized (ohms and watts) resistor.

If you wanted to go to the effort of using more electronics to achieve the same goal and waste a little less electricity, you could certainly put a DC-DC converter on there.

Or, you could build an Arduino to run a PWM output to an SSR. Choose a suitable frequency for the PWM (maybe 100Hz) and just punch out the pulsewidths required to get the voltage you want. It's pretty clear that it wants somewhere around 6V to get max assist (at low speeds) and ~2V to get minimum assist at higher speeds. If you went to a little more effort you could connect an Arduino input to the VSS and give it full variable assist to the same extent that the HICAS CU would.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • PranK
      New Skyline will be RWD and manual

      By PranK · Posted

    • GTSBoy
      Nismo GT Pro LSD configurations

      By GTSBoy · Posted

      No, you're wrong, and you've always been wrong about this. The Nismo has 2 sets of openings. One is a real 2-way, and the other is a 1-way. There is no 1.5-way possible with the ramps that they offer. A real 1.5-way does exist. That Cusco stuff I posted is a prime example. If the forward drive ramps are, say 55°, and the overrun ramps are, say, 30°, then you will get about half as much LSD effect on overrun than you do on drive. It is real, it realy works. OK, you're slightly right. The Nismo has 55° and 45° ramps on the 2-way, so it does offer less LSD effect on overrun. But, I think that just means that they've (probably) sensibly established that you do not want actually equal LSD effect on overrun. You just want "quite a lot, but not quite as much as the drive LSD effect".
    • DraftySquash
      Newbie from VIC

      By DraftySquash · Posted

      Just wanted to unearth this and post my baby with the new front ❤️😝 Took her to my wedding rehearsal today. Next up is getting wide skirts (after wedding)
    • Kinkstaah
      Nismo GT Pro LSD configurations

      By Kinkstaah · Posted

      Yea, that is what I was getting at in my ramblings too. The nismo one actually is a 1.5 way and a 1 way. They don't do a *2* way because a true *2* way would have equal ramp angles. Or is that a true 1.5 way? Realistically I think a "1.5 way" does not actually exist. A diff can either lock in two directions or one. It also doesn't help that a LOT of people in Australia speak about 1.5 way diffs are referring to their 1 way diff.
    • GTSBoy
      Nismo GT Pro LSD configurations

      By GTSBoy · Posted

      Well, the trouble with that ^^ is: The configuration shown is absolutely a 1-way, not a 1.5-way. There is no way that a 1.5-way can be said to offer LSD action only on acceleration. If Nismo cannot get that right, then it is impossible to believe their documentation. That ^ is not a 1.5 way setup. That is a 1-way.   And so now I have allowed all doubts to flourish and have gone back to look at the MotoIQ video. I originally made the mistake of believing him when he said "this is a 1.5-way" at the ~6:10 mark. Because what he did was take the gear assembly out of the 2-way opening and just rotate it one place to the left to drop it into the 1-way opening. When he dropped it in there, the cam was "backwards" compared to the correct orientation shown in all other photos of that config. The flat shold have been facing the 1° ramp side of the opening, not the 55° ramp side. And I thought, "gee that's cute", but I was concerned at the time, when he put the other ring back on, that the gap between the rings looked like it was wider then in the 2-way config. And then I said a lot of things in my long post on Tuesday that could only make sense if the guy from MotoIQ was correct about what he'd done. BUT... I have now done my homework. I grabbed a frame of the video with the 2-way config, and then grabbed another with the "1.5-way" config, snipped out the cam and opening of that frame and just pasted it direct on top of the 2-way config. I scaled it so that the triangular opening was almost exactly the same height in both. AND.... the gap between the plates is wider with the cam installed in the triangualr opening backwards. That is.... it cannot go together that way. There would be massive force on the plates all the time, if you could even reassemble it.  So, My statement on the matter? The Nismo diff is actually only a 2-way and 1-way. There is no 1.5-way option in it, regardless of what they say. Here's a photo of a real 1.5-way ramp opening from Cusco (along with the 1 way option). And the full set of 1 through 2 way options from their racing diff, which is not same-same as what we'd typically be using, but...the cams work the same. A little blurry, but it comes from this Cusco doc, which is quite helpful. AND.... Cusco do in fact do what I suggested would be sensible, which is to have rings that do 1 and 1.5, and 1.5 and 2. Separately.  
×
×
  • Create New...