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

    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      In a few years from now, you'll regret that. It'll eat away at you, knowing the truth of the ugly hiding beneath the beautiful exterior... 😛
    • joshuaho96
      R32 GTR - Where to begin

      By joshuaho96 · Posted

      I don't think the G2 profile is particularly dangerous for the engine per se, more just are you actually ok with the turbo lag trade-offs? If the answer is yes then go for it. I personally don't think I'd be ok with it because I spend so much time at lower RPMs and I really enjoy the feeling of being able to stay in 5th gear on the highway and just roll into the throttle to get boost. Or staying in 3rd gear on "gentle canyon cruises" without feeling the turbo lag too badly. The 525 pump should be able to run flat out on factory lines but I would bet the pressure drop from pump to regulator is quite impressive. I don't know how much it would be exactly but I've seen figures like 30 psi thrown around.
    • Murray_Calavera
      R32 GTR - Where to begin

      By Murray_Calavera · Posted

      It's interesting seeing everyone talk about what level of risk they are happy to tolerate.  Building a GTR always has a level of risk, you could be that lucky guy that drops 20k on the engine build alone and still has the thing go pop on the dyno. Life is fun like that.  The way I see it, the thing is a toy to be enjoyed. I'd be happy to turn up the power on stock motor and limit the risk with sensible tuning and engine protection. If it still goes pop, it is what it is. The car isn't a daily driver so it can happily sit while a plan is made to sort it out.  Given this thing will be a street car only, I really feel it's worth the (relatively small if managed well) risk to turn the power up to around 350KW on e85.  I don't think anyone getting into the skyline game now is doing it out of logic. Surely it is a purely emotional decision so I'm not sure how important it is to think about the engine build logically. The heart wants what it wants.  @joshuaho96 little note for Josh, I run my 525 pump flat out all the time and through the factory lines without any issues. (excluding the melting connectors, that's sorted now. we'll pretend it never happened lol)
    • joshuaho96
      R32 GTR - Where to begin

      By joshuaho96 · Posted

      But the Nexus S3 is very expensive and won't be as purpose-built for the application as a separate electronic boost controller :^) More seriously my pet issue here would be that the Walbro 525 running at 100% duty cycle is going to require more FPR than the stock setup can handle. I'm also pretty sure from what I've seen elsewhere you might want to slow down the pump regardless unless you're going to come up with some way of upsizing the fuel lines coming from the fuel tank. Factory 8mm fuel line doesn't actually flow very much if you want to keep pressure drop down between the fuel pump outlet and FPR. If you really want to "keep it simple" I would run only as much pump as you need and source a fuel pump controller to slow down the pump in the vain hope of being able to run stock-style FPRs which are pretty dinky. Or just use the HICAS lines and it should be mostly fine. OP should also really think hard about what profile they'd want out of the turbo. My pet choice here would be the G1 profile rather than anything higher power but YMMV. I already think ~stock turbo lag is pretty bad so I don't want to make it worse. In "gentle canyon cruising" I found that I spent a lot of time around 4-4.5k RPM. I also recommend DIYing labor if you're detail-oriented enough. Costs are high for labor + if you do it yourself you can be your own quality control.
    • Kinkstaah
      R32 GTR - Where to begin

      By Kinkstaah · Posted

      GTSBoy is again on the money. My actual advice? Sell the car. (really). For what it's worth as is, you can sidegrade into something much better. If you care about function then this is the actual move. If you want a Skyline to perform, set aside about $100K to do it. This is NOT a typo. You will see right away these are two very different mindsets. Realistically we're talking full restomod for any Skyline still kicking around. Have an honest think about which one you are.. and what you want to do, and how much you want to invest in this (with no return).
×
×
  • Create New...