Removing Hicas

[mature gent]

Hi A newby question,some guys are removing the HICAS,why,is it troublesome

Cheers

[lachlanw]

they dont like the feeling . if you arnt building a track car leave it alone

[jrm]

You have to consider that the skylines we have are typically 10 years old, and local mechanics are often unfamiliar with HICAS. It's very easy to mess up your alignment or steering rack and cause HICAS to cause steering issues. Additionally, after 10 years, the sensors can mess up and require expensive replacement. Many people fit aftermarket steering wheels, and these require HICAS compatible boss kits.

On a track car, and at the extremes of handling HICAS can upset the balance of the car as the HICAS will counteract the steering imputs you're trying to give it in it's attempt to straighten up the car.

For regular every day driving, and highway driving I personally find HICAS useful, you can feel it at work changing lanes, going around corners at speed, etc - but I've also experienced how unpredictable it can make the car feel at the limits.

One consideration for those removing their HICAS is to ensure that they get it engineered (though most don't bother); Removing HICAS is a defectable item if an inspector catches you.

[Curmi]

as above hicas system is over 10 years old and can be faulty and turn on/act at times it shouldn't, for example driving in a straight line then you feel the rear end is making you sway right or left, it can actilly be very dangerous, mate in his 180 has had this happen to him and he got a lock bar straight away, lock bar replaces the rack and blocked the hicas fluid lines, this is fine and works really good,

[PM-R33]

Plenty of threads about HICAS, just search and start reading.

In a modified car that gets driven hard it causes a bit of unpredictability that most people don't like. Not to mention in a R32 you get rid of a heap of weight.

Edited May 30, 2010 by PM-R33

[Curmi]

but to remove the whole system is a headf*ck so many lines and shitt lol better off blocking it.

[lookingforboost]

there isnt that many extra lines, swaped over racks and pump etc to take the hicas out of our 180 once and for all

[Birds]

I put in a lock bar last week and I can't notice much difference through the course of daily driving - as you won't unless the system is faulty. Only when driving spirited through corners will you see much "improvement" from locking it. I say "improvement" because if you don't notice HICAS doing its job then you aren't really going to notice a difference without it...

It's a shame our HICAS isn't like the four wheel steering that the Preludes from late 80's and early 90's got - it was only active at low speeds and was AWESOME for parking / low speed manouvres. Made you feel like you were in a boat because the car would almost rotate on the spot lol.

[Cowboy1600]

I'm pretty sure I hate it.

I'm sure I can feel the car rear wheel steering all over the place when I get it some herbs.

I won't know for sure that it's the HICAS until I remove it, but I'm pretty sure that's what it is.

[TurboDoseBro]

Sounds like a good project. How much weight are we talking about reducing in an R32?

Edited May 31, 2010 by TyresBro

[HtwCHACtkh]

  Birds said:

It's a shame our HICAS isn't like the four wheel steering that the Preludes from late 80's and early 90's got - it was only active at low speeds and was AWESOME for parking / low speed manouvres. Made you feel like you were in a boat because the car would almost rotate on the spot lol.

Surely there should be a way you can trick the ECU to make it do this.. Have you ever tried the HICAS diagnostics? Your rear wheels move when you're turning your wheel at a stand still, it feels so weird.

  jrm said:

For regular every day driving, and highway driving I personally find HICAS useful, you can feel it at work changing lanes, going around corners at speed, etc - but I've also experienced how unpredictable it can make the car feel at the limits.

I've never felt it do anything in my R33 in those situations, the light doesn't come up either. I thought it only engages over 80km/h and under extreme turning essentially inducing oversteer then attempting to straighten it up just afterwards so you can make sharper turns.

People always tend to complain about it, but I think it sounds quite cool and would be useful after getting used to it - even though I've never experienced it before.

[wlspn]

TyresBro, I would say removing pump, all lines, swapping rack for lock-bar, etc there is around 15-20kg to be lost in a 32.

Was a lot heavier than I thought...

[jrm]

  aeqel said:

I've never felt it do anything in my R33 in those situations, the light doesn't come up either. I thought it only engages over 80km/h and under extreme turning essentially inducing oversteer then attempting to straighten it up just afterwards so you can make sharper turns.

In my experience, it starts kicking in about 50-60kph, and turns off about 110kph. This diagram illustrates how it works:

I learned the speeds that it kicks in from when my HICAS developed a fault - the steering angle sensor was mis-aligned. In this situation as it believed the steering wheel was at an angle when the car was straight, the steering wheel would sorta 'roll over' trying to correct the rear wheels turning, and the car would start to crab; This only happened at speeds above 60kph and then got steadily worse up until 110kph when the steering wheel would snap-straight as HICAS turned off, causing the entire rear end to fishtail (a scary experience).

[Birds]

Shit, with stories like that it sounds like a faulty system could actually be quite dangerous, especially in the wet^

That's what concerns me about all the modern systems being put in cars...these systems put in place to take human error out of the equation yet ruling out that the components themselves were designed by humans and therefore prone to fault themselves

From that diagram it seems to me HICAS will induce some oversteer during mid speed turns, then quickly understeer to get you straightened up again. During high speed it appears to just understeer you throughout most of the turn so you don't end up in snap overtseer. I can see where it would be useful for inexperienced drivers but this will contradict driver inputs when you're trying to throw the thing around a race track - makes things very unpredictable unless you know exactly what it's going to do at a certain speed.

aequel, it would be interesting if you could trick the ECU into activating HICAS for low speed manouvres. I think a problem at hand is that the Honda system was designed to induce alot of oversteer to combat the natural understeer of a FWD, whilst HICAS is there to save newbies from the oversteer of a powerful RWD vehicle. If you ever get a chance to, drive a 4 wheel steer Prelude and you will see how good that system actually is. Feels like you're drifting around some roundabouts - I never get sick of it

[NZM.031]

i actually liked both my skylines with the hicas in... the r33 is definatly the better setup, being an electronic controlled rack.

the r32 definatly weighs a tonne... the rack weighs 6kg... the front valve weighs about the same and so does the rear valve and the extra lines, fluid, and rear pump section, hicas ecu and wiring.. easily 25kgs all up.

the rear end definatly feels better without it though, and you can set the toe to where you want it and know it wont move around... especially when you consider things like bump steer at the back when our cars are lowered... its talked about at the front but not much at the back..

[HtwCHACtkh]

  Birds said:

Shit, with stories like that it sounds like a faulty system could actually be quite dangerous, especially in the wet^

That's what concerns me about all the modern systems being put in cars...these systems put in place to take human error out of the equation yet ruling out that the components themselves were designed by humans and therefore prone to fault themselves

it would be useful for inexperienced driversFrom that diagram it seems to me HICAS will induce some oversteer during mid speed turns, then quickly understeer to get you straightened up again. During high speed it appears to just understeer you throughout most of the turn so you don't end up in snap overtseer. I can see where it would be useful for inexperienced drivers but this will contradict driver inputs when you're trying to throw the thing around a race track - makes things very unpredictable unless you know exactly what it's going to do at a certain speed.

aequel, it would be interesting if you could trick the ECU into activating HICAS for low speed manouvres. I think a problem at hand is that the Honda system was designed to induce alot of oversteer to combat the natural understeer of a FWD, whilst HICAS is there to save newbies from the oversteer of a powerful RWD vehicle. If you ever get a chance to, drive a 4 wheel steer Prelude and you will see how good that system actually is. Feels like you're drifting around some roundabouts - I never get sick of it

Like me

So it has 3 settings, Off, Mid Speed, High Speed.

I think it would be cool to have a switch that over rides the speed detection essentially allowing you to "dial in" a speed and consequently manually telling hicas what to do. So you don't need a lock bar to disable HICAS.

Unless of course it changes in behaviour from 50km/h to 51km/h.

Anyone know how the HICAS speed detection works on an R33 gtst?

[Checkbuzz]

  aeqel said:

Like me

So it has 3 settings, Off, Mid Speed, High Speed.

I think it would be cool to have a switch that over rides the speed detection essentially allowing you to "dial in" a speed and consequently manually telling hicas what to do. So you don't need a lock bar to disable HICAS.

Unless of course it changes in behaviour from 50km/h to 51km/h.

Anyone know how the HICAS speed detection works on an R33 gtst?

No, No and No

It doesn't have 3 settings or speeds.

It doesn't help you park - Honda's are for geriatrics that's why they get park assist (if you can't park your Skyline i suggest u "upgrade" to a Honda).

It does not turn the rear wheels when you r at a standstill anyone who says they can see that happening is on drugs!

HICAS is high speed (roughly 70kph+ depending on conditions) steering assistance that is advantageous under most road conditions i.e. with average drivers driving at average speeds.

Once you start driving the car at 90%+ (i.e. on the track) HICAS is counter productive and will make the car feel like it has a mind of it's own and cost you lap time.

This is not opinion but a fact - show me one serious track going Skyline that uses HICAS and I'll show you someone who doesn't know how a car should handle.

So to summarise:

HICAS on road = good

HICAS on track = bad

Cheers

[wlspn]

  Checkbuzz said:

It does not turn the rear wheels when you r at a standstill anyone who says they can see that happening is on drugs!

If you are referring to the guy who mentioned that in this thread, he actually said whilst in diagnostics mode, which is correct.

When you enter diag mode, the HICAS computer moves the rack around, testing its sensors, etc & feels trippy as!

[LANDSCRIBBLE]

my hicas has been bugging me lately, hence went and bought a lock bar today.

for instance i would briskly exit say a 90 degree corner more sharply (even a word?) than usual, and could feel the rear wheels wobbling around (no wheel spin or oversteering happening). whilst the hicas is trying to understand what the hell has this bloke just done, attempting to correct my driving by changing the direction of my rear wheels.

hello car im the driver can you plz stop farting around with my rear wheels kthx.

im especially glad i bought a lock bar after reading the above post about hicas chucking a fit and fishtailing

[jrm]

LANDSCRIBBLE - at what sort of speeds are we talking here? HICAS shouldn't kick in until 60+ (in my experience from having mis-aligned HICAS steering angle sensors).

I have had my rear wheels 'wobble around' before in situations like you describe when my HICAS steering rack had excessive movement in it - I replaced the rack and it's fine now. Perhaps get your tyre/suspension guy to check out your rear steering rack to see if it has excessive movement in it?