Why Disable Hicas?

[DaveO74]

Hi everybobody,

Can you guys answer a stupid question for me?

I read in a hell of a lot of threads on these forums about people locking thier Hicas and was just wondering what the benefits of doing this are? Is it for handling or for traction?

I know its a silly question but how do you learn things if you dont ask questions eh?

P.S. Sorry if this is posted in the wrong section

Dave

[WAN73D]

i'm no expert but to get the ball rolling for ya i think most people disabel it cos it just plain stuffs up

i think it only really comes into operation at around the 80 km/hr mark (could be wrong) and it just allows the rear wheels to steer by like 1, 2 ,or 3 degrees, if u were deciding to do a U-turn at this speed.

i think there's a few people on here that get the locks because of a near scare they may of had with it stuffing up on them at over 80 k/hr...others just see the light come on on the dash and the easiest solution (i think) is to just lock that crap up.

i really think its sorta useless

so in short i dont think there are really any benefits ...maybe in extreme racing conditions???

i haven't had any troubles from mine tho

that's what ive read on these forums

but i welcome corrections

[Basti]

hicas is a 4ws steering system that you have no controll over. say if you are taking a corner at a certain speed and you've picked your line and all that stuff (i dunno i dont race), hicas may decide to kick in unexpectedly and change the way you car handles. like mentioned above it only kicks in above 80 or so km/h so not really a problem in daily driving. but twisties and onn the track is a different story

[Hardman69]

I "THINK" it rear-steers a little bit below 40km/h (like the 4ws Prelude) to kick the rear out, and it DEFINITELY steers into turns above 80km/h, more so as speed increases, to weight-up the steering and stabilise the rear-end. Some people will tell U that it's only to make the car change lanes more squarely on the freeway (slight crab-crawl), but that's crap. I've got a dodgey speed-feed to my HICAS box, which disables it if it's without signal long enough, and I can assure everyone, that the meaty steering feel that (working) HICAS brings is SWEEET. Get used to it, and Learn to trust it.

I think alot of people get creeped-out by the rear-steer intially (I did), and alot of folk get electronic gremlins (like Me) which messes with the HICAS Computer, hence the large numbers grabbing lock-bars. When it's working properly, I think it's a terrific asset. It seems NISSAN did too, or they would've dropped it after R32, instead of making a new electric rear-rack for the R33.

[HotPlates]

I had the impression HICAS engages at 50+km/h. I'm no expert, but I think some people get the HICAS locks so they can drift better.

[DRD-00F]

i honestly have no idea if mine works, ever did work or what its supposed to feel like...

when its doing its thing, does the HICAS light come on? cause thats never happened...

[Hardman69]

when its doing its thing, does the HICAS light come on? cause thats never happened...

The orange light only comes on when the HICAS shuts down, 'coz it's got a problem. When it's working normally, You'll feel it tweak at the rear wheels when you're slooowwwly turning in to long fast corners (e.g. freeway curves @130km/h).

[salad]

The reason it is removed is because it is unpredictable, the sensors, actuators and controller are just too slow. It will start doing things at the wrong time etc. Also, same with all auto control systems it assumes that there is nothing else trying to control the system, but the driver will be trying to compensate all the time (naturally) so it will be correcting for your correction of it's correction etc etc.

For driving on the limit, it just a much better idea to lock it as it's much more predictable.

[9krpm]

it's great for low power gtr and it certainly makes the car feels a lot lighter and smaller

however with the extra horses it's quite unpredictable/dangerous around corners and best to be removed

[eMsta]

hicas is a 4ws steering system that you have no controll over. say if you are taking a corner at a certain speed and you've picked your line and all that stuff (i dunno i dont race), hicas may decide to kick in unexpectedly and change the way you car handles. like mentioned above it only kicks in above 80 or so km/h so not really a problem in daily driving. but twisties and onn the track is a different story

yep..was speaking to my dealer a couple of months ago, he said, they had put an r33 on a hoist and checked how much the rears actually turn - and at 100km/h, its not much really. Personally, I dont see the point of it. I have driven other rear wheel drive cars without 4ws, and hicas does not make a difference - for me anyway.

[Hardman69]

Now that I'm used to what it does, I'm fine with it. It weights-up the steering (with the extra rear toe-in) quite a bit at high speed, and doesn't seem to mess with my car too much at all. It certainly felt fine at 170km/h through T1 at Phillip Island!!! It doesn't need to turn much, btw - very slight toe changes at the rear make BIG handling & feel changes. That's why misbehaving HICAS is SUCH a Fv(KING MENACE ! !

Each to their own though I'spose.

[NickR33]

I still have it active... don't really notice it much other than at PI as stated... and all I really notice is that is makes the rear slightly vague on turn in, almost as if its threatening to step out... but once settled into the turn its fine

I have heard opinions that it makes it hard on corner exit to get the power down but my shagged stock diff is the biggest problem there so I can't say for sure

[SKYPER]

HICAS can cause excessive oversteer when exiting a corner.

Basically if you add alot of power around mid corner, rear of car steps out.

I guess it depends on how hard you push it. I noticed with R34 GTR, a

smooth driving style seems to help in preventing this oversteer problem

on the racetrack.

From what I understand suspension changes can reduce this oversteer.

But doesn't feel the same as a car without HICAS.

When HICAS is removed, the rear feels more stable through corners

and on the motorway. It's so stable that the car tracks in a straightline

on the motorway.

But the downside is understeer around mid corner when cornering.

This understeer happens on a 90 degree type of corner. With sweeping

corners it feels similar to having HICAS but the rear follows where the

front wheels have been. Basically it doesn't feel like the rear wants to

break traction when exiting a corner.

Also watch out for little bumps in the road / racetrack, as the rear could step

out a little bit. Also smooth patches or painted lines on the road / racetrack

could make the rear step out a little bit, especially when wet.

Also reduces the bodyroll, even with stock suspension. And rear of car

feels stiff.

Have a look at this link below (road diagram on left side), as it shows

you what a Skyline handles like, with and without HICAS -

http://www.ne.jp/asahi/tomosang/skyline/da...i/photo/z17.jpg

Left side is without HICAS and right side is with HICAS.

Edited May 21, 2007 by SKYPER

[Beer Baron]

my experience with HICAS. I had no real problem with it at all. it did add to some mid corner vaugeness, and it also sometimes made you think the rear end was sliding/moving around when in fact it wasn't, it was hicas adjusting the attitude of the car. again, I didn't really have a problem with it, but I have locked it (using tomei controller and shims). for a couple of reasons: I wanted more direct feeling in the rear end. and i now have one less point of failure. and I can now set the rear end up and know that the alignment I dial in will stay that way.

[ydawak]

When i first bought my car... the first day was in thr rain and the HICAS was a really weird thing to get used to. It felt like it was going to step out all the time around every corner (hwy driving) But recently the thing has just stopped working and the dash light seems to come on all the time. I think that it is much better to drive when it is off. But like has been said before i suppose it is each to their own. -Just a strange thing to get used to though..

[RBwhatever]

I had a similar experience to Beer Baron. Normal driving its fine.

But when exiting sharper corners at speed, it feels like the back end is kicking out and sliding a bit, when in fact it wasn't, it's just the hicas re-adjusting. I don't really like that feeling.

[Kinks]

I love the way my car handles, and I'd only remove the HICAS if I was doing serious track work and noticed it as a limitation, or it started malfunctioning.

[deant1]

Do they lock/ remove HICAS on professional racing cars? I imadgine they do for Pro drift for obvious reasons. But iv got a feeling it is there for a reason.

Anyone know? does Z tune GTR have it?

[FineLine]

I guess i am a purist in that I have not A. disconnected the hicas, B. disconnected the ABS, And C, removed the alsd. I am on stock brakes with basic mods but i have dragged, skidpanned and sprint ran the car around qr and even with stock suspension I can honestly say it is the most predictable handling car I have driven to date.

I read where those with hicas cant wait to get rid of it and the same with alsd. I am thinking the combo of the 2 may just be all that and more as neither of them have given a moments trouble. The ALSD is in fact the most reactive diff I have ever used and I hope and pray it holds up when I go full mod. Given that it is basically the gtr rear end I am quite confident it can handle some work.

I feel no tail wiggles when cornering and the car has a very neutral feel to it unless I try to over power it in which case the diff and the hicas step in and make the correction allowing me to carry the extra speed quite comfortably through the corner. I am sure that without it I would have spun on more than one occasion or at least have to make major steering correction to keep it on the track and going forward.

On the skidpan the car was among the quickest there despite having the lowest mod level. On the timed wet to dry dry to wet segment only one car (gtr) posted a quicker time and again i atribute it to the above mentioned features. The diff just grabs the car by the arse and holds it in place. The skidpan is an ideal place to actually feel your hicas working for you too. Your car can be moving at around 30/40 kph but the wheelspin can be anything, especially if you are in third. The hicas to some extent can prevent understeer by allowing the back to come around more easily.

At the strip I initially had issues with the diff as it was single spinning but as I used it more it simply came in to its own and now i wouldnt part with it for quids. I am guessing that being an unraped car it had probably mever been in a situ where the diff actuated and it simply needed some action to get it working.

Until any of these features give me trouble i am more than happy to stick with them as I have seen only benefits to date.

[SKYPER]

They do lock the HICAS on some racecars.

The red coloured Bathurst R32 GTR would be one example.

It looked like they used the stock HICAS rack but locked it

and sealed the inlets up.

Edited May 21, 2007 by SKYPER