Hicas

[sturb25]

Ive got a series 2 RS4S with hicas and im wondering how it works and when it works, Which way the wheels turn. Ive heard that it only works at low speed but ive also heard that it work at high speed only. So i guess i want to know?

stu

[Race__24]

High speed only, above 80km/h from memory. Search the suspension section in the main board, there should be heaps there, maybe even a sticky. Yours will be the same as a R33/34.

[M I K E]

simple diagram

[M I K E]

but in all honesty, you could have simply googled hicas, as i did to find this video for you

*edit* ok how the fook do you embed on this forum?

Edited August 6, 2009 by M I K E

[QWK32]

it only kicks in around 80kph as Aaron has said. its basically an electronic actuator (motor) that controls a steering rack attached to the back of the rear subframe and is liked to the rear of the wheel hub with a toe arm. on the R32 & S13 models it was a hydraulic setup driven off the power steering pump. it turns the rear wheels only by approx 0.7 deg from center, so if your where going around a right hand bend you wheels would be something like this:

front wheels // //

rear wheels \\ \\

when you install a HICAS lock bar you remove the actuator/rack and put a solid bar in between the two toe arms to hold the rear wheel toe where you want it.

edit: beat me with a much better diagram MIKE lol

Edited August 6, 2009 by QWK32

[M I K E]

haha that video is worth a watch too

[M I K E]

ok same diagram as above but with some text

[Appealing]

HICAS is a very complex system, that is way over what most people think it is.

It helps to make a car feel shorter & more nimble, and helps to damp Yaw effect.

A long wheelbase car is easier to control but slower to turn. Rear wheel steering helps to turn the vehicle.

It has been heavily critisized for making the rear end feel loose, vauge and unnatural.

Lots of HICAS systems get taken off cars, mostly because owners do not fully understand what it is about.

It is there to make the car drive faster.

As you enter the corner the rear of the car actually gets kicked out, which reduces understeer, if you stay hard on the accelerator, as the car reaches the apex, the steering, G-sensors and throttle position will let the car "know" that it is at the apex, the rear wheels will come into phase and the car will steer straight though the apex, to take the fastest line through the corner.

It's kinda like taking a drifters line without drifting.

Your car should have the same system as the R34, which is also a model following control system.

It is pre-programmed to follow cornering models. It is not just feedback based.

If you really want to find out more about, and get a new admiration for our favorite car (sorry not the Stagea) get the book Nissan GTR by Alex Gorodji. Some of the above is taken from the book.

[Raysboostin]

simple diagram

i really hope it doesnt work that way, thats very dangerous!! if the rear wheels are turning in the same direction as the front wheels, instead of the opposite, then u r in big trouble if the front doesnt turn in. in an understeer situation, that would have the rear wheels turning u straight off the road!!

[M I K E]

read the description provided by 'appealing' above your post in conjunction with the picture. it is a complex system

[zei20l]

on the R32 & S13 models it was a hydraulic setup driven off the power steering pump.......

they changed that on S13s with the Super HICAS, it became electric on SR20 equipped model

[zei20l]

HICAS is a very complex system, that is way over what most people think it is.

It helps to make a car feel shorter & more nimble, and helps to damp Yaw effect.

A long wheelbase car is easier to control but slower to turn. Rear wheel steering helps to turn the vehicle.

It has been heavily critisized for making the rear end feel loose, vauge and unnatural.

Lots of HICAS systems get taken off cars, mostly because owners do not fully understand what it is about.

It is there to make the car drive faster.

As you enter the corner the rear of the car actually gets kicked out, which reduces understeer, if you stay hard on the accelerator, as the car reaches the apex, the steering, G-sensors and throttle position will let the car "know" that it is at the apex, the rear wheels will come into phase and the car will steer straight though the apex, to take the fastest line through the corner.

It's kinda like taking a drifters line without drifting.

Your car should have the same system as the R34, which is also a model following control system.

It is pre-programmed to follow cornering models. It is not just feedback based.

If you really want to find out more about, and get a new admiration for our favorite car (sorry not the Stagea) get the book Nissan GTR by Alex Gorodji. Some of the above is taken from the book.

i would have to agree, i had a loaner R33 sedan with hicas, and for a big heavy car, this thing handled quite well and could be easily thrown around. i have no idea why people complain about hicas so much. i think they hear that one person doesnt like it and calls it useless, then it MUST be. if it WAS useless, car manufacturers wouldnt be equipping cars with it.......

[QWK32]

I think the biggest complaints about HICAS come from anyone who has a dedicated track/drift car, or frequents a track for racing or drifting. And because every second person thinks of themselves as a race car driver or drifter they remove it based on what the real race driver and drifters have said.

Personally I liked the HICAS on my old 32 but can vouch for the fact that once the tail end is out there, it's too easy to over correct because the HICAS system is also assisting the turn.

[BensDR30]

You have to love the original HICAS implementation in the R31's - it had a couple of rams and flexed the entire K-frame on it's bushes!

4WS seems to have dropped off the radar these days, possibly due to it's mechanical complexity vs. what you can to with ESP and it's broader safety benefits.

[GT-R32]

Has anyone ever had HICAS work in a straight line? That sort of issue, giving the car a 'flick'? Possibly due to the wheel not being on straight...?

[lachlanw]

i really hope it doesnt work that way, thats very dangerous!! if the rear wheels are turning in the same direction as the front wheels, instead of the opposite, then u r in big trouble if the front doesnt turn in. in an understeer situation, that would have the rear wheels turning u straight off the road!!

open your eyes before your mouth please

[lachlanw]

i really enjoy hicas . and really notice when it comes on . eg same piece of road at different speeds . also mint for turning on hicas test and your car sits there and every 2 seconds the rear wheels move full lock (1 degree ish) one way and then other way then back to normal as fast as they can . and every one says wtf is your car doing ? "its break dancing "

[lachlanw]

i have the alex godrji book . its pretty mint aye . hicas wont work in a straight line . if your steering wheel isnt straight for a long time and high speed the error light comes on

[QWK32]

Has anyone ever had HICAS work in a straight line? That sort of issue, giving the car a 'flick'? Possibly due to the wheel not being on straight...?

only when the speedo cable snapped when i was on my way home from work, hicas started playing up along with the usual heavy steering. i was crab walking up a straight road, very strange feeling.

[GT-R32]

only when the speedo cable snapped when i was on my way home from work, hicas started playing up along with the usual heavy steering. i was crab walking up a straight road, very strange feeling.

That's exactly what I had but without the heavy steering. Definite crab walk. Happens at higher speeds like 80km/h and you need to steer into it and if slow down quick a flick out of it. I recently had work done on the suspension but the steering wheel is not that straight after the alignment and wondered if that had anything to do with it...? Speedo cable is all good.