Hicas, What Does It Actually Do

[ebola]

Weighty steering isnt a bad thing, I prefer it

Kushil Abeysinghe,

We dont see much of Germany, we just drop in through Belgium then a quick blast and we are at the Ring. No autobahns on the way

http://www.multimap.com/map/aproute.cgi?cl...e_pan〈=

We have been tot he Ring twice before, both times in an XJR Jag. Great car and a lot of fun but Im really looking forward to taking the Skyline, it whould be pretty mind blowing in comparison to the Jag

We have been having overheating issues with the Skyline despite fitting a Greddy rad and 19 row oil cooler so we are now halfway through fitting a 34 row cooler right in the mouth of the bumper. Ill be bolloxed if the cars going to overheat with this thing fitted! Ill get some pics when its in later today, it should look really cool. And of course work well

There was a thread on overheating / radiators / cooling system issues that was active a little while ago. If you still have overheating problems, perhaps you should dig it up. Synopsis seems to be a high swirl pot will help (and remove any air traps, etc)...

good luck. And on the hicas, try unplugging the ecu and taking it for a fang somewhere you can. The hicas should disable itself automatically, and you will have an indication (and no power steering for the duration of the test) of how much the active hicas works. When disabled, it should lock itself straight (If not, there are enough people who should know who have replied to this thread).

[R33S2]

Oh nooes wrong Thread!

[bren]

Ill have a look for the overheating thread

I unplugged the Hicas ECU last night and it made a huge difference to the steering effort so I plugged it back in.

[Kinks]

We then take the car to the track or get it loose during some spirited driving and the HICAS gives us understeer into a corner, so the driver turns in harder and eventually some oversteer may occur. The driver then corrects oversteer by turning on some opposite steering and the HICAS follows pulling more oversteer into the equation. We now enter tankslapper phenomena and this is exacerbated by the useless viscous LSD in 33's which are easily overpowered once hot. As the inexperienced driver tries to correct and stay on the gas to keep going the car becomes more unstable as the HICAS keeps dragging the rear about, eventually going around and all to often hitting a wall at the track.

I'll preface this by saying I've not driven a HICAS-equipped car on the track and every post I read seems to have a different opinion of how it works, but if the HICAS is acting to help turnin (ie opposite turn to front wheels, oversteer) I can see how the tank-slapper happens. If it's acting to create understeer (same direction as front wheels) this should actually help pull the car out of a slide.

I've heard claims of R32 GTRs basically throwing people into the sand trap because of HICAS, so maybe what you're saying about the 32GTR being more rear dominant is true (yet, it MUST be quicker.. otherwise why would they do it that way?).

Which leaves me with my S2 GTS-t, I think I'll be leaving HICAS alone if it makes the car feel more stable when you're doing "80%" driving.. because I'm sure as shit not going harder than that on the road!!

[GTRgeoff]

You have to remind yourself just how many things put into cars are just gimmicks for marketing. Back then 4WS was the big gimmick on Japanese cars. We know it was a gimmick because it's almost completely gone. I used to operate 20ton 4WD 4WS cross country cranes which can counter and crab steer, as well as reverse the steering input if the boom is over the back. Not a gimmick for getting that big sucker through tight areas but in cars....useless.

I've driven a number of different types of race cars from rally, formula ford and sports sedans as well as R32/R33 GTSt/GTR and front wheel drives with and without 4WS. I can honestly state that I can feel the rear moving about in the Skylines with HICAS and I prefer the natural and progressive consistency of the rear being straight, without input from a rear rack at speed. Low speed 4WS makes no difference as it's for parking.

The big thing is though that not everyone pushes it hard enough or has the feedback sensitivity to warrant a change, but that comes through experience. If it works fine and you don't feel it impact then leave it alone.

The way HICAS pulls the car around is after you lose rear traction. It works in phase with the steering input, so once you wind on some opposite lock it turns the rear wheels in the same direction which tries to pull the tail out. It only turns a bit so unless you can be pretty quick on the wheel it goes threough a transition stage then stops at 1deg so you can be constantly correcting for it, especially if you are in second gear with the rear loose and right on the threshold of the HICAS activation speed of around 80kmh.

There are other things that help to destabilise the rear end as well like the subframe bushes which I could feel squirming around during turn in, but they also are easily fixed.

Part of the drama of owning an ageing car is the need, especially if you go to the track, is constantly inspecting for things that might be about to let go so going to track is a good way of motivating to keep the car tip top.

[Kinks]

The way HICAS pulls the car around is after you lose rear traction. It works in phase with the steering input, so once you wind on some opposite lock it turns the rear wheels in the same direction which tries to pull the tail out.

Ah yes, right you are.. I wasn't thinking about it enough