R33 Hicas Refresh

[Team7]

Ive got a 95 GTR and when the car squats I feel the car kick out in the rear.  Its not tires getting loose but rather a toe issue.  The car might just need to be aligned but when jacking the car up and shaking the wheel there is a very slight perceptible movement.  I am going to replace the rear tie rods but trying to figure out what I need to replace. 

Do I need to do just the ball joints or should I also do the outer and inner tie rods?  

[GTSBoy]

If it is the HICAS that is loose, then it will be the outer ball joints on the tie rods, not the tie rods themselves that need to be replaced.

If I was having to do that job, I would be doing the next logical step and binning the entire HICAS shitstorm, which banishes those stupid ball joints and all the rest of the stupid HICAS along with it.

 

[Milkmun]

Full hicas eliminator kit will solve your issues, not just a hicas lock out bar.

[Team7]

Well crap, I figured Id get that answer and I had thought for the electronic HICAS people would keep it.  I have a Z32 that I have removed it completely from.  Ill need to give it some more thought but you guys have set me on the right track.

[GTSBoy]

8 hours ago, Team7 said:

and I had thought for the electronic HICAS people would keep it

The hydraulic part of the R/Z32 era HICAS is not the bad part. It's the brains of the operation that is the problem. Just not clever enough to do what it is supposed to do without trying to throw you off the road when you're driving above 7/10ths. And of course, the additional unnecessary wear points in the rear end.

[Team7]

40 minutes ago, GTSBoy said:

The hydraulic part of the R/Z32 era HICAS is not the bad part. It's the brains of the operation that is the problem. Just not clever enough to do what it is supposed to do without trying to throw you off the road when you're driving above 7/10ths. And of course, the additional unnecessary wear points in the rear end.

So from what I have been reading it seems like if you eliminate the HICAS through either a block plate or other means it causes the steering to become heavy, somewhere between no power steering.  Has this been resolved outside of swapping in a different steering rack?  

[GTSBoy]

It's not true.

The HICAS CU is the module that controls the assistance of the front rack (as well as doing what it does with the rear steer). The solution when ripping out all the HICAS stuff? Just leave the HICAS CU in place. It will still do the speed sensitive front steer assistance.

At least....it does on R32. I can't promise it will on R33. But I can't see why they would change the system that much - the brains are basically the same - it's just the rack changed to electric actuation.

On the R32, because my HICAS was faulty (aftermarket steering wheel had no position sensor, so the HICAS CU would go into a spaz state at >80 km/h and activate the isolation solenoid to the rear rack, which was not working properly and caused the rear rack to steer which caused me to need to wind in a half a turn of lock to keep the car on the road, which is just f**king stupid), I simply pulled one of the connectors out of the back of the HICAS CU. I can't remember any more if it was the smaller or larger connector, but whichever it was - the power steering remained normal and the HICAS stopped panicking and there was no HICAS light on the dash (because the light is fed from the connector I pulled out!). You have to leave one of the connectors and not the other. On the R32 that is. On an R33, it might instead be necessary to pull a wire or two out of a connector instead. You'd need to look at the wiring diagram to see.

Then, after driving like that for years I just swapped out the whole HICAS subframe for one that was non-HICAS, along with the non-HICAS toe control arms (which gets rid of the the tie rods and ball joints in favour of normal bushes - which are now steel spherical joints on my car), and deleted the hydraulic equipment and replaced the PS pump with an R34 one (which was easy because it was attached to the Neo that I put in the engine bay). 25 years after the first HICAS fault, it is still otherwise normal.

Edited August 11, 2024 by GTSBoy