The HICAS

[Kiven422]

I'm just curious what does everyone thinks about the Q45's HICAS (4-wheel-steering) system? Couldn't find much in search

There is a lot of extra control especially cornering at very high speeds over bumpy roads but its more effort to turn the steering wheel and i would like to tighten it up a little bit for more response

How does it react though? At a stop when I turn the steering wheel I don't see the rear wheels turn AT ALL. On my 88 Honda Prelude w/4WS if you turned the front wheels to the left, the rear would turn slightly left... if you turned it a lot the rear wheels would turn right.

[MinisterofDOOM]

Rear steering from HICAS is much more minimal than on Hondas 4WS. It is visible, though, if you're looking closely at the rear wheels while someone steers to full lock.

Consider how much impact having any one tire even slightly out of alignment and you'll see where HICAS's benefits come in. A little nudge here or there can have a pretty big effect on the car's dynamics.

Here's a cool illustration from Nissan:



It's interesting that you'll see a good number of people who drive their cars on tracks complaining about the way HICAS messes with the car's predictability. I'm not sure if it's in their heads, or they just need to get used to the different feel, or if it really does get in the way. I've only driven a car with it once and that was before my years as a Nissan-phile; I didn't know what HICAS was to note the effects.

[Kiven422]

I could understand how it does get in the way sometimes like when I'm trying to do a donut its harder to get the car to "whip." Thank you.

[captainluigi]

Just curious, were there any Q45a w/HICAS?

[maxnix]

I could understand how it does get in the way sometimes like when I'm trying to do a donut its harder to get the car to "whip."

Yes, it is there as a refinement to initial directional change, but it does somewhat deter owner abuse.

[Haitian_King]

I don't rightly know what my Q is. It's not an a or a t, but I have TCS, so it's not a super stock base model right?

I don't know if mine has HICAS. My friend had it in his J30t, but I don't remember any specific indication of it's presence. How can I tell if my Q has HICAS? Or is it something that all Q's are born with?

[Kiven422]

Yes, it is there as a refinement to initial directional change, but it does somewhat deter owner abuse.

Hehe. Yes I don't treat my car like a sports car anymore. While in the sky I realized it would fall apart step by step. Now I just drive and pray for better mileage.

-Haitian KingOne way to tell is if you have a HICAS light next to your CHECK ENGINE light. The difference isn't much, they both drive the same. I was expecting tight cornering when I got my Touring model but no matter what you just can't toss a 2-ton boat into a corner like a Honda Prelude.

I read in the Q45 manual that Q45s have Super HICAS. Then I read that 1990-92 300ZX TTs came with HICAS which is hydraulically controlled and 93-96 300ZX TTs came with Super HICAS that is electronically controlled. So which does the Q45 have because the steering has some extra play...?

[Haitian_King]

Thank you Kiven. For a sec, I thought I was on the wrong board. I couldn't believe I was seeing a helpful, positive comment, completely absent of low brow wit and condescension. Wow. Thank you.

I don't think I've ever noticed it. I'll look for it the next time I start the car.

[StarPD]

Unless your car is a pre-95 "t" model, it does not have "HICAS". '95 up "t" models no longer had "HICAS".

Or if you like, you can look under the rear. HICAS equipped models have a lot more "machinery" than non-HICAS cars there. They also have additional hydraulic lines from the PS pump to power the system.

My '94 "t" model had it. It made handling sharper and quicker. In fact, my first '94 was a standard Q45. After learning about HICAS on "t" models, I bugged my dealer to find one for me. It took 6 months, but they finally found one. I traded the standard Q in on it, and never regretted it . Best car I ever owned. I still like my '05 a lot though.

[Haitian_King]

Unless your car is a pre-95 "t" model, it does not have "HICAS". '95 up "t" models no longer had "HICAS".

Or if you like, you can look under the rear. HICAS equipped models have a lot more "machinery" than non-HICAS cars there. They also have additional hydraulic lines from the PS pump to power the system.

My '94 "t" model had it. It made handling sharper and quicker. In fact, my first '94 was a standard Q45. After learning about HICAS on "t" models, I bugged my dealer to find one for me. It took 6 months, but they finally found one. I traded the standard Q in on it, and never regretted it . Best car I ever owned. I still like my '05 a lot though.

Thank you sir.

Quite the clear and concise answer. Good to know. I have no complaints about steering, but if I get the chance, I'd like to compare it to my 92.

[Q45tech]

The less than 1 degree rear toe changes [so called rear steering] often goes unnoticed by many drivers as they are use to it in the conditions where it occurs.

Many of the old T cars have never had any of the rear rubber bushings mounts, arms replaced so the sloppyness of the rear further NUMBS the effect of the HICAS.

[Kiven422]

Yes I very very realize that. Slowly I will rebuild the rear... Would really like to see HICAS in full effect. I've replaced the rear 16MM bar with a Q45a sway bar and its a lot better but lot less noticable now. It also gave me a slightly more negative camber.

[maxnix]

I've replaced the rear 16MM bar with a Q45a sway bar and its a lot better but lot less noticable now. It also gave me a slightly more negative camber.

Really? It shouldn't, even if your link rubber had evaporated.

[Kiven422]

Yup the camber change is noticeable to me and a couple of friends that have the keen eye for my car.

[Q45tech]

No way can a rear sway bar change static camber, now the reduced body roll in a curve can reduce what ever camber gain is built into suspension but not rolling the rear 1/2-3/4" [16-20%] at max G is pretty insignificant in the total amount of camber.

[maxnix]

Yup the camber change is noticeable to me and a couple of friends that have the keen eye for my car.

Keener than a laser based Hunter system?

A little specific before and after data, please.

[Kiven422]

Hah whatever... It just sits out a little bit more on the bottom of the wheels... this is by "looking at it." No real difference though, I would say the bar did what it was designed to do.