Has anyone lost the rear of their 300ZX in an unpredictable and immediate way?

 

On a wet road and coming off of a roundabout some weeks ago, the rear of my car "flicked" sideways. I was running in a clutch and know it was a soft-foot acceleration. The roundabout exit has a ridge and an unusual camber, which with the wet road could have contributed. The sideways "flick" was not predictable, and really instantaneous. Has anybody else had this happen?

 

I spoke yesterday to a very knowledgable person, who a number of you would know. The following is my interpretation. The HICAS is great in the dry and helps steering by "flicking" the geometry on the rear wheels (as we know). In the wet this could be a totally different senario. HICAS is fitted to all TTs (not NAs I believe), and 3 TTs had perhaps suffered accidents like this that this knowledgable person had recently seen.

 

A recommendation is to remove the fuse for the HICAS, which results in the rear wheel geometry being locked and working like a conventional car rear.

 

I would be interested to know if this has happened to you (e-mail me if you prefer).

Also, any thoughts/comments on removing the fuse?

Thanks, Geoff

 

 

Hi,

My NA hasn't got Hicas, and the back of my car can step out on a wet road...Although being non-turbo, it is less likely to do so.

It's just the fact that you have a powerful rear drive car, that needs respect in the wet!

HICAS was an option on the NA's by the way.

JEZ

 

I've personally never heard of HICAS causing problems like this but there's a first time for everything ! However, I would have thought that the small amount of steering provided by the rear is unlikely to be the main cause of the problem.

 

More likely (IMHO) would be a bit of diesel on the road or something like a manhole cover.

 

If it does feel as though there IS a problem with rear geometry, I'd check out tyre pressures first (mine is VERY sensitive to the right pressures), and then all suspension & subframe bushes plus wheel bearings for play.

 

Finally, think about the power of 300 horses being pushed through what is actually a tiny bit of rubber in contact with the ground. Then put a layer of water in between ...

 

Dave

 

You get used to it.

Just carry some clean underpants ;-)

Paul

 

Yup yup...had exactly that a while ago.

I was driving in third gear, no throttle and in a 70 degree corner and all of a sudden I went almost completely sideways.

*Totally* unexpected..well, sort of..

since you can expect anything to happen in a 400bhp TT ;-)

 

-Eric

 

Have had my Z do some strange rear-end stuff in the wet but it's been down to crappy ESSEX roads covered in oil and petrol and other stuff.

 

I have spoken to Pete @ SE about disabling the Hi-Cas which can be done using a product made by Stillen. From what he said it seems to be only people who have 500bhp + that experience unusual handling features realting to Hicas.

 

On tt.net they talk about bypassing Hicas a lot.

 

I have just uploaded this so you can see what hicas does: -

 

http://www.btinternet.co.uk/~dave_edwards/Site/hicas.htm

 

Hope it's usefull

 

Ta

 

Eddie ;-)

 

I've had it happen 3 times. Each time it was wet and one of the rear wheels was on a white line.

 

i buzz off the hicas in the wet and the dry as it helps to switch from doughnutting one way to the other without having to have arms like a gorilla......its top and im gonna leave mine just as it is

 

Have a look at this research that Henri Le Hir did on the HICAS system last year. The title of the post is "Droit de Réponse / HICAS" posted on the 5th of December 2000. Indepth and interesting reading.

 

http://www.twinturbo.net/cgi-bin/ttnet_viewmsg.pl?forum=main&msg_id=630544

 

Trev.

300ZX.CO.UK

 

I lost my back end unexpectedly the other day after a bloody good curry washed down with several cans of stella. I'm gonna check my hicas.

 

My thanks to Eddie for the info and lead (I use to live in SWF). I saw Henri's write-up also through this (Trev how do you insert the links into your reply?).

 

However I also found the following extracts there, which are food for thought:

 

- Michelle June 22, 1998

… We were getting on a highway and the HICAS system kicked in and it put us in a spin.

- Michelle June 23, 1998

... When I say that the HICAS system kicked in and put us in a spin, it felt like the back end just jumped to the left briefly and then by the time he corrected it, it spun us around fully to the right.

 

- SnuffyZ32 January 11, 2001

... I also encountered twice in 4000miles that i have my car now, that in the middle of a steady corner (at like apex point or something) i got a sudden short strange twitch/jerk/unsettlement of the car. Felt very unnatural and it couldn’t have been a bump or anything. I'm 90% sure that HICAS twitched there. Made a mistake with other words. I wasn’t near sliding or breaking loose, or anything either. I was just doing a fairly quick speed, you know, normal driving, at least in Europe.

 

Thanks, and I appreciate any further info. Geoff

 

 

I posted a subject over the same thing about a week ago, (Dan loses his Z!). I lost mine big time, ended up doing a 720 on a country lane, not my iodea of fun nor was it the people coming towards me and behind me. These cars are lethal in the wet, anyone who would say that the driving has top change in the wet on these is correct. I pootle around with my TT 2+2 Jap impoort when it rains but in dry conditions she is a star. When I spoke to the people on the forum, the general impression to me was that I must learn more repsect for a 320 bhp rear wheel drive car in the wet, basically, when it rains, I cruise and love the noise of the v6 engine, but when it is lovely and dry, I let her rip. Scared the shit out of me when it happened so I understand completly.

 

#dan

 

p.s sorry for the typing, using someone elses keyboard and it is ponyt!!

 

Maybe its the HICAS. but the smart money is on a bunch of other less dramatic things. Like Hairsy suggests, tyre pressures, tread, diesel on road, heavy right foot, etc. Or all these in comboination. If HICAS was this dangerous I reckon Nissan would have figured that out pretty early in the development. Also could be the rear steering rods which if they wear cause the back end hops.

 

Interesting though, the latest Z's got rid of HICAS didn't they? - so is it any good anyway? 1 degree change in rear wheel can't be that hot can it?

 

Get yourself Racelogic traction control with Bridgestone S02s and banish the rear end stepping out (well, unless your try very very hard).

 

Mozart

 

Just to add to Mozart's post, I did suffer from rather regular back end problems in the wet until I had traction control fitted. Since then I have never had anything unpredictable happen. My driving style has become more enthusiastic in the wet since fitting which confirms my suspension that it was just a horsepower thing for me.

 

Don't get paranoid about HICAS - it really does do only a minor job in the grand scheme of things.

 

Dave

 

i had my back end step out un expectedly twice the other day doing about 15MPH on thous stupid thick white lines at junctions and on the stupid humps in the road

 

i had my back end step out un expectedly twice the other day doing about 15MPH on thous stupid thick white lines at junctions and on the stupid humps in the road

 

Stacks of horsepower and wide rear tyres are always a recipe for fun 'n' games in the wet. I love driving in the wet, but am seriously considering traction control after a few heart stopping momemts.

 

B4 checking your HICAS, check out the condition of the rear shocks first. I was told by Mr. Ford at Arriva Nissan in Peterborough, that the unpredictable behaviour was being caused due to a knackered shock on the rear right.

 

My car was not safe to drive in my opinion, I would shit my shorts on a regular basis due to this problem. Car would crab from right to left really violently and unexpectedly.

 

Try pulling the handbrake up one click and see if that calms the problem down. This sets the stiff mode on the rear suspension. Trust me, it does work as Bob demonstrated it to me in my car while we were test driving.

 

Hope this helps...

 

Tim

;-)

 

Does this stiff mode work for imports, or do I have to take mine apart to find out ?

 

...as far as I know they should all have this option. As maybe Nico mentioned in some other posts, only yank tanks were given the nice little button inside the car to switch between sport or normal settings. Don't ask me why nobody else gets these gizmo's. In my opinion if the car has the ability to use the function then why not let everybody have it!

 

Nico or Henri should be able to confirm this for you...

 

But try it anyway, one click only remember! I don't want to be responsible for loads of people knackering their brakes coZ of moir.

 

Tim

;-)

 

 

Don't forget that the Skyline still uses Super HICAS...

 

Also, don't want to upset everybody, but I'm not sure about this one, maybe someone else could confirm this.

 

If you ditch the stock Nissan rear shocks for say Koni's etc. Do you lose the ability to stiffen the suspension or is this gadget seperate from the actual shock???

 

I would look on my car if I ever get it back from the garage...large sighhhhh!

 

Tim

:-(

 

On the adjustable shocks theory...

 

The stock shock absorbers on the TT cars are 2-way dial adjustable. The sport mode is much stiffer than the touring mode.

 

The switch inside the cockpit on US cars is the actuator control switch for the shock adjustment. The little grey discs that sit on top of the stock shocks have slots in a motorized turntable on their undersides...when you flip that switch, they rotate (45 degrees/90) turning a tab on the shocks that selects the stiffness setting.

 

Aftermarket shocks have rendered the cockpit switch useless, as their settings are not controlled in the same manner and your stock actuators aren't connected to anything now.

 

Hope that clears that one up guys.

 

Later..