ADJUSTABLE REAR SHOCKS

[buzz]

my 90 300zxtt has electric adj. shocks on the rear but does anyone know how to activate them?<img src="http://www.zclub.net/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>?<img src="http://www.zclub.net/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>?<img src="http://www.zclub.net/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>??
ive been told its something to do with the handbrake??
pleeeeeeeease help.
thanks
buzz

 

[AndyP]

My opinion is that they are activated automatically when you accelerate hard (kind of a crude anti-squat device) but in order to test them all you should need to do is pull the handbrake up one click.

 

[buzz]

thanks andy,
i am still looking into operation of this system as i want to make it totally driver controllable when required.

 

[Wågis]

Hi
I have rebuild the shocks so I have electric adj. shocks on the rear and front. The rear shocks can only be activated with the handbreak. What I did was to cut the earth wire which is going both to the control box for the shocks and the warninglamp for the handbreak and put a switch on the wire and the another end to earth. Then you can controll when the system will have a closed or shorted connection.
The system works as follow: When you pull your handbreak you will give earth to the system and that will give a signal to the actuator on the shocks and turn it. When you release the handbreak you will short the circut and that gives a new signal to the actuatur ,and it turn it back to the first position.
I hope you understand me, it`s hard to explain how I did it in another luanguage. You see I`m from Sweden.

Wågis &nbsp;<img src="http://www.zclub.net/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=''>

 

[Wågis]

Sorry!
Handbrake, not handbreak

Wågis

 

[Mr.F]

Your explanation pinpoints the crux of the problem - if the system changes every time you actuate the handbrake, how the hell do you know what setting the shocks are on for any given journey? As you suggest, this system sems to be begging for its own switch AND and indicator lamp for current status......

I don't drive many U.K. cars, so I haven't experimented with this, but surely someone out there has fathomed how it works on their car?

 

[dick300]

As I understand it it's pretty much as Wågis says, they only firm up when the handbrake is on. (one explanation I saw was that US spec has a dash mounted switch, UK doesn't, so they just linked it into the handbrake&#33<img src="http://www.zclub.net/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=''> Given the vast price difference between UK and Jap spec I replaced mine with Jap spec (which are the same as the firm setting on UK spec.) and did away with the actuators. If there's any difference then I'm afraid I'm just not sensative enough to notice it!

Colin

 

[Mr.F]

So what is the point of having firm suspension when the handbrake is on? Perhaps to prevent the rear end squatting when moving off from a handbrake holding situation? I have read the workshop manual again and it has a table which quite clearly says "Parking brake lever released - damping force Soft. Parking brake lever engaged - damping force Firm"! The control box is quite a complex bit of kit for simple switching, involving several ICs, one of which looks like a custom unit. What is all this for if at the end of the day you get soft dampers under normal driving conditions regardless? Perhaps U.K. TT owners should be driving around with handbrakes slightly engaged? That should increase the sales of handbrake shoes.....

 

[buzz]

well im glad i asked a decent question!!!
thanks guys for all the help ,interest and input about bouncing 300's.
&nbsp; &nbsp; &nbsp;seeing as i live in ireland where the weatherforecast is normally "scattered showers spreading to more persistent rain between the downpours of torrential drizzle" i havent as yet been able to dismantle boot compartment of my car to see shock actuators in action. however, with ignition on but engine not running, when irelease hbrake i hear activity in boot. when i pull hbrake up -more activity- just before first ratchet stop,suggesting a toggle. for the past two weeks and especially this weekend i have been experimenting on different road surfaces. this weekend confirmed operation of system while i followed the killarney lakes rally(some very dodgy roads that the romans definitely had nothing to do with)

with hbrake in fully released position; soft/rolly japZ type feel.

&nbsp;" &nbsp; &nbsp; &nbsp; " &nbsp; &nbsp; &nbsp;at first ratchet stop &nbsp; &nbsp; ; firm/a lot more surefooted.

&nbsp; crazy system,but it works. am going to fit independant control similar to Wagis.

as far as wearing pads out ,no worries, wheels are free running when lever is at first ratchet stop.
&nbsp;this explains why the handbrake in my jap 300z(which im selling if anyone is interested) feels like it is operating the brake assy much sooner than my uk 300.

thanks again guys.

Buzz <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''>

 

[Mr.F]

At last a scientist with the equipment to carry out the necessary experiment to test the hypothesis - I'm happier with Buzz's observations, but it is still a daft system. I'd be interested to know how many UK spec owners knew about this. I've never owned one and don't get to drive many and they are usually slightly sick when I do, i.e. on the way for repairs......

 

[Gio]

OK - here's the story so far. Not got to the bottom of it yet. Mike fyi. most of the 300zx lot know about this strange behaviour but haven't got a definitive reason why. But we think we are reasonably confident that
US: handbrake and dash position
UK: handbrake
J: not

Of course all 4 shocks are adjustable not just the rears.

I have been sent pages FA-20 to FA-29 of the US manual which refer and RA-20

From these it looks as if the selection switch changes from Touring to Sport and the handbrake switch changes what these settings do.

If anyone wants me to post them a copy of these pages, no probs, just post here or e-mail me.

HTH - Gio

 

[buzz]

good man gio.
i would be interested in receiving these pages if you wouldnt mind emailing them to me.
&nbsp; buzzard1@eircom.net

incidentally, i am aware of the four corner sport/touring system fitted on u.s. 300's, but my u.k. model is only fitted with rears(unless some thieving bstd took em out) . i must look for some disused connectors that may be dangling from loom!!

thanks again

buzz

 

[Gio]

Hi Buzz,

sadly I can't e-mail them as they were faxed as hardcopy. Too busy (sorry) to scan and fiddle about with 10 pages into jpg / pdf whatnot. But I would be happy to send you photocopies or fax them directly.

HTH - Gio

 

[buzz]

if you dont mind faxxing them gio, and if you think they will be legible(having been faxxed) i would be really grateful to you.
i am real interested to fully understand the electronic damping system of this car. noting where mike mentions a number of i.c.'s in the control box i cant help wondering if the system is as basic as hard/soft and may have other possible speed/ecu control functions to provide intermediate settings outside of driver control!
if you dont mind faxxing to the "always raining and not most suitable country for an uprated rearwheel drive Z " then could u send to ; 00 353 27 51581 &nbsp;and mark F.T.A.O. KEN

again with thanks gio,
&nbsp; &nbsp; &nbsp; Buzz

i hope i can be of help to you at some stage.

 

[Mr.F]

Adjustable shocks definitely only on rears on U.K. cars - no connectors to be found at front! The only connections to the control box are:
Ignition controlled 12V power in.
Body ground.
Parking brake grounding wire.
Output to rear actuators: 3 wires with parallel split to serve two actuators, one wire in common with 12V power supply.

 

[Gio]

Aha - thanks to Mike, a little light begins to dawn.
US = all 4 adjustable shocks controlled both by switch and handbrake
UK = adjustable rears only
J = no adjust

Buzz, I'll fax you the US pages later today but it's probably the UK ones you actually need.

HTH - Gio

 

[Gio]

OK, I found the UK Manual http://www.300zx-twinturbo.com/cgi-bin/manual.cgi and looked at the suspension sections. Mike is precisely right about this. From reading of the manual, it appears that the ONLY reason for this arrangement is to stiffen the rear suspension when you are parked. Seems a little pointless to me but there you go.

Mike - the UK manual gives the figures for damping force "Firm" and "Soft". Does anyone know what the figures are for the non-adjustable Japanese ones?

Confused of Colnbrook - Gio

 

[buzz]

thanks gio.
received fax today. it confirms my thoughts ontheoperation from my past weekends experimenting.
just to find a little time now to fit an independant switch to set shockstowhere i want them.
thanks for all responses.

 

[buzz]

by the way gio,
i used to live in london for nearly 10 years and there was a chap who used to work wit me called chris davis. he lived in colnbrook too. is he by any chance a neighbour of yours???
buzz

 

[Gio]

Haven't come across him yet - but then we are relative newbies to Colnbrook <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=''>