Jump to content


Photo

The Z31 Project - Race Car


  • Please log in to reply
140 replies to this topic

#61 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 29 January 2017 - 05:27 PM

Onto the hard bit now, complete rear suspension revision where few (any?) have gone. The semi trailing arm setup is being converted to a trailing arm with lateral links system eg Gp C Bluebird, E36 BMW. The original sub frame is gone, the diff has been solidly mounted to the body, the inner legs have been cut off the suspension arms and two lateral links will run from the outer hub assemblies to a new rear diff mount setup. Lining everything up accurately and designing solutions are the tough bits, I'll let the pics do the progress talking.

 

 

 

 

Attached Thumbnails

  • DSCN0354.JPG
  • DSCN0355.JPG
  • DSCN0356.JPG
  • DSCN0357.JPG
  • DSCN0358.JPG

  • d3c0y likes this

#62 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 01 February 2017 - 05:20 PM

More progress despite much heat in the shed, ventilation might be an idea. As far as I can estimate/measure the left trailing link rod end bearing is now correctly aligned and in place, finishing work to come after the right side one has been done. The idea is to do a reverse replicate of the left one, that will be 'interesting'.

 

Now to the two lateral links, need to do them next for the left side to make sure as far as possible that the trailing link is where it should be. Rotated pic from the rear shows a rough mock up of what will be involved, hub is on the far left, diff on the far right of the pic.

 

 

 

Attached Thumbnails

  • DSCN0359.JPG
  • DSCN0360.JPG
  • DSCN0361.JPG


#63 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 08 February 2017 - 05:25 PM

Pretty well worked out the applicable theory and the resulting fabrication to the extent that it can all be measured up to put it through the simulator. Pics show the lateral link adjustment options, the upper link length will be finalised once the simulator process is completed. Going to take my time with this, so far it's looking very promising but the devil is in the detail. The link shown in the pics is just a dummy, it's alignment is such that the rear roll centre should be somewhere around the 100mm target.

 

 

DSCN0363.JPG DSCN0364.JPG

 

 



#64 d3c0y

d3c0y

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,847 posts
  • Website:http://garagesanmaru.com
  • Location:Brisbane
  • Tagline:Forum Jerk

Posted 09 February 2017 - 01:55 PM

So much time... funny to see those CVs in their original home.



#65 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 10 February 2017 - 05:16 PM

Hope this build is of interest to those who can't help themselves and have to modify car things, some of what is being done is applicable to S30's although S30 blokes seem more fixated on weight than body stiffness. Talking of weight, 1.5kg for the transmission tunnel brace pictured below.

 

 

Attached Thumbnails

  • DSCN0365.JPG


#66 d3c0y

d3c0y

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,847 posts
  • Website:http://garagesanmaru.com
  • Location:Brisbane
  • Tagline:Forum Jerk

Posted 13 February 2017 - 09:37 AM

I'm keen on doing chassis bracing on my car, however i'm kind of at the point where i'm in get it done mode. It seems like a waste to not do it now, while it's apart but I guess there is always room for future development.

 

There is a crossmember under there for the diff already, how much extra stiffness will this achieve and are you going to tie it into the rear diff mounts? Wouldnt it be more effective on the sides of the chassis rail and give you more ground clearence?



#67 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 13 February 2017 - 10:45 AM

The heavy rubbish rear suspension X member is gone as part of the change in suspension type although stock it was soft mounted. Where the rear part of the new brace mounts there was a OE excuse for a brace so there were two M8 captive nuts each side which was handy, for the front two M6 captive nuts were drilled and tapped to M8.

 

Yes, I understand the urge to get yours on the tarmac, should be a real goer. One thing I guess that is going to be done with yours is to make a rear gearbox mount that acts as a brace there. With my FJ20 donked 260 I was able to fit a single SST brace across through the gearbox to engine gap, that's where a S30 badly needs bracing I reckon.



#68 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 17 February 2017 - 07:17 PM

Everyone wants to know what's happening, too many Z31 fanboys, stop nagging  ;)

 

Seriously, time has been spent running various rear suspension options through a simulator which is an interesting exercise in frustration and compromise. Because there are competing factors like roll camber on inside and outside wheels, roll centre and ride height. Plus the mundane matter of being able to fit the necessary fabrication in the space available without interference.

 

The result of all the various trial simulations is that the one selected provides that in roll, using a static -2.5* camber, outside camber will basically remain the same within the usual race car parameters ie camber gain will keep up with roll. Inside camber gains a bit much but that's part of the balancing act, roll centre varies from 170mm static down to 136 at the extreme roll figure of -5.8*. Which is good because the lower the roll centre the less chance of a jacking effect which can in extreme situations lead to a roll over but it may be a problem when it comes to settling on what to use at the front. It will at static have a lower roll centre, if under roll it does not keep up with the rear roll then it may result in front understeer. Which may not be a bad thing, a bit of initial oversteer to get turn in and some safety understeer when body roll starts to get a bit much.

 

Now it's back to fabrication oh joy oh joy.


Edited by 260DET, 18 February 2017 - 08:00 AM.


#69 d3c0y

d3c0y

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,847 posts
  • Website:http://garagesanmaru.com
  • Location:Brisbane
  • Tagline:Forum Jerk

Posted 18 February 2017 - 08:52 AM

Come on rookie, you know we want pictures of these simulations. Words are so 1991.



#70 dat2kman

dat2kman

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 4,029 posts
  • Location:Newport Waters Qld
  • Tagline:going sailing, see ya later!

Posted 18 February 2017 - 04:50 PM

No, i dont think there are all that many z31 boyfriends out there, dont seem to be many that are nagging, or was that gagging!

#71 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 18 February 2017 - 05:39 PM

For the fanboys, including Jason, here we show The Chosen One :) What has to be done with the simulator is manually select each roll value and then note the changes. For this one 12 various roll values were input ranging from static to -5.8*, at that point negative camber had increased from 2.5 to 3.2* which is good, not that I'd want to roll that far to see what happened. In the usual range the camber stayed around 2.5. This rear suspension will have some dynamic toe in too and the trailing arm front pivot height has been adjusted to reduce the effect of anti squat.

 

 

Attached Thumbnails

  • simulator 2 slash 7.png

  • d3c0y likes this

#72 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 19 February 2017 - 09:46 AM

Have a look at this video and see how the inside rear tyre in a corner unloads by going into more negative camber. Apparently this is a good thing for any rear drive car as it helps the outside tyre drive the car around a corner, I have heard of this before but never seen it so graphically demonstrated, nearly half the wide tyre is off the deck at times. So this qualifies what I said earlier about the project's chosen setup, gaining inside wheel negative camber is a good thing.

 


Edited by 260DET, 19 February 2017 - 09:48 AM.

  • d3c0y likes this

#73 d3c0y

d3c0y

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,847 posts
  • Website:http://garagesanmaru.com
  • Location:Brisbane
  • Tagline:Forum Jerk

Posted 19 February 2017 - 06:58 PM

Either way that is a fantastic video. I love it at the start where the camera basically goes inside the tailpipe of the car in front. How does one acquire this software so i can put my zed geometry through it just for fun?

 

I've never thought of the resultant effects of body roll in this way and is very interesting.

 

With my FJ20 donked 260 I was able to fit a single SST brace across through the gearbox to engine gap, that's where a S30 badly needs bracing I reckon.

 

Do you have a pick of this i'm not following.


Edited by d3c0y, 19 February 2017 - 07:05 PM.


#74 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 20 February 2017 - 07:20 AM

Yeh it's a brilliant video, on the inside rear wheel thing I've also heard that negative camber in roll there causes the tyre to drag which acts as a brake on the inside wheel so helping the rear end to pivot round a corner. PM about the brace.

 

EDIT The simulator is here http://www.racingaspirations.com/ To get the full service requires a subscription of a few dollars per month, I'm going to cancel mine when it's finished with.


Edited by 260DET, 20 February 2017 - 12:36 PM.

  • d3c0y likes this

#75 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 07 March 2017 - 07:36 PM

doppelganger


Edited by 260DET, 08 March 2017 - 07:38 AM.


#76 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 07 March 2017 - 07:36 PM

The hardest part is done, I now have a left and a right trailing arm finished. They are set up to accept two lateral links and a coilover each side all rod ended, even the coilover botton end. Work has started on chassis brackets to accept the inner lateral links ends, have some nice swaged aluminium radius rods made for speed cars of some sort which are getting modded as suitable lateral links, with L and R threaded rod ends it's all adjustable by simply rotating the links. 

 

Could go on about the numerous design changes, fabricated parts that didn't work out, the difficulty in getting both sides the same but pfft, I know what the fans want, pics!!!!

 

DSCN0371.JPG DSCN0372.JPG

 

 

 

 


Edited by 260DET, 08 March 2017 - 07:41 AM.


#77 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 09 March 2017 - 07:53 AM

Wheels, what a PITA. Anyway have ordered a set of 18x10's, that size dictated by the biggest 18" 275/35 Hankook semi slicks available. After a lot of research I decided on Koya's because they custom fit them to your offset etc requirements, they are light and well priced. Fit at the back should be OK with a bit of guard rolling, the front may take a bit more work than that.

 

Pic is of the MCA race car.

 

 

Attached Thumbnails

  • koya sf03.jpg


#78 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 24 March 2017 - 05:56 PM

Paul Newman driving, 2+2's were also raced when the longer wheelbase was an advantage. Stock Z31's may look and drive pretty ordinary but there is no arguing with the race versions. 80's cool to the max.

Attached Thumbnails

  • Z31 racer.jpg

  • d3c0y likes this

#79 260DET

260DET

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,150 posts
  • Location:Warwick
  • Tagline:Tribal Elder

Posted 01 April 2017 - 10:32 PM

Lots of little things being done, sooner or later they will all be able to be put together to make something complete and picture worthy. In the meantime pic of a 2+2 race car, the longer wheelbase was an advantage on most circuits. Should mine use the same colour scheme?

 

z31 race 2+2.jpg

 



#80 d3c0y

d3c0y

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,847 posts
  • Website:http://garagesanmaru.com
  • Location:Brisbane
  • Tagline:Forum Jerk

Posted 02 April 2017 - 02:01 PM

The 2+2 will always be uglier though... I think definitely go with the retro race theme.

This '86 Paul Neuman scheme is my favourite:
220px-Racing300ZX.jpg






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users