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Z Cars rear suspension
http://www.gtmdrivers.com/forum/z-cars-rear-suspension-t3635-180.html
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Author:  Jaykart1227 [ Tue Jul 02, 2019 8:01 pm ]
Post subject:  Re: Z Cars rear suspension

I know they are an imperial size and the bolt hole is 1/2". I can measure the threaded part for you at the weekend if required.

Author:  Spider [ Thu Jul 04, 2019 4:14 am ]
Post subject:  Re: Z Cars rear suspension

Thanks Jaykart. They might be 1/2" x 5/8".

Author:  PhilTheGeek [ Sat Jul 06, 2019 10:02 pm ]
Post subject:  Re: Z Cars rear suspension

I've had a look at my spares this evening and they're definitely 1/2" bore and 5/8"UNF.

Author:  Spider [ Sun Jul 07, 2019 10:56 pm ]
Post subject:  Re: Z Cars rear suspension

Thanks Phil and Jaykart.

I am designing a rear suspension for my Spider based on the Z Cars system. It will be semi trailing for some camber gain and higher roll centre.

Author:  sanzomat [ Mon Jul 08, 2019 7:17 am ]
Post subject:  Re: Z Cars rear suspension

Spider wrote:
Thanks Phil and Jaykart.

I am designing a rear suspension for my Spider based on the Z Cars system. It will be semi trailing for some camber gain and higher roll centre.


If you feel like making more than one I might be interested (obviously cost dependant). Z cars style with camber gain and higher roll centre seems like the holy grail!

Author:  Spider [ Mon Jul 08, 2019 11:06 pm ]
Post subject:  Re: Z Cars rear suspension

sanzomat wrote:
Spider wrote:
Thanks Phil and Jaykart.

I am designing a rear suspension for my Spider based on the Z Cars system. It will be semi trailing for some camber gain and higher roll centre.


If you feel like making more than one I might be interested (obviously cost dependant). Z cars style with camber gain and higher roll centre seems like the holy grail!
It probably wouldn't be cost effective to build and ship from Australia and there will be some aspects (eg engine mount for my Toyota engine and steady bars for Rover engines) that won't transfer. However I am designing in Solidworks and will happily share the plans when finished.

Author:  sanzomat [ Tue Jul 09, 2019 7:26 am ]
Post subject:  Re: Z Cars rear suspension

I'd love to see the plans when you've done them. Solidworks imports into .dwg doesn't it? I don't think my fabrication skills are up to the task but I know man who can!

Hope the design goes well.

Author:  Spider [ Thu Jul 11, 2019 1:23 am ]
Post subject:  Re: Z Cars rear suspension

Yeah Sanzomat, I can easy convert all the drawings to pdf or dwg, sheet metal profiles to dxf (for laser or water-jet cutting).

This is what it looks like so far. In plan view the pivot axis is 10 degrees to the axle line. In front view it is 2 degrees, rising towards car centreline. (That's with 2 deg negative camber. Axis inclination is 3 deg with 1 deg camber, 4 deg with 0 camber etc). It uses the Ford eccentric bolt adjusters (from late Libra/Spyder rear suspension) for camber adjustment and extending the rod-ends for toe (same as Z Cars).

Image

Rover 100 and MGF are not common cars in Australia so the only way I can get parts to measure is to dismantle my car (which I will do when I get a bit closer). In the meantime, if anyone has a CV and/or a drive flange sitting around, could they check the measurements (Numbered 1-12 and A-I) on the drawings below? Some of them I know to be accurate and some are just a guess. I don't need super accurate numbers - within 0.5mm would help.

Image

Author:  Jaykart1227 [ Sun Jul 14, 2019 11:43 am ]
Post subject:  Re: Z Cars rear suspension

This looks great and having a slightly higher toll centre will be a good thing certainly. One thing I’d suggest is to make the outer rose joint length adjustable via a sleeve or some such (similar to the original MK1 adjustment on one of the track rod ends)......adjusting the toe via removing the arm and winding in and out nearly drove me insane :D

Author:  Spider [ Mon Jul 15, 2019 3:34 am ]
Post subject:  Re: Z Cars rear suspension

Thanks for that suggestion Jaykart. I will go back to an earlier plan where one of the eccentric bolts adjusts camber and the other adjusts toe. I am a bit nervous about that because it only allows plus or minus 1.25 degrees of camber adjustment. That's plenty provided the welded assembly is accurate within say plus or minus 0.5 degree.

Author:  sanzomat [ Tue Jul 16, 2019 8:58 am ]
Post subject:  Re: Z Cars rear suspension

Jaykart1227 wrote:
adjusting the toe via removing the arm and winding in and out nearly drove me insane :D

If the bracket on the tub has a space wider than the largest dimension of the rose joint eye end wouldn't it be possible to adjust it by removing the bolt and spacers and rotating the rose joint then putting back the spacers and bolt? No need to rotate the whole arm? or am I missing something?

Author:  Jaykart1227 [ Tue Jul 16, 2019 10:52 pm ]
Post subject:  Re: Z Cars rear suspension

sanzomat wrote:
Jaykart1227 wrote:
adjusting the toe via removing the arm and winding in and out nearly drove me insane :D

If the bracket on the tub has a space wider than the largest dimension of the rose joint eye end wouldn't it be possible to adjust it by removing the bolt and spacers and rotating the rose joint then putting back the spacers and bolt? No need to rotate the whole arm? or am I missing something?


In theory that should be possible if the joints sat dead centre in the brackets.....unfortunately, in reality, the joints are very close to the side of the brackets in order to get the correct track width so you can’t. I had to take both bolts out every time, pull the arm out, make a turn on the joint, bolt the arm back in, drop the car down, roll it back and forth to settle the suspension, set up my tracking brackets and string lines (and you can’t measure from the spindle ends as this moves every time you adjust the toe on the arm, you have to set your string from the inner joint position), make a measurement.......and then invariably find that you’ve got to go a bit more so rinse and repeat :roll: It really is a massive pain in the arse!

Once set it shouldn’t move though. If I was making a version of this again I would insist on the outer joint being sleeve adjustable to avoid all the faffing about and to ensure that you could get the toe absolutely spot on easily. It’s something I may have Dave at TD look into modifying in the future but for now I’m happy it’s set right. I would definitely think twice about playing with toe settings though so making it easier to adjust would be high on the agenda for me if doing it again.

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