Z31 rear conversion

[CamInHead]

quick blag; got the brake hardware and I got a z31 beam off ebay. save for a couple of bent brackets it looks in good shape and even came with handbrake cables attached (no doubt they're borked).

I'll start a proper project thread but I'm skint after buying that porker.

[gerryb]

I'm a bit confused with this thread. This is what I have 'seen' with Z31's.

MkI 84 to late 86 - non ventilated disc on rear 290mm dia. same calipers as s12 with the exception of mounting 'ears' which are longer to accomodate 290mm dia. rotor. (NB non turbo = 4 stud till 85, all others 5 stud)


MkII early 87 to 88 ventilated rear rotors,(both turbo and non turbo are all 5 stud) can't remember exact diameter, 282mm from memory. Calipers match rotors with wider opening to suit, (not interchangeable with earlier calipers). The trailing arms have a 10mm longer "bearing tube", to push the hubs out 10mm to suit the extra 10mm of rotor width. (I have a set of these later trailing arms complete and have compared it physically and measured the differences with earlier type Z31 setup)

So in closing if you want the ventilated setup you need the whole trailing arm with rotors and calipers and swap it onto your s12.

[steves12zx]

So does this mean you can use a whole rear end setup from a Z31 turbo (they have an LSD as standard) to get the vented brake upgrade and also and LSD.

Also if the LSD is bolt in can you just use the LSD and shafts from a Z31 turbo with the S12 subframe and hubs???

[CamInHead]

I think the driveshafts would be different. Better to get the whole Z31 rear set-up but I'd expect the LSD to be fairly tired after 20-odd years.

[s13eater]

i've got hold of a z31 turbo rear subframe and trailing arms, only thing that ive noticed is that where the shafts mount to the back of the hub they are 4 bolt instead of the s12 6 bolt set up, are the shafts the same spline set up as the s12 ones ?if so i could just change the ends.

[CamInHead]

trust me Randy wanted that thing to work...
So did I.

No the Z31 sub-frame does not work. it has arc that hits the body.
the Z31 control arms Bolt up to S12 direct bolt in, brakes and all.

this is what i have and how i did my 5 lug conversion in the rear.

Here

I hope this fella is wrong as I just dropped £100+ getting my spare z31 x-member prepaired

Not really sure what he means by "it has arc that hits the body" ?

[s13eater]

Originally Posted by CamInHead

Here

I hope this fella is wrong as I just dropped £100+ getting my spare z31 x-member prepaired

Not really sure what he means by "it has arc that hits the body" ?

hi mate, to me i think he's put it in upside down, if you turn it over, then it sits higher where the diff mounts, just a wild guess though.

[CamInHead]

Originally Posted by s13eater

i've got hold of a z31 turbo rear subframe and trailing arms, only thing that ive noticed is that where the shafts mount to the back of the hub they are 4 bolt instead of the s12 6 bolt set up, are the shafts the same spline set up as the s12 ones ?if so i could just change the ends.

I've just pulled my N/S S12 half-shaft and trailing arm off and the hubs are different. Stock S12 has 6stud 3x2 but my Z31s are 4x1, same as yours. Also, the input shaft (diff end) is slightly larger and the (spider?) bearing is totally different.
So I'm a bit lost right now.

Can someone confirm a stock UK Turbo comes with the R200 diff ?

[s13eater]

Originally Posted by CamInHead

I've just pulled my N/S S12 half-shaft and trailing arm off and the hubs are different. Stock S12 has 6stud 3x2 but my Z31s are 4x1, same as yours. Also, the input shaft (diff end) is slightly larger and the (spider?) bearing is totally different.
So I'm a bit lost right now.

Can someone confirm a stock UK Turbo comes with the R200 diff ?

just measured the z31 and s12 shafts matey, they both measure 29.5mm and are 29 spline and the s12 is a r200 diff.