250 SWB (Z3 rear offset issue) Wire Wheels

Law' · #1 10th October 2016, 10:47

Hello all,

I am aware that this has been raised before and that Bill Dutton (aka Plastic Porsche) came up with the idea to switch out the std Z3 rear hubs for Z4 ones and to use the slimmer E36/E46 solid rear discs gaining 22mm more offset on each side.

Did anyone ever actually achieve this and if so would they be kind enough to share their experience please?

I'm in the middle of my build and like others before really want to fit wire wheels but don't want to risk buying all the new Z4 related parts to find out that the concept does not work.

Hope to hear from one of you guys out there - Cheers

PS - I have attached the photos originally posted by Bill in the hope of jogging a few memories!

Law' · #2 10th October 2016, 10:52

Here's Bill's original post:

Looking on all the Google sear areas and the BMWmini spares site, it appears that fitting a Z4 rear drive flange/hub will bring the rear in by approx 20mm.

The early lower powered e36/e46 3 series cars had solid rear discs which are 60.1 mm high and 280mm diameter as opposed to the z3 with 83mm high and 272mm diameter, handbrake shoes on the 3 series are same diameter but narrower, disc same machined area though.

The calliper bracket mounting bolts are a standard M10 10.9 strength shouldered bolt, 26.5mm long.

If I bought some 30mm 10.9 bolts and put a 3mm shim between the caliper bracket and the hub to centralise the bracket on the disc, and turned a 3 series disc down to 272mm diameter this set up would appear to be good to go.

This could potentially give a 40mm decrease in the rear track on the 6 cylinder wide bodied cars for not a lot of money - 2nd hand or new flanges, new wheel bearings, discs and some bolts.

Thoughts / views ?

Follow up post (by Bill):

Physical check complete, decrease = 22mm per side, disc surfaces level within 2mm of each other.

z3 drive shaft fits z4 hub

Lucky@LeMans · #3 10th October 2016, 19:00

From the various threads on this subject I think the general consensus is that you can't fit deep dish wires like those on the original 250 SWB's . Even with the mods you mention the track remains too wide.
Bolt on wires fit in the arch and the centres don't stick out unlike on the knock on wheels. The red Nubodi Kalifornia looks good with the "bolt on" wheels.

Law' · #4 11th October 2016, 04:23

Thx for the reply.

This may be a case of 'I told you so' but as I now know (confidently) that Z4 hubs fit the Z3 set up I've decided to order a few parts (Z4 hub, E36 solid rear disc & w/bearing) for one side where I will bench test the concept simply to see if it works.

In the mean time I welcome further comments / POV's; it goes without saying that I will report back on my bench test result asap.

Mister Towed · #5 11th October 2016, 06:16

If you can get Borrani style dished wires to fit it would be well worth the effort and expense imho. Dished wheels are part of the identity of a 250GT and I guess you feel the same way judging by your desire to fit them.

I really hope your Z4 mods will allow them to fit, but if you need another couple of mm, you could add a subtle flare to the rear arches for clearance.

Good luck!

http://shop.mwsint.com/product_details.asp?id=490

redratbike · #6 11th October 2016, 06:58

I'm digging the black versions

http://shop.mwsint.com/product_details.asp?id=431

Jaguartvr · #7 11th October 2016, 08:08

Not Borrani's but then again Borrani's aren't £300. Might do someone, they don't come up very often and normally get snapped up pretty quick.

http://www.ebay.co.uk/itm/15-bolt-on...kAAOSwLnBX4oxU

When I was refurbing my wire wheel set up I bought some parts from Orson equipment. They were very helpful and much cheaper than retailers. Could be worth a phone call. As I remember my Jag wheel hub at the front has
a flat back surface and just bolts on. If they make them it shouldn't be too much extra work to get the mounting plate drilled with the correct PCD. Would be great if a few people could get together for a group purchase. Second hand splined wire wheels are so much cheaper and more plentiful
than the bolt on type.
http://www.orsonequipment.co.uk/splined-hubs/

NeilF355 · #8 11th October 2016, 08:15

I prefer the stainless steel version

Jaguartvr · #9 11th October 2016, 08:24

So do I. When I bought my Jag chrome wire from MWS about 15 years ago they said you couldn't have stainless spokes and a stainless rim as it would cause the spokes to snap, so I had to go with stainless spokes and a chrome rim. Now of course they sell them as all stainless and my chrome rims have small traces of rust on all of them

NeilF355 · #10 11th October 2016, 09:06

Quote:

Originally Posted by Jaguartvr

my chrome rims have small traces of rust on all of them

I was warned about that by a mate who has the same problem with his Stainless / Chromed steel rim wheels on his Morgan which is why I went for the all stainless option.

Weirdly when I put my wheels next to a chromed steel rim wheel mine look like they have a yellowish tinge to the stainless steel as compared to the chrome. It's not at all obvious if I'm just looking at the wheel itself though, as you can see in the picture.

Jaguartvr · #11 11th October 2016, 09:09

Stainless don't have the same deep shine as chrome, but they won't rust. I have a babies bottle brush with a twisted metal handle, chop the end off so it fits in a battery drill and it slips perfectly through all of the spokes. The only way to clean wires without too much effort.

Law' · #12 11th October 2016, 11:50

Yep, they are the rims that I'm trying all of the 'old folk law' remedies to get to fit !

Barber · #13 12th October 2016, 09:10

I wouldn't describe JagTVR as "old folk" just yet.

Law' · #14 12th October 2016, 10:16

Sounds like you have misunderstood the essence of my phrase 'old folk law'. What I meant by way of this was people over the years come up with solutions to life's problems some work some do not, like 'I know a chap that once....'

Sorry if it bothered you, no offence intended!

Barber · #15 12th October 2016, 10:19

Quote:

Originally Posted by Law'

Sounds like you have misunderstood the essence of my phrase 'old folk law'. What I meant by way of this was people over the years come up with solutions to life's problems some work some do not, like 'I know a chap that once....'

Sorry if it bothered you, no offence intended!

The apologies are due from me, I deliberately misconstrued in order to pull Jag's leg.

Jaguartvr · #16 12th October 2016, 13:59

I've been called a lot worse, in fact a lot, lot worse!

Law' · #17 14th January 2017, 00:57

Quite some time has passed since I started this thread, better late than never as they say so here's an update on how I actually got on testing the idea out.

Good news, the concept of using a Z4 rear hub along with a solid rear disc off a E36/E46 BMW (as std 280mm turned down to 272mm dia.) actually works!

After completing the switch over I gained an extra 22mm on each side. Oh, you will also need a couple of new wheel bearings as you can't save the old ones when when doing this conversion.

Credit must go out to Plastic Porsche as he was the one who originally floated the idea.

Here's a few images of the end result along with a link to the a video of it all on youtube:

https://youtu.be/EzuJ4DA6wn8