5 stud swap using Z3 rear hubs, any info?

Post Thu Aug 21, 2014 1:47 pm

I'm looking into swapping to 5 stud when I M52 my e30, after a little bit of searching around the simplest solution for the rear seems to be using 6 cyl Z3 hubs. As this only requires the hubs and brakes from the z3 and you can retain the original e30 trailing arms.

Just wondered if anyone had done this? or if the 318ti trailing arm route is better?

Thanks.

Post Thu Aug 21, 2014 1:51 pm

I am sure I have posted the whole lot of the info on this somewhere, no idea where though.

In essence z3 hubs from a late wide body car or a 6 cylinder car.

e30 arms and bearings

z3 calipers, handbrake bits, back plates and discs.

As close to factory as possible.

Edit - offset info.

http://www.e30zone.net/modules.php?name ... highlight=

Post Thu Aug 21, 2014 2:56 pm

cheers mate, sounds pretty straight forward.

Ill add those to the shopping list

Post Thu Aug 21, 2014 3:08 pm

just a thought would this also work with the front hubs/bearings from the Z3??

Post Thu Aug 21, 2014 5:46 pm

I might be talking rubbish but I think that Z3's rear suspension setup is E30 based but the front is E36 based so i'm guessing the front uses a larger diameter spindle for the hub/wheel bearing than the E30.

What I'm looking at using for the front is an adapter set from a company in Lithuania, the set has an adapter that fits on the E30 spindle to allow you to use E36 front hubs and wheel bearings, and there is an adapter for mounting the calliper.

http://www.r3vlimited.com/board/showthread.php?t=306268

Post Thu Aug 21, 2014 5:55 pm

steve_k wrote:just a thought would this also work with the front hubs/bearings from the Z3??

If only.

The Z3 is a bastard mix of E30 and E36 like the compact.

However Z3 front struts may be better than E36m3 struts as the geometry will be different and the steering angles different.
Would have to measure some VERY accurately or fit some to a car to find out.

That adaptor kit is pretty much what I designed about 2 years ago but have not had the money to do anything about, there is one thing with that that I would not be happy about and that is the removal of material from the centre of the stub axle for the bolt and the gap in the sleeve.

Those two things combined mean a weaker stub axle and a high stress point close to the weakened bit.

My way around it was to use a modified deep insert nut an a hub/disc centric spacer on the hub so that the axle was untouched, the sleeve was one piece and the disc/wheel is moved out to the correct distance keeping the loadings on the parts consistent with the stock set up.

I will post some pictures later but I doubt I will get very much further with it soon unless someone wants to pay to have some machined.

Post Thu Aug 21, 2014 6:51 pm

I see what you mean but I think the amount of material you will be removing is minimal, the sale thread shows it being used on drift cars etc which will induce much higher stresses than my road car will be putting the kit under. It also says some people don't bother with that bolt, and I dont really see the point of it.

Post Thu Aug 21, 2014 8:41 pm

Is that hub/bearing held in with just that poxy machined up bolt/nut?

Post Thu Aug 21, 2014 10:13 pm

looks that way, from the for sale thread and the review thread the seller says you can either loctite it on (which is apparently what the professional drifters that use these have done), or you can tap the stub axle and use the reverse threaded bolt which is supplied.

Post Fri Aug 22, 2014 1:52 pm

It's not the peak value of the stresses it's the number of loading cycles.

It is a high cycle fatigue issue that race cars just don't have in the suspension but road cars do, it is why it has taken so long for road cars to start using as much aluminium as we use now in the suspension as a road car can put things through thousands of cycles of loading in a month.

Rose joints are a good example, a road car can hammer out a joint in months that would last 2 seasons on a race car simply because of the mileage a road car does.

Post Mon Aug 25, 2014 3:39 pm

wasnt there a kit on 300mm.de that used a sleeve to go over the e30 front stub axle so that you could convert to 5 stud easier??

Post Tue Aug 26, 2014 1:00 pm

It's been done to death like that, It all seems to hinge on how you deal with the e36 bearing being wider than the e30 stub axle.

The e30 is 31mm diameter and the e36 37mm (iirc) so a sleeve is a simple thing, what you have to then deal with is the hub nut is then not big enough to hold the bearing on properly and then sits too far out leaving only a few turns of thread engagement.