E30 5-stud conversion - reasons...?

[gjm 3258]

I've read the benefits of a 5-stud/bolt conversion are the wider range of rims available, and the ability to run bigger brakes.

On the rim front, it'd be cheaper to take your chosen rims, have them professionally welded and redrilled, so perhaps that's less of a reason.

Brakes may be another matter. Let's assume (yeah - OK - I have an idea) you could fit your chosen larger rims anyway, and could get adapter plates manufactured for suitable larger calipers. Would this negate the second reason for a 5-stud conversion? Or is there something inherent on a 4-stud hub that prevents the use of (say) 330mm vented discs?

I appreciate there are cert requirements to be met.

I have an opportunity to go either way, and with the front is a possibly new way. It's now a cost/benefits/usability exercise.

[WYZEUP 283]

Alot of people change for the ease of suspension upgrade instead of having to weld, and the option of bolt on either e46 330i or e36 m3 front brake setups. But if its just for wheel options you can get a spindle adapter to bolt 5 stud hubs on

www.epytec.de/radnaben-sonderumbau-und-zubehoer/4443/bmw-e30-radnaben-umbau-lochkreis-5x120-e36-e46-lochkreisadapter-vorderachse-5-loch-radnabe?c=1852

[gjm 3258]

If I do a suspension upgrade (which is probable), it'll likely be to something other than stock E30 parts. I've no qualms about making arrangements for the struts to accept a M3-style anti-roll bar.

The question is brakes. I don't need an 'ultimate' set up - pretty much no-one does unless they are really racing. E30s have good brakes from the factory.

I do have an E30 rear disc set up to fit to a 318i (which came with drums as stock).

Am I going to unduly compromise my brake options by staying with a 4-stud hub? (Albeit probably with a spacer/adapter...) I was considering the WMS setup from the UK, but have access to some lightweight 4-pots and can manufacture mounting brackets. The issue may be discs... Almost all problems can be got around using bells and rotors, but again there is a cost implication.

I think there are some bearing differences too, between the 4-stud and 5-stud hubs, but don't recall what they are.

[E30-323ti 66]

The E36 Wheel Bearing are much larger than the E30's.

The Struct / Kunckle connection is also much stiffer than the E30 1pc as it is not legal in NZ to weld any stiffeners to the cast parts, also BMW went back to the E36 style strut connection for the Z4M's (stiffer than the E46 knuckles).

With the E36 setup you can fit factory (front) brakes from the 320's 286x22 upto the 345x28 used on the E46 M3 CSL.

It seems these days you can even use Z4 rear drive flanges (5lug) to keep the E30'esque wheel offsets and use the E36/46 Rear Rotors (with caliper adapters).

Just don't skimp on the (E36 M3 Evo) parts needed to do the front end swap properly.

[gjm 3258]

I've been hunting for details on the 5-stud conversion. It has to be one of the most popular changes people make to an E30, and it's been done many times.

The problem I've found is that there are so many 'guides' and 'how-tos' that finding a single, truly definitive guide encapsulating the benefits, procedures and parts needed is more difficult than I'd anticipated.

I'll dig deeper/better when I have time.

[_ethrty-Andy_ 2136]

i agree, finding a guid has been tough, i have done hours and hours of research over the past month.

E36 compact rear end including Calipers. easy.

Front needs to be either all E30 M3 setup, OR:

• E36 M3 evo (1995+) - arms, offset bushes, hubs, shock assembly
• E36 any - wheel bearings and hubs (all the same part number)
• E30 51mm or E36 springs
• E30 Top hat, some will also fit the E90 upper spring purch which drops the car a little bit more.
• E36 M3 or E46 330i calipers and disks.

I am having some custom made coilovers done which are essentailly the E36 M3 unit with an E30 top hat, if you are spending all this money and has to be certed any way, might as well go adjustable coilovers as well imho.

some cheap skates will use other parts or non-M parts like non-m e36 hubs, e46 arms, e36 upper mounts etc which all messes with suspension geometry. just because something bolts up doesnt mean its right, flat peaks dont seem to understand this what effects track width and caster etc have on a car and wonder why an E30 on stock suspension can out handle thier setup.

hope this helps

[_ethrty-Andy_ 2136]

also, FYI (might be off topic) Brad from here in wellington is making up some adaptors for those people that soley want bigger brakes, if i remember right they use E34 540 calipers in the front and Audi TT disks. you then bolt on E36 compact rear disks/calipers which are already much bigger than the stock E30 parts.

[WYZEUP 283]

Yup andy has nailed it on the head.....definetly use the m3 hubs to centre the wheel properly, then means you can use m3 brakes, if you use e36 hubs you cant use the m3 brakes.

Edited June 2, 2016 by WYZEUP

[E30 325i Rag-Top 2963]

Benefits come also from the later suspension set-up of the E36 / E46 rather than just the bolt pattern. Much wider availability of coil-overs, shocks, etc, no need to weld struts.

Other benefits you have mentioned, yes you can weld and drill some but not all rims (also cost). Yes you can use top hats and remove able rotors but off-the shelf are easier and much cheaper.

If you are running bigger rims / tyres then a bigger and stronger wheel-bearing and spindle to match is a good idea.

With the scarcity of E30 M3 suspension parts the prices are in the moon beams area now and not going to come down if something breaks later on, so I would suggest the other options.

[gjm 3258]

OK...
May have found a cheaper way to do a 5-stud conversion. Of course, there have been lots of those!
E36 front hubs, Z4 rear hubs. Retain other E30 parts. Bit more to it than that of course, but that's the gist. Keeps stock geometry, too.