Z3 1.8 gone wide, need help for wheels

[Inferno]

Hello!

I just finished widening my 1.8 1996 Z3, problem is i need new wheels now, only thing i know about my current rims is that they are 17" and made by alutec, schnitzer type 2 replica, i don't know their offset and their width.

i found a set of wheels i like they are 8.5x18" ET40 front and 9.5x18" ET40 rear, but comparing the rear rim to my current rear rim (guessing the width and the offset since i don't actually know them) in this tool: http://www.rimsntires.com/specspro.jsp i realize that i will gain only a few mm on the rear gap of the fender... can anyone help me giving me a direction on what dimensions i should look for WITHOUT the need to put spacers?? (Don't tell me Z3M alloys, i cannot find them ANYWHERE at logical price at least)

This is how my car looks like now:
http://i883.photobucket.com/albums/ac36 ... 2954b7.jpg

http://i883.photobucket.com/albums/ac36 ... fddabb.jpg

http://i883.photobucket.com/albums/ac36 ... ee53e3.jpg

http://i883.photobucket.com/albums/ac36 ... 79923c.jpg

[BladeRunner919]

If you put the

[Southernboy]

...... looks like you need a wider axle......... I think the axles you have are the original e30's....the e36 axles are longer - left / right.....

I know this from a buddy here who has an e30 race car, he recently fitted the e36 rear axles which are considerably wider...that would mean your current wheels would extend further out on the wider axle. Probably easiest to get a second hand rear axle complete off a 3 series e36 318. That way you will still have the same diff etc. You may need to check the suspension arms etc as they might be different to accommodate the wider axles.

[Inferno]

i have 2 buddies with exactly the same car that did exactly the same thing, they didn't need new axle, just the rims, why don't you ask them you will say, that's because they both used Z3M wheels plus 15mm spacers to make it look even wider, but car looks ok even without the spacers, that's because of the ET8 offset the rear rims have. that's my problem i can't find anywhere Z3m rims or aftermarket rims with such a low offset.

[Southernboy]

......... Exactly what I'm telling you... If you fit a wider axle, you don't need to use "special" wheels and such thick spacers. For sure you can use a wider wheel with an offset to push the wheel out, plus a spacer, but the benefit of a wider axle means your choice of wheels is unlimited.

[Inferno]

aha... now i get your point.

[BladeRunner919]

OT, but what exhaust do you have on the car? I see you have a twin-pipe back box.

[Inferno]

Magnaflow 14815, with z3 1.9 M44 pipe from engine to the muffler

[c_w]

Yes one option is to get the wider axle off a 2.8/3.0 or get some Z3M wheels, the latter would probably be the most sought after option since they only fit M models usually. Many people try and fit them to non-Ms only for the rears to stick out and look a bit dodgy, but your setup now is perfect for them.

[Inferno]

i found a pair of new Dare DR-RS 17x8.5 ET20 & 17x10 ET15 for a really good price, i will also pay a visit maybe today to a local "artist" who takes your rims and makes them wider, he want to see my rims and tell me if it can be done safely, any thoughts? (i don't want to change the axle, no need to spend money on that route i think)

[BladeRunner919]

Have a look at the US-based forums, where there is a lot of talk about wheel choices for Z3///M cars, which basically have the fitment that you have.

[Gazza]

i found a pair of new Dare DR-RS 17x8.5 ET20 & 17x10 ET15 for a really good price, i will also pay a visit maybe today to a local "artist" who takes your rims and makes them wider, he want to see my rims and tell me if it can be done safely, any thoughts? (i don't want to change the axle, no need to spend money on that route i think)

The 17x10 should fit the rear ok but the fronts will not work with the offset of 20, you will need something like 35-41 with a width of upto 8.5"

[Jonttt]

You have ended up with the same eternal problem of ///M owners finding alternative wheels due to the very low rear offset required.

The easiest solution is to fit e36 3 series fitment to the front and 5 series fitment to the rear. The tears will still need a c10mm spacer so you will loose dish compared to the original Z3m rears.

Schnitzer did this mix and match with supplied spacers for most of their Z3m wheels with the exception of the type II race which have the correct rear offset but are very rare.

So you need to find someone who will mix a 3 and 5 series set or wait for a Z3m owner with some very rare correct offset schnitzers or rondalls to put them up for sale

Have a read of my journal to see some of the aftermarket schnitzer, hamann and rondalls that will fit

Ps as said above et20 for the front is wayyyyyyyyyy too low.

[Inferno]

i visited a local rim shop, he advised me the best value for money deal is to put on adapters (big spacers) so i gave the order to build me 50mm spacers on each side, total axle widening 100mm, If and when the opportunity comes i will buy a set of Z3M rims which are correct for my current setup and they are my favourite rims of all.

Thank you all for you time you really are amazing guys!

[Inferno]

I 've got a new question, the spacers (pcd adaptors in my case) affects the offset not the wheel width correct? If so, if my wheel is et40 how can i calculate the new offset number after the 50mm pcd installation? Is there anyway to calculate this?

Edit: stupid question i think i got it, new offset will be -10

[Southernboy]

Please make sure the 50mm spacers are made to bolt onto the hub. The wheel can then bolt into the spacer. It is very important that the spacer be secured to the hub and not simply held there by use of longer bolts through the wheel. Also, and if possible, have them made with at least 3 "locating pins which should have reciprocal locating holes in the hub face. The importance of this is to ensure the spacers effectively become part of the hub. You must understand that under "normal" conditions, you have 2 surfaces being held together - the wheel rim against the hub - this is torqued to the correct setting for the bolts being used in an OEM situation. By fitting a spacer, you are effectively doubling the surfaces to 4 and this will mean that the bolts would need to be torqued to 4 times the OEM setting to achieve the same safety standard. By fitting the spacer with at least 3 locating studs and then bolting it to the hub, you will ensure no lateral slip between the faces of the hub / spacer join. Then the spacer will need to have the same central flange that the hub currently has to centralise and hold the wheel rim steady after it is bolted to the spacer.
I have heard of people fitting 30mm spacers with "longer" bolts which pass through the wheel rim, the spacer and bolt into the hub - there have been incidents of these bolts snapping. Also, please realise that the rear drum into which the wheel bolts, is only held onto the hub by 1 small screw - yes just 1 small screw !! you will be placing immense strain on this by moving the point of leverage 50mm outside of the head of that screw. In the OEM position, the face of the wheel rim is literally up against the head of that screw. This means you are risking the possibility of that 1 small screw being wrenched out complete with the hub / drum and the wheel.
It is important to consider the geometry of what you are doing and the safety implications - especially if you have a passenger, and without doubt the insurance factor in the event of a malfunction and accident.

[Inferno]

Everything you mentioned has been done, that's the difference between spacers and pcd adaptors, i am installing pcd adaptors, however the last thing you mentioned about 1 small screw holding the drum is a bit concerning i would say. I will definetely check it. However isn't it the same risk as installing wider rims? What's the difference?

[Southernboy]

A wider rim still has one face mating to the hub, so the shearing force is as close to the face of the hub as you can have it.
The 1 small screw is all that is required to remove to remove the rear drum so you can access the hand brake shoes. If you remove one of the rear wheels, release the hand brake, remove the screw, you can use a wood mallet and tap the drum off. So, it's just that 1 screw which holds the drum to the hub, and it's the drum into which the 5 wheel bolts are secured.

[Southernboy]

The greatest risk occurs when cornering...that's when the forces are at their most extreme. The entire weight of the rear of the car is being pushed outwards on the one wheel and inwards on the opposite side. That weight is multiplied exponentially by the speed at which you travel through the corner. If you have ever watched Formula One racing, you may have seen the lateral G forces being displayed as the car passes through a corner. The higher the speed the greater the forces.

[Inferno]

Just spoke with my mechanic (every z3 owner has to have his mechanics mobile number :p)

The one small screw just holds the drum/disc to the hub and the only purpose it has is that the drum doesn't fall when you are changing disc brakes for example, the rim or pcd or spacer or whatever, mounts via their bolts DIRECTLY to the hub beyond the drum or something like that anyway, so all the load falls onto the 5 bolts

[Southernboy]

...correct....my point is that the 5 bolts must hold the "spacer" and a further 5 bolts must secure the wheel to the "spacer" - which is what you say you are having made. So, you are certainly making the set-up as secure as possible and in the correct way.

[Inferno]

Perfect! Thanx bro!

[gookah]

the single screw is a total red herring and has nothing to do with the spacers fitment

Tut Tut Barry....

[Inferno]

is it safe to put 245/40 tyres on an 8j wheel, and what are the benefits? (front tyres will remain 225/45)

[Inferno]

Here we go











Next step is 245/40r17 on the rear axle

[Dino D]

Looks lovely, a rare site in Athens. Don't remember seeing many when I lived there.

It's a pity about the silly car tax rules there otherwise would just send you a 2.8...

Although a 1.9 must be plenty of fun sliding about on the shiny tarmac there, especially with snowy weather now...

[c_w]

I would avoid running spacers if possible.

Those Dare wheels could possible work, the rears should work well, the fronts might work depending ride height, camber and tyre choice. I run 8.5x17 ET13 on the front of mine. There is slight poke but not big issue, ET20 would be great on my car!

[Inferno]

Looks lovely, a rare site in Athens. Don't remember seeing many when I lived there.

It's a pity about the silly car tax rules there otherwise would just send you a 2.8...

Although a 1.9 must be plenty of fun sliding about on the shiny tarmac there, especially with snowy weather now...

yeah tax rules based on displacement are trully stupid!

[Inferno]

i am looking for a pair of rear trailing arms, from what i understand there was 2 different types, those with part number 33321091151-2 and those with part number 33321094761-2, second part number are some mm longer-wider.

looking at these links in the bottom i have a confusion, first trailing arms were made for 1.8 M43, 1.9 M44 AND 1.9 M43 (That's the facelift). Second trailing arms were made for all the 6cyl models (except ///M) AND AGAIN 1.9 M43. is this possible? it's really impossible to find parts from 6cyl Z3s in Greece because there where actually sold more ///Ms that simple 6cyl. So if i find (i might already have that's why i am asking) a used complete rear axle from a facelift 1.9 M43 will be the same as a 2.8 for instance of will it be the same as 1.8?

http://www.realoem.com/bmw/enUS/partxre ... &series=Z3

http://www.realoem.com/bmw/enUS/partxre ... &series=Z3

[Mugs]

i think you'll find that the 1.8 and 1.9 (4cyl) use a narrower axle to the 6 cyl models as they have narrow rear arches. the M also uses a narrower axle to accommodate the wide lip rear wheels under the wide arches. the 6 cyl use a wider rear axle under the wide arches. this applies to all pre-facelift cars although, i think, all M roadsters were pre-face shape. i'm not sure about the facelift axles as i believe all models (apart from M's) used the wide rear arches so i would assume the axles are the same but i am not entirely sure.

[Inferno]

i know that: prefacelift 4 cyl had the narrow axle, prefacelift 6 cyl had the wide axle, and all ///M had a narrow axle slightly wider than the 4 cyl cars, they balanced the gap with the massive rear fenders with the rear wheels having an ET8. question is which axle had the 4 cyl facelift cars because in real oem shows that facelifts had both narrow and wide axles?!?!

Anyway i made a turn, since the axle i mentioned earlier i found it was from a 4cyl prefacelift, i am now trying to find some Z3M wheels, but they are EXTREMELY rare to find, i found a front pair in a very very low price, the owner states they are not bented. However the price is low which makes me suspicious, do you have any tips how to check and understand the condition of the wheels?

[BladeRunner919]

Pre-facelift 4 cylinder cars had the narrower trailing arms because they had the narrower body. Post-facelift the 4 cylinder cars had the wider body and, hence, the wider trailing arms.

[Inferno]

ok, thank's. So it's a realoem mistake? They have registered the facelift 1.9 in both narrow and wide trailing arms..

[Inferno]

Just ordered some new dare dr-rs from UK, silver with golden rivets, 17"x7.5J ET30 and 17"x10J ET15 plus 20 or 25mm spacer on the rears. I'm planning to run fronts on 225/45 and the rears on 255/40 do you guys think i will have any problems on the front wheels? i am running now 17"x8J ET35 with 225/45 tyres and it looks pretty much on edge... Should i choose any other tyre combo?