Modifying Z3M rear to run lower offset wheels

[rneedham1979]

Gents,

I've been brainstorming trying to figure out options to reduce the width of the Z3M rear in order to run lower offset wheels. My set up won't be here until Saturday but, I'm almost 100% certain I want to run the E38 style 5's. As of right now, I plan on having the rear wheels widened to 9.5-10" depending on clearance. I need to run a big tire so... we'll see.

Anyways, I've been thinking about ways to modify the hub/trailing arm. So far, I'm thinking of two options. Whatcha guys think?

1.) Relocate the trailing arm attachment points .5-.75 inboard. This should the entire assembly to move inward and be small enough to not require modifying the half-shaft. Even if I'm forced to modify the half-shafts, I could cut, sleeve and weld them, then have them rebalanced. (most favorable)

2.) Machine the inboard side of the hub in order to position the closer to the halfshafts. This looks quite a bit more in-depth. It would require modification to the hub, rotor, caliper carrier etc. Honestly, might not even be possible.

3.) NO F-ing idea...

Any ideas gents?

[e30time]

I was looking to do the same thing, so interested to see what response you get. Ultimately, I found a different wheel combo that I like, and went that route.

[MR 325]

I'm sorry but both of those plans seem outrageous.

I don't know why you're so dead set on the E38 Style 5 but if you want to run big rubber out back you can NOT run those wheels. That's just the way it is. Buy something with the correct offset and a 245 will be no issue. If you need more than that, time for flares.

[nrubenstein]

Adding a couple inches to the inside of the barrel is going to increase the shit out of you offset anyway. By the time you are done, I wouldn't be surprised if you needed spacers to keep off the inner fender well.

[rneedham1979]

Not sure why it's outrageous... No more outrageous than an 800whp E30, no? All the higher offset wheels are hideous or in 17". I can't run 17"s because there really aren't any good tires in 17". I need more sidewall, like 50 series or more.

There is a reason why and ill figure it out.

Thanks,
Ryan

I'm sorry but both of those plans seem outrageous.

I don't know why you're so dead set on the E38 Style 5 but if you want to run big rubber out back you can NOT run those wheels. That's just the way it is. Buy something with the correct offset and a 245 will be no issue. If you need more than that, time for flares.

[rkettner]

If my 5 lug swap had 800 hp i would not care what the wheels looked like.

Having said that you should probably buy some three piece wheels, extra barrels and lips to find a combo that works for you. That might be expensive but far less of a hassle than messing with what you've mentioned above.

Can the bmw diffs and half shafts take regular abuse like that? I'd almost scrap that and fit a domestic solution if you go the full mod route.

[E30-323ti]

I'd bolt it all together as is.

245/45R16 (RA1 say) on a 16x8 et23 with M-coupe TA's should be pretty close to a good fit IMO.

Going much taller of a tyre than that, the offset won't be your problem, unless you are planning an uber rake stance on solid blocks.

[rneedham1979]

Can the bmw diffs and half shafts take regular abuse like that? I'd almost scrap that and fit a domestic solution if you go the full mod route.

I drive the car just about everyday so, looks are kind of important to me. I have looked into the 3 piece options and honestly, I may go that route in the future. We'll see how the 16x8 fit.

And yes, the Mcoupe stuff can take it fine. It really wont ever see 800whp. The stock E30 stuff held 650whp fine for a while. It only would break at the track, and I drove/beat the car daily. Never broke a driveshaft, diff or halfshaft on the street, however, I have broken a few half-shafts at the track... The Mcoupe stuff is much stronger.

[rneedham1979]

I'd bolt it all together as is.

245/45R16 (RA1 say) on a 16x8 et23 with M-coupe TA's should be pretty close to a good fit IMO.

Going much taller of a tyre than that, the offset won't be your problem, unless you are planning an uber rake stance on solid blocks.

I could and may try it first. RA1's won't do much... I need an actual DOT slick or aggressive drag radial. I may run a 245 radial on the street and get a 15" style 5, widen it and fit a tall sidewall drag radial.

All the parts will be here Saturday so, I'll have a better idea of what I'm looking at.

[rneedham1979]

If you need more than that, time for flares.

M3 fender flares may be going on this winter...