Will an E46 M3 front swaybar fit my E85 Z4?

[lewisracing]

I just bought a 2003 Z4 3.0i Sport 1 week ago with 86,000 miles. It has a shimmy in the front suspension, so I am going to pull the entire front suspension apart and try to replace anything that is worn... while I am at it, I will be replacing the swaybar bushings, so I figured now is the time to consider an upgrage to something better.

Seems from google searches that the stock Z4 bar is 24-25mm and the M3's is 27 so I will get a mild upgrade and not too much overkill. On ebay, I can get one in Cali for $65 shipped. From some searching, it seems that people talk about this upgrade, but I have yet to see a post that confirms it can be done.

Please keep in mind that I am doing budget upgrades and never going to track this car, just looking for small upgrades here and there. I am not interested in $200+ aftermarket swaybars.

So, any know for sure if it fits? Help is appreciated.

[seank]

I do not know about your car, but supposedly there are e46 m3 bars that do fit the z4m. It depends on the manufacturer.

[Kgolf31]

Only way you'll find out is trying it yourself. I'd contact TCKline Racing. They're awesome.

They helped me find a sway bar that fits my car.

[Incompatible]

I do not have first hand knowledge, but from following various threads over the years my understanding is that M bars of any model will not fit.

[lewisracing]

Thanks everyone, your responses are appreciated. Today, I took my tires to my local shop to be put on my new CSL wheels and they found that the front left tire had a huge bubble, so that would explain the shimmy. I also found that the front left swaybar bushing is completely worn out, as in there is a 1/4" gap on the top of it, appears to be possibly caused by the blown out tire causing vibration and wearing down the swaybar bushing over time via vibration. I can't believe the prior owners of this car didnt ever bother to diagnose or fix this shimmy, crazy!

I also compared the shape of the stock Z4 swaybar and it looks close in shape to the E46 M3 swaybar. So, I think I will take the advice of Kgolf31 and just attempt to install it to see if it fits. Maybe I will be the 1st person to attempt this, and if successful to report it as well… we’ll see. It’s only $69.

For anyone local to LA area, Pacific Tire Motorsports in North Redondo is awesome. I have been there 3 times in the past, they always help me out, really nice guys and they will do stuff that most other shops won't bother with. I am truely impressed!

[lewisracing]

Comparing an H&R swaybar (top photo), vs. a junkyard E46 M3 swaybar (bottom photo) on Ebay for $60.

[lewisracing]

Ok boys and girls, for $60 I bought an E46 M3 Vert rollbar on eBay, shipped. Another $45 I got poly bushings. Turns out they fit! I'll post pics later. Great project for $105!

[Incompatible]

Originally Posted by lewisracing

Ok boys and girls, for $60 I bought an E46 M3 Vert rollbar on eBay, shipped. Another $45 I got poly bushings. Turns out they fit! I'll post pics later. Great project for $105!

OK...Good to know, something to put in the Z4 reference file.

....3.0si Std....Sport......H&R......Dinan......Z4M......E46 M3
F......24..........25..........27.........25...... ...27..........27
R......18..........19..........21.........22...... ..22.5........

Any plans for the rear?

[lewisracing]

No plans for the rear yet. I was told that the rear swaybar is completely different.

[lewisracing]

OK, so here are photos of the 24mm stock Z4 bar (on the bottom, with more curves and with the brackets on it) and 27mm E46 M3 Convertible bar (on the top without brackets on it). Keep in mind if you would like to do the same conversion that the regular M3 bar is 26mm, you need to get the convertible bar to get to 27mm.

It's hard to tell from the photos that the M3 bar is 3mm thicker, but it is. As for handling, I don't auto-x it, so I can't really tell the difference, but for $100, it's nice to know it's there just in case!

By the way, the Z4's stock brackets and stock end links work fine with the M3 bar. All you need is the bar and 27mm bushings. I changed it in about 50 minutes, and 15 minutes of that time was cleaning the mounts and underneath the car cause i'm anal like that.

Last photo is the E46 M3 bar installed with new poly bushings (blue) I got on Ebay: http://www.ebay.com/itm/BMW-Front-Sw...10d40b&vxp=mtr

[Incompatible]

Good info, keep it coming! I assume the small difference in bar configuration for the M3 doesn't create any interference problems with suspension travel?

[Kgolf31]

I have my Stock Z4M Bar (27mm) with bushings if anyone is interested. I'll sell it on the cheap

[lewisracing]

Originally Posted by Incompatible

Good info, keep it coming! I assume the small difference in bar configuration for the M3 doesn't create any interference problems with suspension travel?

No, I thought it would, but no problems at all. Clearances are great, close to stock.

[mpathic]

Found this old thread while researching the same question.
To go a step larger, any reason that a 30mm E46 M3 CSL bar wouldn't fit the Z4? Mine's an M with the original 27mm bar.
For the rear, all E46 and Z4 bars are the same part numbers. M3CSL 22.5 rear is same as MZ4 Coupe.

[The Shoe]

E46 M3 Black OEM Bar fits fine, I went with a Mason Engineering Truss Brace in Steel.

[AriuSen]

Just letting everyone know that today I put the m3 e46 hotchkis sway bar and they fit perfectly. No adjustment whatsoever