Sway bar question

[Blau]

So the front sway bar on a 128i is 26.5mm.
The upgrade path seems to be for the M3 sway bar, which if I look on realoem, is also 26.5.

The parts have different numbers. Is 26.5, 26.5 or is there some other magic baked into the M3 sway bar?

Any help is appreciated.

[spidertri]

The comparison that Turner wrote up years ago is pretty good at showing the difference.

https://www.turnermotorsport.com/t-t...-e92-sway-bars

Stock 128 bar is reduced diameter in the middle while the E92 M3 bar stays 26.5mm the whole way across.

[Blau]

Originally Posted by spidertri

The comparison that Turner wrote up years ago is pretty good at showing the difference.

https://www.turnermotorsport.com/t-t...-e92-sway-bars

Stock 128 bar is reduced diameter in the middle while the E92 M3 bar stays 26.5mm the whole way across.

Can't believe I missed this. Thank you!

I'm about to pull the trigger on installing the 15mm rear bar but I think I'll wait till I get the M3 FSB.

[gjm120]

Originally Posted by WeShallCallHerBlau

Can't believe I missed this. Thank you!

I'm about to pull the trigger on installing the 15mm rear bar but I think I'll wait till I get the M3 FSB.

...and the 135i front arb is tapered for about 5" less than the non sport 128i bar.

[ShocknAwe]

My recs:

Save sway bar tuning until after springs/dampers.

Don't increase rear bar size over front until a LSD is fitted. And then only if you're understeering despite allowing adequate body roll and adequate negative camber.

Have fun!

[Blau]

Originally Posted by ShocknAwe

My recs:

Save sway bar tuning until after springs/dampers.

Don't increase rear bar size over front until a LSD is fitted. And then only if you're understeering despite allowing adequate body roll and adequate negative camber.

Have fun!

Thanks man. Right now I'm just acquiring parts. I'd like to take a weekend to go front/rear sway bars, rear subframe inserts, engine and trans mounts, and coilovers.

I'm thinking I'll go with the ST X setup unless I decide to go with ISC or BC Racing. KW is out of my price range and I don't think I need to stretch my range. Car gets very little winter use so ST seems fine.

[Olgeezer1]

Front bar size depends on which M3 bar you're looking at . The E93 (convertible) bar is 28mm. Did that some years ago and added the 15mm. rear bar , along with a few other things, after installing a Wavetrac diff. last year.

[Blau]

Originally Posted by Olgeezer1

Front bar size depends on which M3 bar you're looking at . The E93 (convertible) bar is 28mm. Did that some years ago and added the 15mm. rear bar , along with a few other things, after installing a Wavetrac diff. last year.

Well, how's it all feel? Nice set up, man.

[Papa Popov]

Quick note for anyone swapping in an E93 bar - make sure you get the E93-specific bushings. They're different than the E90/E92 bushings.

[HP Autosport]

Originally Posted by WeShallCallHerBlau

So the front sway bar on a 128i is 26.5mm.
The upgrade path seems to be for the M3 sway bar, which if I look on realoem, is also 26.5.

The parts have different numbers. Is 26.5, 26.5 or is there some other magic baked into the M3 sway bar?

Any help is appreciated.

Keep in mind that larger bars will require more damping. Unless you have adjustable dampers you should upgrade the dampers first. Better yet, get a proper coilovers and just skip the bars altogether.

[Blau]

[QUOTE=HP Autosport;29157810]Keep in mind that larger bars will require more damping. Unless you have adjustable dampers you should upgrade the dampers first. Better yet, get a proper coilovers and just skip the bars altogether.


I've read this elsewhere. Coilovers coming next week along with Whiteline subframe inserts. I've already got the rear bar in 15mm but may hold off until I see how the car feels without it and I get the larger front bar.
Thx for the tips!

[HP Autosport]

[QUOTE=WeShallCallHerBlau;29158783]

Originally Posted by HP Autosport

Keep in mind that larger bars will require more damping. Unless you have adjustable dampers you should upgrade the dampers first. Better yet, get a proper coilovers and just skip the bars altogether.


I've read this elsewhere. Coilovers coming next week along with Whiteline subframe inserts. I've already got the rear bar in 15mm but may hold off until I see how the car feels without it and I get the larger front bar.
Thx for the tips!

Which coilover did you pick up?

if you plan to add a rear bar, add a good LSD first.

PM if me with any questions you may have. We have Wavetrac and Quaife.

[ShocknAwe]

Originally Posted by HP Autosport

Keep in mind that larger bars will require more damping. Unless you have adjustable dampers you should upgrade the dampers first. Better yet, get a proper coilovers and just skip the bars altogether.

Pretty much this IMO.

[Olgeezer1]

Originally Posted by WeShallCallHerBlau

Well, how's it all feel? Nice set up, man.

Feels just right to me. Very neutral to slight oversteer, just how I like it. Great acceleration out of corners. Subframe bushings done at the same time. On relatively narrow tires (225/40/18 square, 4S Mich.) that I prefer for the street . Rear is much more lively, have to turn TC off to enjoy tight corners without interference.

[Papa Popov]

Originally Posted by Papa Popov

Quick note for anyone swapping in an E93 bar - make sure you get the E93-specific bushings. They're different than the E90/E92 bushings.

To add to this for anyone else doing the swap and struggling with the bushings, a bit of dish soap works wonders for getting the things into place. From the (limited) info I found you aren't supposed to lube these bushings, but a couple drops of dawn and some elbow grease had 'er done in a jiffy and the stuff will be dry by morning.