Is it worth upgrading the rear sway bar?

[BumpinAlpine]

After reading up on the E46 suspension, a lot of people on the forums mention that upgrading the rear sway bar increases understeer. I was looking at upgrading the front sway bar to the Hotchkins 30mm bar and wondering if I should just leave the rear bar alone.

[wertyu78]

After reading up on the E46 suspension, a lot of people on the forums mention that upgrading the rear sway bar increases understeer. I was looking at upgrading the front sway bar to the Hotchkins 30mm bar and wondering if I should just leave the rear bar alone.

A stiffer rear sway bar typically induces more over-steer, as the rear end of the car will rotate faster.

[johnrando]

That's what I would have thought, oversteer with a bigger rear bar, but I've read many a post that says it induces understeer.

[wertyu78]

That's what I would have thought, oversteer with a bigger rear bar, but I've read many a post that says it induces understeer.

There are likely other factors contributing to the understeer, and perhaps, even a placebo effect.

General rule of thumb - larger rear bar, less roll = faster rotation. That's physics

you just reminded me, time to upload those photos from earlier this year.

[wertyu78]

There are likely other factors contributing to the understeer, and perhaps, even a placebo effect.

General rule of thumb - larger rear bar, less roll = faster rotation. That's physics

you just reminded me, time to upload those photos from earlier this year.

If you suffer from understeer.... there are a ton of options:

add negative camber, add toe out, add positive camber, stiffen front bar, etc. etc. etc. etc.

[derbo]

30mm front bar, stock M3 rear bar. Feels awesome. :D

[BMWCurves]

30mm front bar, stock M3 rear bar. Feels awesome. :D

Don't you have to modify the M3 rear sway bar to get it to fit on our cars?

[san]

Don't you have to modify the M3 rear sway bar to get it to fit on our cars?

I think derbo has m3 rear suspension on his Zhp...


Sent from my iPhone using Tapatalk

[slater]

Don't you have to modify the M3 rear sway bar to get it to fit on our cars?

I think derbo has m3 rear suspension on his Zhp...

yep, you need the entire M3 rear subframe assembly (with diff, axles, etc) to run the M3 rear swaybar.

i just upgraded the front to a stock M3 bar (26mm) with poly bushings and have the stock rear bar on at the moment. the front turns in much nicer. i will be putting a 20mm stock rear swaybar from an E46 vert on shortly.

peter

[Simmsled]

yep, you need the entire M3 rear subframe assembly (with diff, axles, etc) to run the M3 rear swaybar.

i just upgraded the front to a stock M3 bar (26mm) with poly bushings and have the stock rear bar on at the moment. the front turns in much nicer. i will be putting a 20mm stock rear swaybar from an E46 vert on shortly.

peter

This combination, I've heard, is a great "OEM+" upgrade.

Definitely review it!