[BimmerHausPerformance]

Anyone know off the top of their head or done the research for the biggest sways front and rear that are available?

I know the M5's were 18 mm.

H&R are 20 mm I think?

I saw some 24 and 26's on someone's car on youtube but could never find them.

Anyone know? TIA.

[ChiNorm]

The H&R are 30mm front and 20mm rear and are MUCH stiffer than the M5 bars. The H&R are solid and the M5 are hollow. I tried the H&R but they are far too stiff for the bad Chicago roads. The also noticeably interfered with the independent suspension, as lots of shock from one corner was transmitted to the other.

I sold both my H&R and M5 bars and went with KW V3 and the stock bars. IMHO, a much better choice for this part of the world.

Good luck.

[ziekxq]

I am running h&r sway bars and live in Illinois too... I go to City often and didn't notice anything crazy. To me corning came much better. I think it depends on your taste. Stiffer sways would do that though.

[BimmerHausPerformance]

I'm a weekend driver, work from home, and live on top of a ridge with nothing but long sweeping curves to drive up and down every time I leave my house... Stiff will be good.

[Surly73]

Originally Posted by BrowBMW

I'm a weekend driver, work from home, and live on top of a ridge with nothing but long sweeping curves to drive up and down every time I leave my house... Stiff will be good.

As ChiNorm pointed out - it's not just stiffness to consider

I have multiple sway bars on hand. After I get my KWv3s installed I will be "retuning" my final set up and selling what I don't need.

I have the stock bars, M5 front, 650i rear, and the H&R 30/20 kit.

In terms of perception - the front bar is responsible for controlling most of the roll felt from the driver's seat. On a fully stock 2011 pre-LCI X-Drive set up, the steering wheel felt connected to "lean hydraulics" instead of turning the car. The M5 front bar took out lots of lean, but stiffening the front and not the rear increases understeer.

The 650i rear bar helped but was still not enough to balance the car. The percentage increase stock -> M5 front was still significantly greater than the stock -> 650i rear increase.

I installed the H&R 30/20. Very stiff and made the car feel smaller. Within a day I started observing the loss of independent suspension action. Turning into a driveway or entryway (one wheel before the other) could set up a left/right oscillation.

Technically, H&R says their kit isn't for X-Drive, but it physically fits fine. There may be other reasons (e.g. strength of components?) to insist that they aren't for X-Drive.

For a couple of years now I have been running M5 front, H&R 20mm rear, but I don't like how the M5 bar ends have a different angle that stresses out the front end links.

I believe I will have to reassess everything when the KWs go on in the spring. I might go back to stock. Not looking forward to swapping bars all over the place.

[BimmerHausPerformance]

Good info. However, I'm not an Xdrive. I like a stiff ride and feeling the road, more than a comfortable ride.

[Sylverlee]

Originally Posted by BrowBMW

Good info. However, I'm not an Xdrive. I like a stiff ride and feeling the road, more than a comfortable ride.

That's what I thought about myself as well, until I tried thicker sways on the F10..

[BimmerHausPerformance]

I used to daily drive an e30 m3 with a full roll cage, race seats, 5 point harness, dumped on motons, and I loved it. I think I'm willing to risk it :-)

[Unspec]

Originally Posted by Surly73

For a couple of years now I have been running M5 front, H&R 20mm rear, but I don't like how the M5 bar ends have a different angle that stresses out the front end links.

If you're worried about that, couldn't you swap out the original end links for the M5 end links? Or do they not fit?

[Surly73]

Originally Posted by Unspec

If you're worried about that, couldn't you swap out the original end links for the M5 end links? Or do they not fit?

Don't fit as far as I know - wrong length I believe. They aren't really expensive parts, or really difficult to change. If it was avoidable, I'd like to avoid it. Sometimes I think in certain situations (simultaneously braking, turning, and encountering an incline - like turning around in a driveway and 3-point turns) something gives a light crunch/rub.

[Surly73]

Originally Posted by BrowBMW

I used to daily drive an e30 m3 with a full roll cage, race seats, 5 point harness, dumped on motons, and I loved it. I think I'm willing to risk it :-)

Then go get the H&R 30/20 kit. Just be aware they're so big that they go beyond managing roll.

Also be aware that it will be rock hard side-to-side, but still nose dive, porpoise and squat like the barge that it is.

I wonder if you wouldn't be looking more for a KWv1 effect.

[BimmerHausPerformance]

Originally Posted by Surly73

Then go get the H&R 30/20 kit. Just be aware they're so big that they go beyond managing roll.

Also be aware that it will be rock hard side-to-side, but still nose dive, porpoise and squat like the barge that it is.

I wonder if you wouldn't be looking more for a KWv1 effect.

Kwv1 was what I was looking at doing in conjuncer with the sways. What do you mean by that? Thanks!

[ChiNorm]

I run OEM bars with KW V3 and there is no body roll any more at all. No wallow either, the thing corners like a skate board.

Good luck.

[Surly73]

Originally Posted by BrowBMW

Kwv1 was what I was looking at doing in conjuncer with the sways. What do you mean by that? Thanks!

OK - well if you're doing KWs anyways, try them first without the bars like ChiNorm suggests. There's a whole lotta slop that the KWs can take out. Personally, when I put my KWv3s on in a couple of months, I have no idea what bars I'm going to end up with. Might go back to stock at the start to see what's even necessary.

Doing bars can be done in the driveway on ramps, front and rear, so it's not like there's much "while you're in there" savings by doing it all at once.