[dermalres]

I had a G20 M sport previously that handled really well, especially when taking corners, roundabouts, sharp turns, etc. Steering on the G20 was perfect too (no under/oversteer) - I loved it!

I recently upgraded to a 520D SE (F10) and its handling and suspension is horrible compared to my G20 baseline. I appreciate that I cannot have the G20 suspension & handling characteristics but I need some ideas on what I could do to make it handle much better, especially when taking corners, turns, roundabouts, etc. as the back end definitely feels like its rolling/floating or something like that so I have to compensate by reducing the throttle and steering into the direction. Also probably doesn’t help that I have Bridgestone tyres on the F10 (G20 had Pirelli’s). F10 currently has 245/45R18 96Y tyres on 18’’ alloys.

Ideally I’m thinking I could do the following but need some advice/guidance as I’m not entirely sure myself what could be done. Welcome any ideas/suggestions/brands that could improve the handling and suspension of this vehicle so its as close as possible to the G20 M sport.

I’m thinking I could replace the following in the F10 (without sacrificing all the comfort):

1. Coils (front and rear)
2. Anti roll bar (front and rear)
3. Dampers (not sure this is necessary??)

What do you guys think?

[sszablya]

I managed to get some new old stock Eibach sway bars from a fellow forum member. They were super easy to install on my 550i Xdrive. They do an outstanding job of reducing the body roll, especially when pushed hard. I’m a big fan. I think they’re out of production now, though, so they may be difficult to acquire. But if you can find something like that, it was a great upgrade for me.

Everything else is factory- springs, shocks, struts, control arms, etc. with 120k miles on them.

I did notice after the installation I would get a popping noise when the suspension deflects a large amount on one wheel at a time (like when crossing a drainage path in a parking lot from a non-perpendicular angle). I think this is perhaps bad sway bar end links and I have some replacements ready to be installed in the spring.

[dermalres]

Thanks for this
Any idea where I could find something like this? Or could I maybe fit the m5 version on to this ?

[paul223]

Best Cheapest option is Bilstein B12 pro kit. Upgrade to 535i msport sway bars. Any thicker sway bar feel’s bouncy and tips too much side to side, essentially takes away independent suspension feel.

[Surly73]

The Eibach and H&R sway bar kits include 30mm front and 20mm rear bars.

While I still had stock suspension I found the 30mm up front was too much, and the stock bar was unbearable in terms of lean. The DRIVER PERCEPTION of lean is most influenced by the front bar. I also have the M5 front and 650i rear bar in my inventory. The stiffer rear bar is needed more to correct the balance of the car (stiffening the front without stiffening the rear dramatically increases understeer) but the stiffer rear bar does not do much to control the FEELING (i.e. driver perception) of leaning in corners.

While on stock suspension I settled on M5 front and 20mm rear bar.
Now on KWv3s I have gone back to stock front bar and 20mm rear bar after driving for 1+ years on M5 front/20mm rear.

The M5 front bar causes the end links to bend at strange angles and, in some circumstances, things in the X-Drive suspension can make contact which normally do not. It was a bit of a relief to get back to the stock front bar and new end links. Roll increased some, but turn in and cornering balance improved so it was worth it.

IMO from a handling balance perspective (over/under steer) it could still use an even larger rear bar, but I don't believe such a thing exists.

For what it's worth, on my E39 528i w/option 704 suspension, I swapped the stock rear bar for the M5 factory bar and it transformed the balance - nearly neutral.

To the OP: What was the G20 "M Sport". These days "M Sport" usually means all kinds of cosmetic stuff and you need to dig deeper to find what actually drives performance. Was it a true option 704, non-electronic, passive suspension package, or was it DHP + ARS + more active suspension toys that made it seem so good? F10s come the all-electronic way too, which some people love.

[Double Nickel]

Love the Eibach sways, night and day difference couple that with H&R vtf coilover and ebay strut bar feels really good.