[MacklinUSOB]

Originally Posted by Marlinman

I would also imagine then B14s would be overkill if not tracking....hmm thanks for posting I will be considering this set up.

Just remember, satisfaction with suspension feel is just about as subjective as you can get. Overkill for one is more than likely desirable for some others. Coming from the 704 M Sport suspension, I feel it needs a huge kick in the ass to behave to my liking, hence B14's. Also, this is the first I hear of B6's causing top hat rattle.

[MacklinUSOB]

Originally Posted by pjkbrit

This matters....the top hats take ALL the bump thump and they are considered a wear item...I got Febi brand off of E Europarts....not expensive and very obviously better made than OEM.
Did all work myself.

This is helpful, thanks. Did you find these listed on eEuroparts.com or did you need to place a special order? I can't seem to find Febi#102532 anywhere in their catalog. Out of curiosity, how much are they? I'm thinking I should have mine replaced since they have 63k on em.

[pjkbrit]

Originally Posted by Marlinman

is your car x drive? that may limit me.

Yes...x drive. Front shocks are x drive only application.

[akgambino]

Koni yellow. Not sure why nobody seems to give any love to koni yellow shocks/struts on here and only think the b6 or b8 are the only option. The knock on bilstein shocks has always been harshness/too stiff/not comfortable. Koni has similar to stock compression with adjustable rebound. It's the rebound that makes the stock drive suspension feel floaty/bouncy/wallowy/crappy, get faster rebound from your suspension and it feels way better and more comfortable while handling better.

[harperium]

Originally Posted by akgambino

get faster rebound from your suspension and it feels way better and more comfortable while handling better.

I thought that dialing up the rebound stiffness on Koni Sport yellow made the rebound slower? The YouTube videos show the damper as rebounding slower when stiffer, and rebounding faster when softer.

[benqo]

Originally Posted by pjkbrit

Lowered 3/4" all around...M Sport springs came off a low mileage 335 RWD car...they fit just fine and the B4s are perfectly matched to these Springs. The B4s are about 10% stiffer than the OEM garbage factory X-Drive cars come with. I FINALLY have the perfect balance of ride, handling and roll. I DID change the front top hats with the new struts....the OEM ones were shot at 50000 miles only. This matters....the top hats take ALL the bump thump and they are considered a wear item...I got Febi brand off of E Europarts....not expensive and very obviously better made than OEM.
Did all work myself.

The WORST thing with the stock F30 IMO is the base suspension...far too soft, too much bound, too much roll...at high speed the handling gets sloppy. As I said before B6s are overkill....unless you are tracking the car in which case I suspect they would rock...but on the road the B4s are just right...and I am VERY picky.

Sorry to bring this old thread to life. I am considering this setup and just wanted to ask pjkbrit if you have a long-term update on the B4 + M Sport combo? Any issues with the B4s (considering they are made for standard springs)?