[vinnyzbmw]

I've recently purchased my first BMW, 2016 428i Gran Coupe M Sport! I love the car however as the story goes there were things I didn't know to look for and now am researching options; the second of which is the suspension.

My BMW has M Sport Suspension that is not adaptive. Most of my driving is to work and back and with my family around town. I like to take the occasional corner however those times are fewer than the desire for a comfortable ride.

I'd be fine with replacing my current suspension setup with a permanent solution that provides a comfortable ride, Texas roads are harsh and bumpy...

What are my options, can I purchase factory shocks/struts for the standard BMW suspension and achieve a comfortable ride without sacrificing too much in the performance arena?

[cfm56d7b]

What size tires does your vehicle have? 18", 19"? Run flats or regular tires?

[vinnyzbmw]

They're 18" wheels with Bridgestone Potenza S001 tires and i'm not sure if they're run flats.

[Kraftwerk]

They're likely the run flats (RFT) if they're original BMW tires. Get rid of the run flats and thank me later.

[cfm56d7b]

Originally Posted by vinnyzbmw

They're 18" wheels with Bridgestone Potenza S001 tires and i'm not sure if they're run flats.

How many miles does your vehicle have on current Bridgestone Potenza S001 (most likely run flat) tires?

Among most popular run flat tires, Bridgestone Potenza S001 provide a harsher ride.

[kern417]

you could also probably swap out the stock struts for adjustable ones then turn the dampening down

https://www.ecstuning.com/b-koni-par...t/8741-1582kt/

[Jvac]

Seriously, try getting rid of the run flats first. You have the same tires I had on my 335. I switched a couple of weeks ago and it made a huge difference. Softer ride and quieter at speed. The s001 rft is carved out of granite it seems. Not to mention they are about 400$ EACH and a decent set of 4 replacement tires can be had for ~600.

Report back after this and we'll see about suspension changes if you still aren't happy. I'm in Dallas BTW. I agree the roads are pretty bad here
Totally unrelated note, I have a spare s001 rft available for purchase. Size 225/40/19 with 8/32" tread depth. PM an offer if you like. I've been too lazy to put on the classifieds page yet.

[vinnyzbmw]

Originally Posted by Jvac

Seriously, try getting rid of the run flats first. You have the same tires I had on my 335. I switched a couple of weeks ago and it made a huge difference. Softer ride and quieter at speed. The s001 rft is carved out of granite it seems. Not to mention they are about 400$ EACH and a decent set of 4 replacement tires can be had for ~600.

Report back after this and we'll see about suspension changes if you still aren't happy. I'm in Dallas BTW. I agree the roads are pretty bad here

Awesome, thanks for the feedback! Out of curiosity, what tires did you switch to?

How many miles does your vehicle have on current Bridgestone Potenza S001 (most likely run flat) tires?

25,000 miles

[Jvac]

I got the Firestone indy 500s. I Don't really need all season tires for just a few cold days a year and good ones are expensive anyway, so I stayed with the summer rubber (the s001 is also a summer tire). Mine are 19s so a set of 4 was about 560 and then tire rack has 60$ rebate running right now. Considering the Michelin ps 4s are 1.5x the price and supposedly wear out faster, I couldn't justify the extra cost. The Firestone are plenty adequate - rated up to 168mph. I had them on my last car too and had no complaints. Lots of other guys from here running them as well, with all positive comments.

[Larry77]

I just switched to Continental DWS06's and they have been amazing compared to the Pirelli RF's from stock. If that doesn't work I'm sure you could find someone to swap you the non-sport suspension for your m-sport and they would probably do the work for you...
Larry

[vinnyzbmw]

I just scheduled an appointment for noon today at firestone to install the Indy 500s! I'll report back with my thoughts, I really hope this helps!

[wdeerfield]

i went from 18" contisportcontact RFT to 19" MPS4S and even upsizing to a 19 the ride is so much better on go flats. Switching to the Indy 500s should definitely help

[vinnyzbmw]

So i installed a set of Firestone Indy 500s as stated above and decided to have a little fun with this. I downloaded a seismometer application to do before and after analysis of the ride quality as it relates to comfort. You'll notice that on the suburb street there's a neglegable difference in peak magnitude however on the highway it's more obvious, the non run flat tires have smaller peaks.

Suburb Street - 45 MPH


Highway - 75 MPH


Legend
Orange: Firestone Indy 500
Blue: Bridgestone Pirelli S001 RTF

Sizes
Front: 225/45/18
Rear: 255/40/18

2016 428i Gran Coupe with M-Sport package

Note: Both sets of tires were properly inflated to the recommended tire pressure of 32 PSI front 35 psi rear.

My takeaway, I agree with the data. On the suburb road the Firestone (non run flat) tires definitely filter out some of the minor imperfections however the more pronounced are still there in equal magnitude. On the highway it was smoother overall. Given that the majority of my commute it on the suburb like streets depicted above i'm going to look into suspension alternatives. For the record, Texas roads, or at least the roads in DFW are really pretty rough.

[Jvac]

I have been reading a lot of the suspension threads for research. Eventually I would like to track the car and so I'm reading up with that goal in mind. I just can't see replacing the factory Struts until they are worn or I win the power ball. It seems like most of the discussions here are centered on lowering the car (to eliminate body roll or just for looks), and /or stiffening the chassis (aftermarket shocks, sway bars, control kits etc) for better sport performance driving. And a lot of the guys are on x-drive cars which apparently ride higher and wallow more. In general these changes would result in a firmer ride, not a more comfortable one, although some of the expensive coil over kits seem to get high marks all around. Roads and traffic are 2 of my biggest disappointments since since moving to DFW. A pretty modern, clean city but the roads stink! I feel your pain. No wonder everyone is driving trucks
By the way I'm told new tires have a breaking period of about 500 miles. One should wait to form an opinion until they have worn in a bit... Interesting stuff with the seismic app though.

[exE36M3]

FWIW, the set-up I have always enjoyed most are the Eibach pro-kit (for about a 1" drop) and Koni's adjustable shocks. It's a great street ride - not harsh at all, and can flatten a corner nicely.

With the Koni's (Yellow, Single-Adjustable), you can adjust them for track days or spirited driving. MY last set lasted over well over 100k on my E36 M3.

[vinnyzbmw]

As a follow up to my post, there may be some truth to the break-in period of tires, it feels much smoother now . I'm going to do another test on the same strip of road with the seismograph and post back.

[ouengineer]

Getting rid of the stock run flats for some good performance tires completely transforms the car. Way better ride, less noise, better steering feel, more grip. All that is needed is a compressor and patch kit for the trunk.

[bimmerbot]

I recently got a 340i m sport, previous owner seems to have changed to springs or something because it seems lower than usual.

Any idea how i can get the stock spring or a very good alternative ?