550isport

I read somewhere that the Active Roll Stabilization allows for the softening of the shocks and springs, since they are no longer need to control body roll. It sounds great, flat cornering, and a more supple ride. And I think it works well, but something happened recently that made me wonder:

My last car and 1st BMW was an 01' 740i sport which, unlike the 740il sport and any E65 7 series, had a suspension tested and tuned by M division - properly known as an M technik suspension (the same ilk which I believe an E60 M sport has - not avail. in U.S.). It was stiff, but it really transformed the personality and handling of the car. So, years ago I had a friend with me in my 7 who was a mercedes guy that loved his CLK 430. On a highway near his house he warned me incessantly and profusely to slow down (from 145) because there was a pronounced dip in the road. I was familiar with the dip. I did not slow down and the car simply swallowed the dip without any drama at all (like a Toyota would have at 55) and continued on. My friend was amazed and told me his Mercedes almost bottomed out at 120 over the same dip. I was not surprised.

Fast forward four years. I took my brand new 550i sport over that same dip at 120 and felt the car 1) move a bit horozontally and 2) compress its suspension more than I expected - although not bottoming out.

Does anyone else feel the 550i sport could use a slightly stiffer set up? BMW has long been applauded for its sports packages, which unlike Merc, Audi and some Japanses cars go beyond mere looks. I feel that the ride in a 550i sport is supple enough to pass for a standard suspension (I know two older yentas who love their 550i sports). I think BMW should offer the Roll Stabilization on a standard 550 w/out sport pack as well, and then make the sport suspension...well, a bit sportier. Anyone agree, disagree. I'm going to look into Dinan suspension, but my car is a lease, and I don't like the 'lowered' look.

Regards,
DRP

CVTBenhogan

Its my first BMW so I've got no comparsions.

I do have a couple of quick thoughts.


1) Yes, the 550 sport suspension is likely softer than before. Active roll is designed to kick in for hard cornering forces, thus, compensating the softer suspension bits that are in place for ride comfort and typical driving conditions. I guess its a best of both worlds concept.

2) Most cars with sport packages are really rough and generally suck. The A6 sport is said to have wheels made of concrete/brittle, which I agreed with instantly while test driving it.

3) I find 550 very comfortable, even with RFTs. If one commuted 200 miles a day, I'd sing a different tune.

4) Some people are forgetting that BMW is moving towards more luxury than sport, as Lexus moves the other way. Tired of interior versus driving arguments?

5) Maybe BMW handling needs more focus as competitors are copying the formula. I can't help but think the M5 should handle better, as its not the dominate big boy it once was. Cars are getting too heavy due to the equipment options.

CVT Benhogan

RHMax

I agree that the car feels a bit floaty on certain bumps; could be angle and/or speed. But sometimes it's still a little too stiff for my wife and our little passenger.

my530i

Sometimes, it depends on your car tire pressure. I currently have 34psi (f) and 38psi?. When running over the bump or rough road, I feel like the car is jumping on the road. Not as stable as expected. I think tire pressure has an important role in handling department.

jet190rs

my 545 sport is waaaaay too soft, especially compared to older bmws.

ars is a neat idea. it stays pretty flat for most everyday turns, but when you start to really push it, the car does roll a lot, and i'm not even talking about cornering "at the limit".

there's also too much vertical bounce/bopping. for example, when you brake hard, the car's front end dips way too much for a so-called "sport sedan". this is the same as when you described your car's suspension compressing too much at the dip.

i think bmw is getting too soft in general. every generation they get softer.
compare e60 vs e39 or e90/e46 vs e36/e30...

m cars are still fun to drive but they're so heavy these days that they're betted suited as a gt car, not a sports car.
compare e30 m3 vs e36 m3 vs e46 m3...

bmws are still sportier than the competition, but not sporty enough compared to older bmws. sadly, this may be my last bmw...

Ray Hull

What tires have you on these cars? Last year, it was reported that BMW would begin tuning their future suspensions to ThumpFlat tires. Don't know if that has come to pass after the early and undoubtedly costly disasters with ThumpFlats, but it certainly warrants a large measure of consideration before issuing any "soft" rating.
Cheers,
Ray Hull

ImolaRedM

I agree... I used to think my E39 540i sport was a little soft but it was mainly due to the body roll. Suspension was good in that car. Now I think the E60 body roll is fixed but the suspension is a bit soft. It seems that BMW tried to make up for the stiff sidewalls on the sport tires. Another possible reason for the softer springs is for better launches. It wouldn't be the first time BMW did this either. In the US market, BMW put softer springs in the rear of the M Roadster (Z3) than in the normal Z3. Issues with cornering were addressed with thicker anti-sway bars and better shoes but they felt Americans wanted faster 0-60 times and made the car softer sprung in the rear.

550isport

I agree with you completely. The more I drive my car the more I realize that what I love most about BMWs is the firm ride and no-nonsense handling. Power is to fun like money is to love. Good luck being in love if you are totally broke, but money alone won't buy love. Power becomes boring after a while. That is why the AMG cars don't appeal to me as much. Handling is what keeps you smiling and makes you take the long way home. So I am going to look into the real cost of a Dinan suspension. I am also going to inquire about putting the shocks and springs from a european E60 M sport car (essentially the M5 suspension - but the layout is a bit different in an M5 and so I don't believe the shocks/springs swap out to another E60 as they should on an M sport suspension). I could buy these items in Canada and have them installed here.

DRP

windnsea00

Nothing a firmer spring/shock combo can't take care of (and I'm not talking about the lame H&R springs). Once you get use to aftermarket setup than stock will always feel soft and US versions are tuned softer/ride higher then the ones being sold right in Germany due to our worse roads. BMW uses great suspension designs which is why they can have very successful racing cars out of platforms based from there street vehicles.

I bet it wouldn't be too expensive to buy the spring/shock combo for the M-technic suspensions in Europe and little other odds and ends necessary for it to work well.

heezy545i

If you're going to go through the trouble of upgrading, might as well go aftermarket unless the m-sport suspension is available at an attractive price.

The dinan suspension would be good as everything is matched, but for the price of a stage 1 kit, you could get yourself a full coilover system from the likes of KW, ground control or bilstein.

If the dinan stage 1 interests you, you could buy the parts separately outside of dinan and save some money. For the most part, they just used rebranded springs and shocks. Not sure what springs they use for the e60, but the koni adjs should match well with many aftermarket springs.


The 550 might not be the best handling car, but it is a sedan that handles well for its size. I wouldn't mind if it were a bit more sportier, but overall I think the e60 offers a good compromise between sport and comfort. Sure you can have a better handling car, but you will lose a little comfort in the process. I like to push the car when the opportunity arises, but the opportunity really doesn't come that often. Again, the e60 may not handle like a sports car, but if you don't reach those limits, then what's the point.