suspension upgrade for 128 - opinions?

[raldenlee]

I have a non-sport 128 and would like to firm up the ride slightly for better cornering and with a lower stance without sacrificing too much ride comfort. I'm considering several options.

1) BMW performance springs with Koni FSD's
2) BMW performance springs with and Koni yellows
3) Linear rate Msport springs with FSD's


My questions are: If I go with one of the BMW performance spring options,
will the springs be too firm to achieve ride comfort?

And if i chose the Msport springs will they be too mild to achieve significant cornering/handling improvement?

I have spent a lot of time researching this forum, but haven't found any spring rates for stock vs Msport vs performance springs.

[Bimmer-Bob]

Originally Posted by raldenlee

I have a non-sport 128 and would like to firm up the ride slightly for better cornering and with a lower stance without sacrificing too much ride comfort. I'm considering several options.

1) BMW performance springs with Koni FSD's
2) BMW performance springs with and Koni yellows
3) Linear rate Msport springs with FSD's


My questions are: If I go with one of the BMW performance spring options,
will the springs be too firm to achieve ride comfort?

And if i chose the Msport springs will they be too mild to achieve significant cornering/handling improvement?

I have spent a lot of time researching this forum, but haven't found any spring rates for stock vs Msport vs performance springs.

It's all way too subjective for people to really answer your questions, other than to offer their own personal opinions, which may or may not be consistent with your views.

Not having any experience with the BMW Performance springs, but knowing that they are an OEM application intended for street use, I can't imagine them being too harsh for anyone seeking to upgrade from the M Sport springs. I mean, they're basically the next step, right? You'd have to be awfully particular if you found the M Sport springs to be "not enough" but the BMW Performance springs "too much."

EDIT: Just read that you were coming from a non-sport suspension. That might change things. Still, I would think that if you were concerned enough to be swapping springs, then you ought to run at least the Performance parts. But bear in mind, this advice is coming from someone running much firmer rates.

[ozimmer]

Hi raldenlee
I am in a similar situation and recently asked related questions - see link:
http://www.1addicts.com/forums/showthread.php?t=892330

I will be interested to hear what you decide, but in the meantime I am leaning towards M-sport springs + Koni yellows or FSD. Just to complicate things, several people suggested stiffening the rear subframe bushes and fitment of an anti-roll bar may be worth doing at the same time.

[raldenlee]

I already have the M3 front swaybar, and plan on adding rear subframe bushing inserts (powerflex or whiteline, if the latter ever come off back order). My problem comes from lack of objective data on the spring rates for the springs I'm considering. If anyone has that info, it would make my decision a lot easier.

[John_01]

There is some info about the spring rates in this thread:
http://www.1addicts.com/forums/showthread.php?t=290954

The stock M-sport suspension was too soft for me, as it reminded me of driving a Toyota. With upgraded dampers, M3 sub frame bushes and the M3 front sway bar, it should be a good improvement and still very comfortable. If you want it to feel like a sports car, the performance springs will be a better choice. You will notice some trade off in ride quality on bad roads.

[timhatimay]

Quite a few forum members have done BMWP springs with koni dampers. I think generally the yellows are considered a little bit more performance oriented and the FSD on the more comfort side. They should both be a great improvement over stock, and the guys that have them seem to love it.

Personally, I don't think there is too much difference with the m-sport suspension compared to non-sport. I've driven some 128i's and it didn't feel much different. So if you are going through the trouble I think you would be more bang for the buck with the BMWP springs. Any reason you aren't considering the full BMWP suspension? The shocks are matched to the springs, so it is a nice set up. I have this, and I really love the way the car handles. It is noticeably stiffer, however I think the end result was more comfortable than stuck in most cases. There was a thread on e90 where they had spring rates of different OEM and aftermarket springs. It may not be exact for the e82, but should give a good idea.

Tim

[raldenlee]

Thanks for the info guys. From what I've been able to find with your help, Msport spring rate should be about 120 lbs/in. BMW claims the PS is 34% stiffer than that and 48% stiffer than non-sport springs. Working backwards, that would make the non-sport springs about 109 lbs/in, if my math is right. And that's consistent with Tim's experience that there isn't much difference between Msport and non-sport springs. So perhaps I should go with the PS springs and either PS shocks or one of the Koni's. Harold at HPA recommended the Yellows over FSD's when using the PS springs and I also see that Koni doesn't recommend FSD's with lowering springs. I like the potential for adjustment on the Yellows but truth is I probably would just set them at full soft and leave them there. Makes me wonder how the PS shocks would compare. Anybody know?

[Dackelone]

OP or anyone thinking of a suspension upgrade should read this article...

The Ultimate Handling Machine
TC Kline’s suspension tuning transforms the entry-level 128i Coupe into a car that can rival the 1 Series M Coupe for pure driving fun.
http://www.bimmer-mag.com/issues/101...e#.UlBdCdKBnSw

[raldenlee]

yes I read that article and was interested in the spring rates quoted:

stock 128 = 125f/350r
TC Kline car = 350f/500r (street and track use)
TC Kline recommendation for DD = 350f/300-350r

So basically stock rear springs with much stiffer than stock fronts, a combo that would probably only be available in coilovers.

[HP Autosport]

Originally Posted by raldenlee

yes I read that article and was interested in the spring rates quoted:

stock 128 = 125f/350r
TC Kline car = 350f/500r (street and track use)
TC Kline recommendation for DD = 350f/300-350r

So basically stock rear springs with much stiffer than stock fronts, a combo that would probably only be available in coilovers.

And do remember that the article is all personal opinion. I highly respect TC's opinion but he just likes his cars to ride softer. You can add spring rate without over compensating the dampening. When you get down to the bottom line, it all depends on how the driver likes to drive and how he wants his own car set up.

-Mike