Recommendation For suspention

[Ditcher]

Have a 09 135i with bad m sport strut. I'm pretty sure if that one is bad then the other is as well or soon to be. Debating on just buy a oem replacement or some coilovers. (b12 or B14) Is it worth the few extra hundred dollar to go coilovers?
Its my DD/fun car. I would like to at some point take it to a auto x. Probably wont be to often though. How ever I have mountains close by I can go carve out. Also like to note some of the roads around here kind of suck with pot holes and we all know how the 1er loves bumpy roads.
Is the performance of the coil over going to be noticeable over oem m sport?
Also don't want the car to feel like its going to fall apart hitting bumpy roads. lol
Recommendations are welcome. My budget is around 800.
Thanks for the help.

[asbrr]

For that budget, don't complicate your life. Go buy a set of B4 shocks all around, refresh all the strut mounts and small bits, and your car will feel 100x better.

[Blown95ImpalaSS]

Replace with b4 as suggested if you want to keep OEM ride comfort. If you want more performance, yes the coilovers will be much, much better. If you do coilovers, do the subframe bushings too, or at least the inserts, to help the coilovers do their job without the subframe deflecting

[ShocknAwe]

Are you doing the work yourself?

Ditch the runflats yet?

If yes to both, I recommend starting with Bilstein B6/8 shocks, swift specR springs, white line rear subframe bushings INSERTS(cheap and easy to start with) and Dinan camber plates for your OE top hat. If you can afford it I recommend the Monroe rear top mounts or the dinan part is even better too with strut/spring setups.

Then start working on the suspension arms once you have more money, you'll want the front lower arms and the rear guide rods. Once you do that, get solid aluminum RSFBs.

Stick with stock away bar. Rest of it can be done piecemeal. I think you'll like the setup

Feel free to PM with questions.

[MA128]

Hello to All,

I hope you don't mind if I jump in with a few questions as I am in a similar place as the OP.

My 2013 128 Msport 6MT has 99,000 miles and I am currently on my 2nd set of OEM BMW shocks, installed about 35K miles ago. M3 RSFB were installed 15,000 miles ago along with new OEM front control arm bushings - better but not perfect. I still have some rear bounce and (I think) lateral rear suspension motion that I want to cure. I'm retired and this is my DD. I'm looking for greater control and high speed (80MPH) straight line stability while maintaining DD ride comfort. Tires are Michelin Pilot Sport A/S3+.

My plan is to install Koni Special Active shocks all around including the Dinan rear upper strut mount. The question is - should I do anything else? I'm not interested in coilovers or dropping the car at all. I had a full M3 front suspension and Koni FSD shocks installed on my 2009 128 and it was magnificent on the highway. Problem was it was way too harsh up front on poor pavement and city streets so that is not under consideration this time.

Thanks in advance for your thoughts and suggestions,
Paul

Edit: The harshness referred to above was due to the M3 control arms, not the shocks (which I liked).

[blue135]

I think the Special Actives are the successors to the FSD. I have Special Actives on my 135i. I do not notice the issue with harshness you mentioned, but these are not in the Yellow Koni league with respect to handling, I suspect (because I have not had the Yellows on this car).
I like the Special Actives.

[asbrr]

Originally Posted by MA128

Hello to All,

I hope you don't mind if I jump in with a few questions as I am in a similar place as the OP.

My 2013 128 Msport 6MT has 99,000 miles and I am currently on my 2nd set of OEM BMW shocks, installed about 35K miles ago. M3 RSFB were installed 15,000 miles ago along with new OEM front control arm bushings - better but not perfect. I still have some rear bounce and (I think) lateral rear suspension motion that I want to cure. I'm retired and this is my DD. I'm looking for greater control and high speed (80MPH) straight line stability while maintaining DD ride comfort. Tires are Michelin Pilot Sport A/S3+.

My plan is to install Koni Special Active shocks all around including the Dinan rear upper strut mount. The question is - should I do anything else? I'm not interested in coilovers or dropping the car at all. I had a full M3 front suspension and Koni FSD shocks installed on my 2009 128 and it was magnificent on the highway. Problem was it was way too harsh up front on poor pavement and city streets so that is not under consideration this time.

Thanks in advance for your thoughts and suggestions,
Paul

I'm wondering if the rear bounce is just weak/worn OE shocks again. If you have M3 RSFB, that really should have sorted out the subframe. There is play in other various bushings but seeing as this is a DD, doing the M3 thing in the rear isn't going to help.

The Dinan rear upper mounts supposedly provide another 10mm of travel before bumpstop engagement, that's a good thing. Did you replace all the ancillary bits when you put in your second set of OE shocks in the rear? Thinking the lower shock mount etc...that may contribute to the looseness if it's old/perished for example.

[tracer bullet]

Originally Posted by ShocknAwe

Dinan camber plates for your OE top hat

Are these thicker? Meaning - will they end up raising the front of the car at all? I vaguely remember reading they lift it a cm, but that may have been a different product altogether.

[MA128]

Originally Posted by blue135

I think the Special Actives are the successors to the FSD. I have Special Actives on my 135i. I do not notice the issue with harshness you mentioned, but these are not in the Yellow Koni league with respect to handling, I suspect (because I have not had the Yellows on this car).
I like the Special Actives.

Sorry if I wasn't clear - the harshness I referred to was from the M3 front suspension, not the shocks. Yes, the Special Actives are the successor to FSD. Thanks for the feedback on the shocks.

Cheers,
Paul

[MA128]

Originally Posted by asbrr

Did you replace all the ancillary bits when you put in your second set of OE shocks in the rear? Thinking the lower shock mount etc...that may contribute to the looseness if it's old/perished for example.

The BMW specialist shop that installed the shocks also installed a new full mounting kit.

Thanks for your response,
Paul

[ShocknAwe]

Originally Posted by tracer bullet

Are these thicker? Meaning - will they end up raising the front of the car at all? I vaguely remember reading they lift it a cm, but that may have been a different product altogether.

Not quite a cm. Roughly 1/4" thick i believe.

They pair with the specR springs well since those have some rake and the area remove some.

[fast1eddy]

Originally Posted by MA128

Sorry if I wasn't clear - the harshness I referred to was from the M3 front suspension, not the shocks. Yes, the Special Actives are the successor to FSD. Thanks for the feedback on the shocks.

Cheers,
Paul

The harshness is from the M3 tension arms specifically. The control arms add camber but no added NVH. I took my M3 tension arms off and went back to stock. Harshness gone. M3 rear arms do help rid the rear end of some movement and add zero NVH.

[asbrr]

Originally Posted by fast1eddy

The harshness is from the M3 tension arms specifically. The control arms add camber but no added NVH. I took my M3 tension arms off and went back to stock. Harshness gone. M3 rear arms do help rid the rear end of some movement and add zero NVH.

This is it exactly. I had new M3 tension arms and control arms installed when my factory ones wore out, and the increase in impact harshness was noticeable on broken pavement.