Unstable over patches and bumps

[hatepotholez]

Hi everyone, just purchased a '08 128i with sp. The handling is unstable over patches and bumps, over wet roads it is even more unstable. I sometimes have to hold the wheel with 2 hands on occasions to keep it straight. I'm going to change out the tire obviously, but haven't yet decided to replace that tire, the front set or just go to non-rft all around.

BMW is saying there is no issue with the suspension, but I hardly doubt they actually gave a thorough inspection of the suspension and took it for a test drive.

Anyone experience this and had it repaired? Wondering if that bubble separated a belt or something.

Thanks,

Mo

[andrey_gta]

i upgraded my front sway bar and i gained stability. Roads that used to pull @ my steering stopped doing it.

Do you have the sport package suspension?

You should also look into replacing runflat tires for better rubber

[hatepotholez]

Originally Posted by andrey_gta

i upgraded my front sway bar and i gained stability. Roads that used to pull @ my steering stopped doing it.

Do you have the sport package suspension?

You should also look into replacing runflat tires for better rubber

I do have the sport package, did you only swap the front sway and not the rear?

Yea, highly considering changing out all the tires.

[andrey_gta]

yes just the front to e92 or e93 m3 swaybar. And noticed the change on run flat tires
I also have sport package.

Currently on winter tires and thinking about addressing the rear end bounce, esp for the summer since i will be getting non runflats. So read up on non runflats and what they mean for the car

[hatepotholez]

Originally Posted by andrey_gta

yes just the front to e92 or e93 m3 swaybar. And noticed the change on run flat tires
I also have sport package.

Currently on winter tires and thinking about addressing the rear end bounce, esp for the summer since i will be getting non runflats. So read up on non runflats and what they mean for the car

Will do thanks!

[RimasRS]

replaced runflats will do the job you will be surprised.

2 more things to change suspension springs from progressive to linear and M3 subframe bushings

[Evice]

during full heave motion, swaybars do not work, and I think what OP is describing is that. I've heard many times that the unstable feel is related to rear subframe bushings.

[Evice]

Additionally; From TC Kline himself.

"Bushings also play a major role in suspension dynamics, and Kline says that the 1 Series’ rear subframe bushings—parts it shares with the mass-market 3 Series—are its biggest shortcoming. Kline says they’re too soft and have too much vertical movement for enthusiastic driving."

2nd page on http://www.bimmer-mag.com/issues/101...1#.USX4XKUqaPs

[MLSavage]

Originally Posted by Evice

Additionally; From TC Kline himself.

"Bushings also play a major role in suspension dynamics, and Kline says that the 1 Series’ rear subframe bushings—parts it shares with the mass-market 3 Series—are its biggest shortcoming. Kline says they’re too soft and have too much vertical movement for enthusiastic driving."

2nd page on http://www.bimmer-mag.com/issues/101...1#.USX4XKUqaPs

Thank you so much Evice! This link is priceless!
135 has plenty of stock power, the first upgrades I was going to install were suspension upgrades. Now I know exactly what to aim for with my setup!

[hatepotholez]

Thanks Guys, I read Kline's article and it's very informative. Unsure if I will change over to M3 parts as of yet, maybe in the future.

Luckily the Pirelli Euforia had a free replacement and the car drives much much better. Didn't know a bubble in the sidewall can make such a big difference in handling.

[Perazzi]

I just had my rear subframe bushings upgraded to the M3 bushing and it was like I replaced worn out shocks. The bounce in curves has been replaced by a firm controlled ride. This is a must do upgrade.

And I have to thank the guys at Harrison Motorsports. If you are in the Atlanta area these are the guys to go to. They work only on BMW's, track their cars and have reasonable rates.

[HP Autosport]

Originally Posted by hatepotholez

Hi everyone, just purchased a '08 128i with sp. The handling is unstable over patches and bumps, over wet roads it is even more unstable. I sometimes have to hold the wheel with 2 hands on occasions to keep it straight. I'm going to change out the tire obviously, but haven't yet decided to replace that tire, the front set or just go to non-rft all around.

BMW is saying there is no issue with the suspension, but I hardly doubt they actually gave a thorough inspection of the suspension and took it for a test drive.

Anyone experience this and had it repaired? Wondering if that bubble separated a belt or something.

Thanks,

Mo

Any abnormal wear on your tires? How is your alignment? Worn our front thrust arm bushings(these last about 50K miles, sometimes less or more depends on road conditions)? Check your rear subframe bushings, guide rod and toe arms as well.

[Dackelone]

As long as your tires are not wor out or very low on thread.... I would suspect the rear suspension bushings. You will not believe how .u h nicer the M3 rear axle ushi gs .ake our cars drive. They lt only firm up the fear end wiggle ut the frknt of the car seems to track much better.

[SGM <3]

Originally Posted by andrey_gta

yes just the front to e92 or e93 m3 swaybar. And noticed the change on run flat tires
I also have sport package.

Currently on winter tires and thinking about addressing the rear end bounce, esp for the summer since i will be getting non runflats. So read up on non runflats and what they mean for the car

If you change the swaybars do you need to change the bushings and some other parts too? I think my stock ones are a little worn, so I figured I'd replace them with something better. Sorry didn't want to make a new thread.

[hatepotholez]

Originally Posted by HP Autowerks

Any abnormal wear on your tires? How is your alignment? Worn our front thrust arm bushings(these last about 50K miles, sometimes less or more depends on road conditions)? Check your rear subframe bushings, guide rod and toe arms as well.

I can only assume they are fine, based on the dealers findings. Would bushings be covered under CPO?

[HP Autosport]

Originally Posted by hatepotholez

I can only assume they are fine, based on the dealers findings. Would bushings be covered under CPO?

That you will have to check with your dealer.

[andrey_gta]

Originally Posted by SGM <3

If you change the swaybars do you need to change the bushings and some other parts too? I think my stock ones are a little worn, so I figured I'd replace them with something better. Sorry didn't want to make a new thread.

Yes, e9x m3 sways need their own busings & bushing holders/mounts

[fe1rx]

Originally Posted by hatepotholez

I can only assume they are fine, based on the dealers findings. Would bushings be covered under CPO?

Why was this thread not just left to die?

The OP hints at a 'bubble" that he later clarifies was in the sidewall of his tire and when fixed, fixed the problem.

How can he now reply "I can only assume they are fine" to the question "any abnormal wear on your tires?"

He doesn't need swaybars or bushings or anything like that.

How about we go back to square one and say, when something obvious is wrong, fix it before you start looking for other explanations for your symptoms. And maybe we should add, when you are starting a thread, include the relevant details.

[hatepotholez]

Originally Posted by fe1rx

Why was this thread not just left to die?

The OP hints at a 'bubble" that he later clarifies was in the sidewall of his tire and when fixed, fixed the problem.

How can he now reply "I can only assume they are fine" to the question "any abnormal wear on your tires?"

He doesn't need swaybars or bushings or anything like that.

How about we go back to square one and say, when something obvious is wrong, fix it before you start looking for other explanations for your symptoms. And maybe we should add, when you are starting a thread, include the relevant details.

I had bubbles on many tires before, and it never caused this kind of issue. Granted these would be my first run flat, so pardon the noob question. Next I verified all tires are good, BMW says the suspension is ok, nothing is out of whack. There is still some sort of "lingering" or float. All tire pressures are ok, btw.

[IGoFast1589]

Personally, I think the 2 biggest flaws of the many flaws in the 135i's suspension are the pathetic bushings and the dampers. The bushings feel like they're equivalent in terms of deflection to gummy bears and that includes the control arms, all the suspension links, subframe bushings, transmission mounts and all that shit. Beyond that, the dampers suck. They have no bump travel and don't react fast enough to road imperfections. Combine that with the crappy stock run flat tires and it makes for a ride that's not only jarring over minor imperfections, but also soft and difficult to predict. Get a proper set of dampers with good rebound valving with proper bump stops and you'll be happy. Bilstein dampers have internal bump stops and Koni's are external. With the Koni's you could go BMW Performance bump stops, Z8 or E36 M3. They're all substantially shorter than the factory bump stops which minimize the stroke. Plus the factory dampers are twin tubes and a good monotube damper will always have faster reaction to road bumps and dissipate heat more efficiently.

[John_01]

The rear suspension of the one series has some kind of designed-in dynamic toe control. It makes the rear wheels toe-in as the suspension is compressed. It also makes the car steer in the opposite direction of the body roll. When driving quickly on bumpy country roads its a noticible effect and needs steering corrections sometimes. I still have the stock rear bushings on the rear subframe which may contribute to this issues, although I have no way to know.

[Zombie1]

Originally Posted by Perazzi

I just had my rear subframe bushings upgraded to the M3 bushing and it was like I replaced worn out shocks. The bounce in curves has been replaced by a firm controlled ride. This is a must do upgrade.

And I have to thank the guys at Harrison Motorsports. If you are in the Atlanta area these are the guys to go to. They work only on BMW's, track their cars and have reasonable rates.

Been looking for an answer about this for awhile thanks