[Dynamics99]

Hi,

I recently installed MTS Technik Street suspension on my '11 335i which rides like a cloud but on some sharp bumps I feel like I'm bottoming out and worry I can damage my front control arms or subframe. The streets in Philadelphia aren't the best. I have 2 finger gap between the tire and the fender on the front and back and I'm on style 230 19-inch wheels. I replaced the sway bar end link with Meyle HD which has reduced some clunking sound as the original sway bar end link was too worn. Am I paranoid or am I experiencing a pothole explosion? I am scared to death when it happens. I feel like my front tires will blow. Usually over dips and small bumps, it rides normally.

Also, my sway bar bushings are bounded to the sway bar. Do I have to get a whole new sway bar to replace them? I couldn't pry it off with my fingers or a small pry bar.

[Dynamics99]

Update:

Okay, I think it's the bump stops that are making that huge noise otherwise my front tires would have popped by now considering they don't rub or the subframe does not scrape as I'm not even lowered. What front shorter bump stops could I get?

[mattanderson]

Did your suspension setup come with bumpstops matched to the kit?

I'd be skeptical that swapping around to random bumpstops would be any better than what came with the kit.

[dmatre]

If you are crashing on the bump stops, then you don’t have enough spring rate/shock damping for the weight/travel of your car.

Getting shorter bump stops will only result in even harsher crashes (same force, shorter distance for bump stop to act).

Lowering the suspension requires increasing the spring rate/compression damping in order to avoid bottoming out the shock/strut.

[Dynamics99]

Originally Posted by mattanderson

Did your suspension setup come with bumpstops matched to the kit?

I'd be skeptical that swapping around to random bumpstops would be any better than what came with the kit.

It did come with its own bump stop. The spring system is progressive and not linear.

[whyzee125]

It sounds like the springs are just too soft. The best riding setup I had was Tein S tech springs with Koni shocks (and e30 front hardware for an additional 19mm travel). It sounded just like you describe, fantastic ride quality, possibly better than stock on most terrain but big dips and imperfections would cause the front to slam into the bump stops and create the explosion noise in the strut towers. I haven't heard of that setup but I would look into something else that's tried and true if you can't live with it as is.

[crashoverride]

I don't see any mention of the condition of your shocks. Are they new enough not leaking etc..??

[gunnerxq]

The bump stops could be too long. I have Koni actives with eibach springs. They need all the travel they can get. I put on after market polyurethane bump stops. They were still too long so I cut them and the only part left is from the blue line up. The white one's are sport suspension bump stops.

Car drives like a dream.

[colinrichardson]

Originally Posted by gunnerxq

The bump stops could be too long. I have Koni actives with eibach springs. They need all the travel they can get. I put on after market polyurethane bump stops. They were still too long so I cut them and the only part left is from the blue line up. The white one's are sport suspension bump stops.

Car drives like a dream.

Are those speedthane hard?

I have a similar setup (koni active and HR springs) and am hoping this is solves the pothole explosion issue for me.

[gunnerxq]

Originally Posted by colinrichardson

Are those speedthane hard?

I have a similar setup (koni active and HR springs) and am hoping this is solves the pothole explosion issue for me.

Yeah they're on the stiffer side. You can go with the white or red if you want to try softer. I would still shorten the bump stops. You need as much travel as you can get

https://www.resuspension.com/catalog...RE-BR-COT58-40

[gunnerxq]

Originally Posted by colinrichardson

Are those speedthane hard?

I have a similar setup (koni active and HR springs) and am hoping this is solves the pothole explosion issue for me.

After you cut them you might still have to trim the inside for it to fit over the shaft.

[rvphuerta]

I had had MTS on my E46. It was great for daily driving. How low are you and did you install that extra black bump stop. I did not install the extra black bump stop. How much bump travel do you have at static ride height. The bump stops are on the hard side. I had about 1.64 inch of bump travel at static height before the bump stops engage. I believe your front spring rate is 342 lbs. You said you had the street coilovers not the comfort? The comfort have a 268 lbs spring. I looked at you springs length and its 5.5 inch if it's the 342 lbs, I think a bit to short for the rate. Could be coil binding. Look more into the specs. That spring has 3.70 inch of travel given the average weight E90/E92 with 170 lbs drive the spring deflection is 2.51 inch leaving 1.19 inch of spring travel. The E46 won't have that issue since it uses a 6.69 inch spring.

What is your height?
How much bump travel do you have?
Did you install the extra black bump stop?