[thakid22]

Do not use non sport mounts on a vehicle equipped with the sport suspension package.
The result will be too much vertical movement of the front end of the car.

I installed Koni FSD struts and loved the creamy ride quality. These units gave the car a smooth magic carpet ride on most all surfaces. However, I removed the shocks after a couple thousand miles because I couldn't stand the amount of front and rear bounce on anything but perfectly smooth roads. The car displayed the typical E90 soft subframe bounce at the rear on freeway bumps, dips, and depressions. In the city too, the rear had sharp bounces whenever both rear wheels hit a bump at the same.
The front end felt less than optimally damped as well. Odd considering everyone considered the FSDs to be fairly well tied down.

I installed Bilstein HD struts all around for more control.
These shocks do have a break in period. The initial drive after installation was super firm! Dive, squat, roll, and body motions were next to non existent. The ride quality was uber harsh though. Control was perfect, but the ride was bumpy, stiff and loud too. I did immediatelynotice that the more I drove the smoother the ride got. After about two weeks the ride was smooth and civil, but the damping had settled to a level that allowed the front end to have a bit of up/vertical motion the suspensioned worked. It felt sorta elastic. Eerily like the FSDs. The rear of the car was perfect. No bounce at all with the Dinan upper strut mounts for the rear I added during the bilstein install.
I was starting to suspect the front subframe bushings we're worn causing excess bounce in the front. But then I remembered. I used non sport strut mounts up front during my koni install. I replaced these mounts with lemforder OEM replacement front mounts... #problemsolved

The front is now firm, compliant, and befitting a BMW. The non sport mount introduced harshness as well as undamped motion. Replacing these mounts with the sport mounts corrected the issue.

Anyway, I just wanted to let everyone know because it has been said you can use either mount regardless of your suspension setup. In addition, let me advise against Monroe strut mounts of any kind. I suspect the quality, durability and durometer are not a suitable match for the stock suspensions.

Having said all of that, I wonder how the M3 front mounts feel, probably better than the sport mounts. I like to try various brands/settings as pertains to struts. When I do the front end again, I'll try those stiffer M3 mounts.

Perhaps this was a lesson in NOT using Monroe parts (wtf was I thinking). Lowered non sport vehicles should be experiencing the same front end vertical motions due to the reduced spring height and increased spring rate (just like sport suspension). If not, then I guess the problem was the cheapo mounts, rather than incorrect (sport vs non sport) mounts.

I got longed winded. Sorry. I hope someone finds this useful though.

[cdgatti]

You may have seen my posts on here about my bilstein hd install. I too have experienced the ride getting better with time. I am now about 3 months and 3-4K miles on the new shocks and they are very smooth no harshness at all. I love being able to hit any damn hole or imperfection i want and the car just takes it in stride.

I put on lemfoerder sport mounts too, the ones with the 098 in the part number. I still wonder though what happens as these things compress, as many on here have noticed the new strut mounts are alot taller than the old ones as the rubber material compresses. I am thinking the rubber section just recedes deeper into the metal housing but the overall thickess of the strut penetration doesn't change so nothing loosens, the car just settles down 1/2" or so over time.

[thakid22]

Originally Posted by cdgatti

You may have seen my posts on here about my bilstein hd install. I too have experienced the ride getting better with time. I am now about 3 months and 3-4K miles on the new shocks and they are very smooth no harshness at all. I love being able to hit any damn hole or imperfection i want and the car just takes it in stride.

I put on lemfoerder sport mounts too, the ones with the 098 in the part number. I still wonder though what happens as these things compress, as many on here have noticed the new strut mounts are alot taller than the old ones as the rubber material compresses. I am thinking the rubber section just recedes deeper into the metal housing but the overall thickess of the strut penetration doesn't change so nothing loosens, the car just settles down 1/2" or so over time.

Yes. Those are the ones I used too. I think the strut mounts compress after relatively little use. My original mounts 120k mounts were flat on the bottom. The new Monroe mounts started out a bit domed on the bottom. When I removed them a couple thousand miles later, they were flat just like the original mounts.

The weight of the car permanently flattens the bottom of the mounts rubber after a period of time. I think this happens rather quickly and is perfectly normal. It seems the only consequence, is slightly lower ride height once they flatten.

+1 on loving the Bilstein HD's continually improving ride quality.

[drummr8]

How does this affect xDrive vehicles? I have xDrive and I'm installing coilovers, wondering if I should get the stock (31306785962) strut mounts or the sport ones (31306775098).

[Soravia]

Originally Posted by drummr8

How does this affect xDrive vehicles? I have xDrive and I'm installing coilovers, wondering if I should get the stock (31306785962) strut mounts or the sport ones (31306775098).

You get the xDrive specific mounts, I think. All xDrive have their own strut and springs, and front control arm bits. Sport or not, they are all the same for xDrives.

[vilord]

Has anyone compared the xdrive, sport, and non-sport/non-xdrive mounts?

The insulating gasket is the same across all three, the dust washer and support washers are the same, which leads me to think that the bolt pattern and tube diameter is also the same.

I'm guessing that just leaves ride height and perhaps 'stiffness'?

[tlow98]

Originally Posted by vilord

Has anyone compared the xdrive, sport, and non-sport/non-xdrive mounts?

The insulating gasket is the same across all three, the dust washer and support washers are the same, which leads me to think that the bolt pattern and tube diameter is also the same.

I'm guessing that just leaves ride height and perhaps 'stiffness'?

Xdrive suspensions are all the same regardless of sport/non sport. if you own a 335 it's different than a 328i, but otherwise the 'sport' package for x-drives was everything except suspension, sadly.

[vilord]

From the factory that is true, but no reason not to change it!

I'll be putting the non-xdrive sport strut mounts on my car.

They should be a little stiffer. They'll also *raise* the front about 8mm. I'll play around with adding and removing stiffener plates and possibly adding a poor road package spacer to the rear if needed to level it out.

[Blueeyesredpanda]

Originally Posted by vilord

From the factory that is true, but no reason not to change it!

I'll be putting the non-xdrive sport strut mounts on my car.

They should be a little stiffer. They'll also *raise* the front about 8mm. I'll play around with adding and removing stiffener plates and possibly adding a poor road package spacer to the rear if needed to level it out.

Did you end up putting non-xdrive sport strut mounts on your xDrive?