[RMNB]

Thinking about Koni FSD and Eibach spring kit. Does it even make sense to entertain the idea of sway bars on front and rear? Will the mild drop and and new shocks level it out around corners? What sway bars would work on a E92 cpe X-Drive? Prod. date is 1/2012 if that helps.

[AtlasM]

You can use any rear sway bar on the xi same as the rwd car, but UUC is the only company that makes a front sway bar for the xi. They're back ordered right now because they don't have any bushings in stock. I ordered a set before their site listed them as back ordered, didn't get any notification they were back ordered, and only learned this when I checked their order status page a few days later. Several calls to UUC resulted in no real answer on timeframe of when they would have the bushings made and no concrete reason for what was taking so long on the bushings being made. I canceled my order.

Instead, I'm doing Strongflex poly bushings and Ground Control adjustable end links on the stock front sway bar, and an E93 M3 rear sway bar with M3 bushings and Hotchkis end links. Both sets of end links are getting Seals-It rod end boots because they have exposed rod ends and I'm trying to keep them quiet. Well, the Hotchkis rear links have ball joints on one end of them, and the Seals-It boots come in a 6 pack which is the exact number of rod ends I'll have.

Replacing the rear sway bar requires dropping the subframe so if you do it, most folks also do subframe bushings at the same time. I went with Whiteline KDT917 bushings (not inserts).

These are all going on the car on Thursday along with Koni FSDs and B&G S2 springs, which drop the car a little bit lower than Eibach but otherwise mostly similar. I'm using E36 M3 front and Z4 M rear bump stops which are a bit shorter, to regain suspension travel and help the shocks do their job.

I chose the E93 M3 23.6 mm rear bar because with awd and staggered tires (I have 235/35-19 & 275/30-19 like you) I wanted more rear roll stiffness, but didn't want a radical increase in relation to the stock front sway bar. The aftermarket rear bars, even with smaller diameters than E93 M3, are solid vs. the hollow M3 bar, and thus much stiffer.

[RMNB]

Originally Posted by AtlasM

You can use any rear sway bar on the xi same as the rwd car, but UUC is the only company that makes a front sway bar for the xi. They're back ordered right now because they don't have any bushings in stock. I ordered a set before their site listed them as back ordered, didn't get any notification they were back ordered, and only learned this when I checked their order status page a few days later. Several calls to UUC resulted in no real answer on timeframe of when they would have the bushings made and no concrete reason for what was taking so long on the bushings being made. I canceled my order.

Instead, I'm doing Strongflex poly bushings and Ground Control adjustable end links on the stock front sway bar, and an E93 M3 rear sway bar with M3 bushings and Hotchkis end links. Both sets of end links are getting Seals-It rod end boots because they have exposed rod ends and I'm trying to keep them quiet. Well, the Hotchkis rear links have ball joints on one end of them, and the Seals-It boots come in a 6 pack which is the exact number of rod ends I'll have.

Replacing the rear sway bar requires dropping the subframe so if you do it, most folks also do subframe bushings at the same time. I went with Whiteline KDT917 bushings (not inserts).

These are all going on the car on Thursday along with Koni FSDs and B&G S2 springs, which drop the car a little bit lower than Eibach but otherwise mostly similar. I'm using E36 M3 front and Z4 M rear bump stops which are a bit shorter, to regain suspension travel and help the shocks do their job.

I chose the E93 M3 23.6 mm rear bar because with awd and staggered tires (I have 235/35-19 & 275/30-19 like you) I wanted more rear roll stiffness, but didn't want a radical increase in relation to the stock front sway bar. The aftermarket rear bars, even with smaller diameters than E93 M3, are solid vs. the hollow M3 bar, and thus much stiffer.

Thanks for the in depth reply. It looks like I have a ton of research to do as I know hardly anything about these suspension parts. Too many options really... Bottom line is with 19's I wonder if anything will improve my current ride and provide some comfort to be honest. Is all this really worth it?

[Gohan335i7]

Listen to Cal when he chimes in...

[RMNB]

Originally Posted by Gohan335i7

Listen to Cal when he chimes in...

I keep beating a dead horse...

[AtlasM]

Originally Posted by 550i Beast

Thanks for the in depth reply. It looks like I have a ton of research to do as I know hardly anything about these suspension parts. Too many options really... Bottom line is with 19's I wonder if anything will improve my current ride and provide some comfort to be honest. Is all this really worth it?

My car is actually pretty dang comfy with the stock suspension and same tire sizes as you. I'm running Kumho Ecsta PS91 tires with the pressure set to the factory 35/39 psi or whatever is listed on the door jamb.

Your ride could be bad for any number of reasons: heavy wheels, tires that just aren't comfy, too much tire pressure, worn shocks, worn shock mounts, bad sway bar end links, etc. I made sure to get relatively light weight wheels. Mine weigh 21-22 lbs, whereas most of the info I can find about Avant Garde wheels listed in your signature put them at 25-27 lbs depending on 19" size. That could be one of several factors.

I'm doing a whole pile of suspension stuff at the same time but on the most basic level you could stick with shocks, springs, and new strut mounts and bump stops. With the FSD + Eibach combo you can probably stick with the stock bump stops. I did the E36 M3/Z4 M bump stops because the B&G springs drop the car more than the Eibach springs.

I'm planning to do a thread going over all my stuff once it's on the car.

[RMNB]

Originally Posted by AtlasM

My car is actually pretty dang comfy with the stock suspension and same tire sizes as you. I'm running Kumho Ecsta PS91 tires with the pressure set to the factory 35/39 psi or whatever is listed on the door jamb.

Your ride could be bad for any number of reasons: heavy wheels, tires that just aren't comfy, too much tire pressure, worn shocks, worn shock mounts, bad sway bar end links, etc. I made sure to get relatively light weight wheels. Mine weigh 21-22 lbs, whereas most of the info I can find about Avant Garde wheels listed in your signature put them at 25-27 lbs depending on 19" size. That could be one of several factors.

I'm doing a whole pile of suspension stuff at the same time but on the most basic level you could stick with shocks, springs, and new strut mounts and bump stops. With the FSD + Eibach combo you can probably stick with the stock bump stops. I did the E36 M3/Z4 M bump stops because the B&G springs drop the car more than the Eibach springs.

I'm planning to do a thread going over all my stuff once it's on the car.

First off thanks for the detailed information! I appreciate it. This is info. I need to see as far as comparison and what the possibilities might be. When I get ready I will get with my Indy and see what he says as well and bounce ideas off him. I do have Conti DWS, air pressure correct but I don't know how the previous owner drove this car. A thorough inspection of the current suspension is definitely what I will have him check and go from there. I've had H&R on a previous F30 and the drop a little too much for me but it handled great! This is why the FSD/Eibach kit seems appropriate on the surface for now. Keep me posted when you get something else done as I would like to know the outcome.

[Jeff@TopGearSolutions]

Originally Posted by AtlasM

You can use any rear sway bar on the xi same as the rwd car, but UUC is the only company that makes a front sway bar for the xi. They're back ordered right now because they don't have any bushings in stock. I ordered a set before their site listed them as back ordered, didn't get any notification they were back ordered, and only learned this when I checked their order status page a few days later. Several calls to UUC resulted in no real answer on timeframe of when they would have the bushings made and no concrete reason for what was taking so long on the bushings being made. I canceled my order.

Instead, I'm doing Strongflex poly bushings and Ground Control adjustable end links on the stock front sway bar, and an E93 M3 rear sway bar with M3 bushings and Hotchkis end links. Both sets of end links are getting Seals-It rod end boots because they have exposed rod ends and I'm trying to keep them quiet. Well, the Hotchkis rear links have ball joints on one end of them, and the Seals-It boots come in a 6 pack which is the exact number of rod ends I'll have.

Replacing the rear sway bar requires dropping the subframe so if you do it, most folks also do subframe bushings at the same time. I went with Whiteline KDT917 bushings (not inserts).

These are all going on the car on Thursday along with Koni FSDs and B&G S2 springs, which drop the car a little bit lower than Eibach but otherwise mostly similar. I'm using E36 M3 front and Z4 M rear bump stops which are a bit shorter, to regain suspension travel and help the shocks do their job.

I chose the E93 M3 23.6 mm rear bar because with awd and staggered tires (I have 235/35-19 & 275/30-19 like you) I wanted more rear roll stiffness, but didn't want a radical increase in relation to the stock front sway bar. The aftermarket rear bars, even with smaller diameters than E93 M3, are solid vs. the hollow M3 bar, and thus much stiffer.

Im in the same boat with the UUC as you know. As a dealer, I was able to find out a little more details but still no firm ETA was available.

I'll stick with my order as the Xi REALLY need the sway bar upgrades in the front at a minimum.

I'm going to see how the front changes the car before I do the rear, plus the rear is a pain as you know.