Needing Advice on Rear Suspension Refresh

[Bludsport]

I've got everything I need for the front, but the rear is a little more complicated for me. I'm not at all familiar with this model BMW, it's strengths and more importantly it's inherent weaknesses. Besides the new shocks struts I just bought from AST, which seem to be a great deal and I hope I like, I'm not completely certain of exactly what stuff I should change when it comes to the rear end. So far, this is what I had planned to do:

+Replace the rear upper and lower control arm bushings
+Replace the lower control arm with an adjustable one because it looks so cool!
+Replace the trailing arm joints/bushings
+Retain the OEM rear sway bar and only replace the bushings

There's a ton of options out there, so I'm a little vexed. "BMW Curves" idea of a "OEM+" result seems like a good and reasonable idea, but I do want to improve handling where I can without incurring too much NVH in the process. A reasonable amount of NVH is an okay tradeoff for me when it comes to handling, but not so much that my car rides like it's on steel tires.

I hadn't intended on getting into the rear axle carrier stuff unless you guys think now is a good time to do so since I'll be back there anyway and since my car has 69K miles on it.

So, with that said, I sure could use some advice on what parts to use and the best places to get them.

In case any of you are looking to replace your OEM shocks and struts in the near future, I'd like to mention that working with Sean Meyers at AST Suspension was an absolutely great experience. He went out of his way to answer my questions, handle the sale, send me photos, send me tech details and guide me through the whole process from his cell phone while in the middle of catching flights and traveling. This new setup by AST, the 2100 Series, seems like a great compromise between choosing shock/struts and coil-overs and IMO, it's reasonably priced at $1,299.00. AST is in the process of revamping it's website so there's not much info there on this series, but here are the photos Sean sent me of the stuff he's sending out to me on Monday.

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[slater]

that's certainly an interesting photo they sent, because they've got the rear springs on the front dampers. not very confidence-inspiring.

[BMWCurves]

that's certainly an interesting photo they sent, because they've got the rear springs on the front dampers. not very confidence-inspiring.

Are you sure? What are the springs to the right of the image next to the rear shocks?

[slater]

Are you sure? What are the springs to the right of the image next to the rear shocks?

they are the front springs, which are linear-rate and appear to have the same ID top and bottom.... whereas the rear springs do not; also they are barrel-shaped like the stock rear springs to allow articulation with the non-parallel spring perches of the E46 rear suspension.

also, the 'VMAXX' endlinks appear to come from a dutch manufacturer of 'xxtreme lowering' coilover kits.... hoo boy.

it just really rubs me the wrong way. there's no way i would buy AST suspension based on this photo.

also... post #4000. :cheers

[Bludsport]

they are the front springs, which are linear-rate and appear to have the same ID top and bottom.... whereas the rear springs do not; also they are barrel-shaped like the stock rear springs to allow articulation with the non-parallel spring perches of the E46 rear suspension.

also, the 'VMAXX' endlinks appear to come from a dutch manufacturer of 'xxtreme lowering' coilover kits.... hoo boy.

it just really rubs me the wrong way. there's no way i would buy AST suspension based on this photo.
also... post #4000. :cheers

Ha! The pics were sent to me by one of AST's salesman from his hotel room. Good thing he's in sales and not a tech. No problem with the VMAXX end links, Im not going to use them anyway. The sway bar I bought from Ground Control comes with GC end links.

Anyway, thanks for all the criticism and not even addressing one my original questions.

[sillieidiot]

It's cause slater is elite jk lol

Anyhow, just go OE for everything. Just doing that would already upgrade your handling/ride quality if all your bushings were bad. Then you're also getting coilovers so you'll get better handling from that as well. You'll get a lot more NVH when you go with polys for sure. Most people that upgrade from bad bushings to polys say it doesn't increase NVH because their bushings weren't working correctly in the first place.

edit: saw your other thread with the fronts. seems like you're fine with a fair amount of NVH. Although for most of the things you listed OE would be fine. For the RTABs maybe try the bimmerworld ones, the one with the sealed bearing. I've read good things about it. What adjustable control arms are you looking at?

[slater]

Ha! The pics were sent to me by one of AST's salesman from his hotel room. Good thing he's in sales and not a tech. No problem with the VMAXX end links, Im not going to use them anyway. The sway bar I bought from Ground Control comes with GC end links.

Anyway, thanks for all the criticism and not even addressing one my original questions.

yowza... passive aggressive much? :cheers i wasn't criticizing you, but AST. even the salesguy should know how the product well enough to put the right springs in the right places.

for parts - at 69K miles, i'd do RTABs and the rear outer control arm bushings. go OEM M3 for the outer control arm bushings, and i would highly recommend the bimmerworld sealed spherical RTABs. everything else is a compromise. ECS or FCP is my go-to for parts like that.



It's cause slater is elite jk lol

LOL. i'm OK with "picky", but "elite" is not what i aim to come across as. whoops.



Then you're also getting coilovers so you'll get better handling from that as well.

i disagree with this - it's a conditional statement. you can achieve better handling if:

a) the coilovers have well-spec'd spring rates and damping, and;

b) you don't lower the car much.

you can absolutely make handling worse if either, or both, of those two points are missed. the stock springs in particular are pretty darn good.

yep. picky. :cheers

[sillieidiot]

yowza... passive aggressive much? :cheers i wasn't criticizing you, but AST. even the salesguy should know how the product well enough to put the right springs in the right places.

for parts - at 69K miles, i'd do RTABs and the rear outer control arm bushings. go OEM M3 for the outer control arm bushings, and i would highly recommend the bimmerworld sealed spherical RTABs. everything else is a compromise. ECS or FCP is my go-to for parts like that.




LOL. i'm OK with "picky", but "elite" is not what i aim to come across as. whoops.




i disagree with this - it's a conditional statement. you can achieve better handling if:

a) the coilovers have well-spec'd spring rates and damping, and;

b) you don't lower the car much.

you can absolutely make handling worse if either, or both, of those two points are missed. the stock springs in particular are pretty darn good.

yep. picky. :cheers

well b) is also dependent on your roads too. you can definitely go lower if they are super smooth.

nah elite sounds better lol picky didn't have enough pizzazz :p

[slater]

well b) is also dependent on your roads too. you can definitely go lower if they are super smooth.

nah elite sounds better lol picky didn't have enough pizzazz :p

hahaha.... :cheers

re: the smooth roads... perhaps, but you're still compromising on suspension travel and optimal geometry if you lower too much. everything is a compromise. :)

[Bludsport]

yowza... passive aggressive much? :cheers

HA! Not by nature, I suppose it's a bad habit I picked up from my ex...the absolute queen of passive aggressive!
Like you, I am by nature very picky, and sometimes it rubs people the wrong way, so I get it.

I've been driving my car a for a while now and it seems to me that it's in dire need of a suspension refresh. Turning in on corners with any bumps or ruts isn't a very pleasant experience. It's got a set of Pilot Super Sports on it with a good bit of tread left, but they're a little old so I'm going to replace them after the suspension work is completed. I think using stock parts is a good idea, but I tweaked things a little and hopefully it will make for a good compromise between comfort and handling.

AST is a strange company. They have little to no technical information on their various websites, so I have no idea what the spring rate is on the springs they sent me, nor do I know what the preset on the front coil-overs is supposed to be. i sent an email to the rep I bought them from at AST asking him if AST had any specific instructions or information on settings I should know about, and he told me: "This is not a DIY type of thing. Get a professional to do it and they will know." Well...excuse me. Guess I'll just have to wing it and see how they work out. I seriously doubt they could make things any worse.

Anyway, here is a list of the parts I chose to use:

FRONT:
+ AST coil-overs
+ Rogue FCAB's (street compound)
+ OEM ZHP control arms
+ OEM tie rods
+ OEM strut mounts
+ Strut reinforcement plates
+ OEM rubber steering rack boots
+ Adjustable sway bar links compliments of AST

REAR:

+ AST springs and shocks
+ Rogue shock mounts (street compound) with reinforcing plates
+ OEM lower control arms with OEM outside bushings
+ Rogue RTAB's (street compound)
+ RTAB limiters from ECS Tuning
+ OEM RTAB bushings and ball joints

Hopefully with all the above installed, new tires and a good alignment, the ride and handling will improve. If not, I'm selling it!
As far as lowering goes, I plan on about 1" to 1.5". God knows you can drop a ton of money into suspension mods, but for a street car that's 11 years old, I've reached my limit on the suspension.