[wren57]

New job has me driving 1k miles/week. Am now more interested in a smooth ride than rail handling. Have the BMW performance shocks now but they have about 50k on them and are a bit rough for my 19" wheels. I'm switching to 18s and want to swap out my shocks as well. Been out of the game for a while so looking for suggestions.

Thanks!

1K miles a WEEK?!@?!?

Sell it and buy Prius.

[Chrispy650]

Damn. 1k a week...plan on moving closer to the new job? Lol

[wren57]

Car is paid for, has 110k miles, and has some cosmetic damage on the front bumper/hood, so it's not worth a whole lot. Worth more to me since I have done all my own maintenance and it runs like a top. Just going to drive it into the dirt. I get mileage reimbursed 57.5 cents a mile, going to save those checks and get a new car once this one craps out. Besides, 27mpg isn't too shabby. Would like a smoother ride tho.

[e90ca]

dang, thats a lot of miles each week!! must be tiring!

[Tom Droze]

Koni FSD shocks will provide good ride comfort and decent handling. I have the Koni FSD SHOCKS paired with the Eibach Pro Kit springs and the ride comfort changed very little from stock.

Originally Posted by Tom Droze

Koni FSD shocks will provide good ride comfort and decent handling. I have the Koni FSD SHOCKS paired with the Eibach Pro Kit springs and the ride comfort changed very little from stock.

That's not saying a whole lot given that the stock ride quality on these cars is terrible; largely a result of underdamped suspension IMO.

[Tom Droze]

Originally Posted by FCobra94

That's not saying a whole lot given that the stock ride quality on these cars is terrible; largely a result of underdamped suspension IMO.

Instead of criticizing a post, why not try and provide some level of useful feedback in response to the OP's question?

The fact of the matter is, the underdamped suspension is only really evident when the car is driven in a spirited manner. The Koni FSD shocks maintain the same OE ride quality (for commuting purposes) the OP is seeking while providing improved damping when the car is driven in a spirited manner.

[gunnerxq]

Originally Posted by Tom Droze

Instead of criticizing a post, why not try and provide some level of useful feedback in response to the OP's question?

The fact of the matter is, the underdamped suspension is only really evident when the car is driven in a spirited manner. The Koni FSD shocks maintain the same OE ride quality (for commuting purposes) the OP is seeking while providing improved damping when the car is driven in a spirited manner.

Ehh it's probably his spacers and his questionable choice of tires. I mean come on DWS with a dedicated winter tire? at least get the DW but then still.

But I would go with the B8 bilstein shocks/struts with Eibach pro-kit. Don't forget to get the sports suspension shock mounts since they are sturdier. And all the rubber pieces that support your struts/springs/shocks since these will go towards increasing ride comfort.

Edit:Or the B-12 Pro-kit

Originally Posted by Tom Droze

The fact of the matter is, the underdamped suspension is only really evident when the car is driven in a spirited manner.

Not true at all. Whether you're driving in a spirited manner or not, bouncing off the bump stops on average quality roads/expansion joints and feeling like you're about to fly out of the car when going over large dips is a direct result of underdamped suspension. If the only thing you change is a proper set of dampers and the problem goes away, guess what? Your shocks/struts just aren't up to the task; stock or not. An ill tuned suspension will show it's foibles the second you back out of your garage. It can happen with rock hard run flats or super soft/squishy winters (all of which I have direct experience with) and lol no; this has nothing to do with spacers.

AS for my useful feedback, plenty of peeps on here have complained that FSDs aren't consistent and just don't perform the same over time, pointing to the fact that they're most likely underdamped and are more similar to stock than anything else (not necessarily a good attribute to have). Those same members have switched to Bilsteins/Konis with much better results. You don't need me to tell you that, just use the search button.

[Tom Droze]

Originally Posted by FCobra94

AS for my useful feedback, plenty of peeps on here have complained that FSDs aren't consistent and just don't perform the same over time, pointing to the fact that they're most likely underdamped and are more similar to stock than anything else (not necessarily a good attribute to have). Those same members have switched to Bilsteins/Konis with much better results. You don't need me to tell you that, just use the search button.

I did use the search function prior to making a decision as to what shocks to buy; and as I stated earlier, I have the Eibach springs and the KONI FSD shocks. While there have been complaints relative to the FSD shocks, one also has to take into account the manner in which the car is being used and driven, and the driving skill level of the person providing the review. Are the FSD shocks for everyone? No. Are there better shock options than the Koni FSD shocks for people who drive their car hard or do track days? Yes there are. But with that said, the Koni FSD shocks are a good plug and play option for people who want reasonable ride comfort with improved handling. With where I am at today with my car would I still buy the Koni FSD shocks if I was making a purchasing decision today? probably not; but at the time of my purchase, I never envisioned doing track days with my car either. But I will say this, through several spirited driving trips with the local BMW club and two track days, the Koni FSD shocks have performed well and have done so over the last year. Additionally, both instructors I had for my track days commented on how neutral my car felt and that they were very impressed with the suspension set up that I have.

Oh, and Since the OP was most interested in ride comfort over anything else, and since I have first hand experience with the Koni FSD shocks, I recommended them.

[emapway]

Bilstein shock would be great combo with your Eibach springs. Had the same combo all bought from 4 Wheel Online. Ride comfort was great, but the stance is sexy and gorgeous.

[udm328i]

Call eibach direct and get shocks, I bought pro kit that came with shocks, they had a eibach sticker but you can see bilstein metal stamp on them.

[swagon]

Bilstein B8. Actually Eibach springs come with B8's in a kit as Bilstein B12.

[udm328i]

Originally Posted by swagon

Bilstein B8. Actually Eibach springs come with B8's in a kit as Bilstein B12.

Shock is tuned perfectly to the spring, so it's B8? The kit I bought was called eibach pro system, but didn't give any specs on the shock

[steifan]

Originally Posted by udm328i

Shock is tuned perfectly to the spring, so it's B8? The kit I bought was called eibach pro system, but didn't give any specs on the shock

I bought a Eibach/Bilstein Pro-kit B12 from Germany (live in Sweden) to my E46 and it was bigger box with Eibach & Bilstein logos which contained a box of Eibach pro-kit springs and four boxes of Bilstein B8 struts and shocks. I checked the article no and they were just B8 Sprints so nothing special really, more than being sold as a kit. In a box.

[swagon]

There has been info that the B8's in the B12 kit are revalved to the springs. Whatever, I'll email Bilstein.

[steifan]

Originally Posted by swagon

There has been info that the B8's in the B12 kit are revalved to the springs. Whatever, I'll email Bilstein.

Anyways the B8's in the B12 package carried the same article number as the normal B8 Sprint. One would think that a revalved product would have another article number. But that's only what I saw on E46 stuff, might be different with others perhaps (but probably not).

[shirtpants_]

Whats your average speed? Are you usually on the highway?
I don't know how "comfortable" different shocks are, but I can give some insight on the spring rates, which is just as important.

You want the suspension frequency of
both the front and rear to be above 1.1 Hertz and below 1.5 Hertz,
this is widely accepted as the most comfortable range.
Above 1.5 our bodies interpret the motion as too harsh(generally),
and below 1.0, we usually get some kind of moderate motion sickness from the oscillation.
You also need the Frequency of the front to be slightly lower than the frequency of the rear.
This means that when the car goes over a bump, the front and rear will settle at about the same time.
This is called a flat ride.

You can have very soft springs, and compliant dampers, but if the frequency bias isn't optimized, and they don't produce
a flat ride, then you wont interpret it as comfortable. Or at least it wont be as comfortable as it could be.

For example, (these are just random #'s btw)
Frequencies of 1.2 Hertz for the front, and 1.3 Hertz for the rear,
you will get a flat ride at a 55 MPH.
But with frequencies of 1.35 Hertz for the front, and 1.4 Hertz for the rear,
you will get a flat ride at 75 Mph.
You can change the spring rates, yielding different frequencies, which change the speed that you can get a perfectly flat ride at.

If you're interested in figuring this out,
let me know and I can help out(there's alot of formulas).
I haven't gotten new springs/dampers yet, but I have done the math for my car, and I know what I need to get.
Although comfort wasn't really my priority.

[wren57]

Wow that's technical. I normally cruise at about 78-80mph on the interstate.

[shirtpants_]

Originally Posted by wren57

Wow that's technical. I normally cruise at about 78-80mph on the interstate.

I can't find my formula for flat ride in relation to speed, but I have my notes of what the e92 m3's flat ride is.
Front: 1.31 HZ
Rear: 1.49 HZ
Flat ride is optimized at 67 MPH
Ill put up an update if can find the right set of notes with the flat ride speed formula on it.

[shirtpants_]

Ok, I can't find my formula, but I found what I calculated to be a flat ride at 79.5 mph. (for my car, a e90 335i)
It was
Front: 1.536 Hertz, or 92.16 Cycles per minute (CPM)
Rear: 1.697 Hertz. or 101.8 CPM
Don't know if this was right, its just what I found in my notes
I think the magic number for a flat ride at that speed was having a front frequency or CPM that is 9.5% lower than the rear.
Cycles per minute is just Hertz*60.

If you want this to be extremely accurate, you need to have your car cornerbalanced, and weighed with you in it, along with finding the front and rear sprung and unsprung rates. I used my baseline weights from someone else who already had this done.