[N8N]

Good morning all,

Long time since I've been here, but at 150K miles my stock suspension is slap wore out. E92, so I believe that's factory sport suspension. Just looking for something with a good ride and reasonable handling, and I'll need all the bushings/strut mounts/bump stops etc. as all those are completely gone as well. Last time I looked at this stuff I was thinking I would try Koni FSD but it appears that line has been discontinued. Any recommendations would be appreciated, and where to buy/package deals especially so. I live in MD near DC if that makes a difference. Thanks for any advice!

[Chapperss]

Did you forget how to use the search function during your time away? I know i`ve personally contributed to 4 or 5 similar posts in the last few months.

Koni Yellows or Bilsteins for struts - if you need springs to then you`ll have to search or wait for another kind sole to contribute.

It`s black friday time so i`m sure once you know what to shop for you`ll get a good deal somewhere.

[Spooly]

Depending on what you're going for you might be interested in the Bilstein b14's. Just had mine installed and I love them. Very OEM+ ride, I imagine its similar to how an M3 rides. Only potential downside is the front doesn't go up very high (little more than a one finger gap raised all the way up). They are also very affordable, got mine for ~$800 after shipping and Cali taxes.
Front is raised all the way up in this picture.

[MrFrizzzz]

Koni FSDs have been replaced by Koni special active dampers. I’ve just installed these on my E91 and although the rears were completely shot, these have made a definite improvement. Can’t really compare them to anything else though. Would have probably gone for something like the B14’s but my car is a daily and I do a lot of motorway miles so didn’t really see the point.

[N8N]

Originally Posted by Chapperss

Did you forget how to use the search function during your time away? I know i`ve personally contributed to 4 or 5 similar posts in the last few months.

Koni Yellows or Bilsteins for struts - if you need springs to then you`ll have to search or wait for another kind sole to contribute.

It`s black friday time so i`m sure once you know what to shop for you`ll get a good deal somewhere.

Gee, I didn't know that civility had become a lost art.

Does anyone have anything USEFUL to contribute?

and no, yellows are not what I'm looking for, I've had them on several cars before and I've had to run them full soft on the bombed out roads we have in the metro DC area. Not looking for sporty but practical. I'm running 17" wheels from a 328i as well for similar reasons; I got sick of spending so much money at Ye Old Wheel Shoppe (actual name of the place in Elkridge, MD) on repeated wheel repairs.

My request is not what most E9x owners are going for, hence yes, I have searched, however before I buy anything I'm looking to see if anyone has tried any of the currently available products in a similar situation to mine.

I also am getting confused as to what installation parts I need as my understanding is all US E92s had "sport suspension" and a lot of stuff that vendors sell that "fits" my car says "standard suspension". Also not sure what changes in that regard if I use aftermarket e.g. Koni or Bilstein struts.

[N8N]

Originally Posted by MrFrizzzz

Koni FSDs have been replaced by Koni special active dampers. I’ve just installed these on my E91 and although the rears were completely shot, these have made a definite improvement. Can’t really compare them to anything else though. Would have probably gone for something like the B14’s but my car is a daily and I do a lot of motorway miles so didn’t really see the point.

Ah got it. I'm kind of leaning toward that then. How do you find them on potholed roads? Do you have sport suspension? Thanks for the reply.

Another option would be a Bilstein strut kit. I'm inclined to just reuse my stock springs as I have no desire to go "sportier" and the car is already borderline too low even though I've upsized my tires.

[MrFrizzzz]

Originally Posted by N8N

Ah got it. I'm kind of leaning toward that then. How do you find them on potholed roads? Do you have sport suspension? Thanks for the reply.

Another option would be a Bilstein strut kit. I'm inclined to just reuse my stock springs as I have no desire to go "sportier" and the car is already borderline too low even though I've upsized my tires.

Yeah definitely more comfortable on crappy roads but definitely better round corners and roundabouts now. But once again don’t know if that’s just cause the old shocks were knackered. And yeah I’ve sports suspension running 18” wheels and kept the standard springs. Was debating going Eibach pro springs but because it’s a daily and have to drive over a fair few speed bumps I kept with standard springs. I’d say all in it’s a worthwhile upgrade for the money. Think I paid about £450 for the 4 dampers and fitted them myself.

[lowrydr310]

Originally Posted by N8N

Just looking for something with a good ride and reasonable handling, and I'll need all the bushings/strut mounts/bump stops etc. as all those are completely gone as well.

If you're not doing autocross or track time, save some money and just get the Bilstein B4 OEM equivalent. I just ordered a set for my E90 with sport suspension and I'm keeping the stock springs. They're half the price of the B8 struts and rear shocks.

The bump stops are specific to sport/non-sport struts and shocks so keep that in mind when shopping.

[N8N]

Originally Posted by lowrydr310

If you're not doing autocross or track time, save some money and just get the Bilstein B4 OEM equivalent. I just ordered a set for my E90 with sport suspension and I'm keeping the stock springs. They're half the price of the B8 struts and rear shocks.

The bump stops are specific to sport/non-sport struts and shocks so keep that in mind when shopping.

Ugh. you just brought something up that I guess needs to be revisited, and I thought that I had sorted.

I purchased the Koni Special Active struts just Monday from ECS Tuning, and I have the install material and bump stops sitting in my cart that I plan on ordering when I get paid on Friday.

Is it only the bump stops that are different?

Would the Koni Special Active struts be considered "sport" or "non sport"?

Which bump stops would I need? (if you're just going to look them up on realOEM just say so, no need to waste your time looking up something that I could do myself.) I have 31302405872 and 33536767335 sitting in my shopping cart right now but they don't appear to specify sport or non sport.

thanks...

[MrFrizzzz]

Originally Posted by N8N

Ugh. you just brought something up that I guess needs to be revisited, and I thought that I had sorted.

I purchased the Koni Special Active struts just Monday from ECS Tuning, and I have the install material and bump stops sitting in my cart that I plan on ordering when I get paid on Friday.

Is it only the bump stops that are different?

Would the Koni Special Active struts be considered "sport" or "non sport"?

Which bump stops would I need? (if you're just going to look them up on realOEM just say so, no need to waste your time looking up something that I could do myself.) I have 31302405872 and 33536767335 sitting in my shopping cart right now but they don't appear to specify sport or non sport.

thanks...

The part number I have for the rear bump stop is 33506773629 and that’s what I ordered from the motor factors. The part number you have for the fronts looks fine. These are fitted to my 35d with sport suspension and koni dampers and it drives just fine.

[N8N]

I got the following reply from Koni when I asked:

Thank you for contacting us here at KONI NA. Yes, you will need to reuse your factory OE bumpstops for replace those stops when installing the KONI Special ACTIVE dampers. It is recommend to use the factory bumpstop, thus it will depend on whether you have the factory equipped sport suspension or not. If using a lowering springs I would suggest the Sport suspension stops.

So, does this mean that the only difference between standard and sport bump stops is height and/or durometer?

I guess if they both fit I will just look up the parts on realOEM and make sure I get the sport ones. Or I have heard of times where bump stops have been used as progressive springs... would it make sense to use taller standard ones? oh no another rabbit hole

Per RealOEM:

front bump stop is 31336767333 "additional shock abosrber, front" but that is just the bump stop only (for sport suspension; w/o sport suspension is 31336771352)

boot is 31331094749 "protection tube"

Part no. 31302405872 on realOEM appears to be "Repair kit, additional damper guard tube" appears to be bump stop and boot, for whatever reason description is misleading, says rear but appears to be front. 31302405874 is the same part for standard suspension.

for the rear, the sport suspension bump stop that appears to come with the tube ("auxiliary shock absorber, rear") is 33536767335, standard suspension is 33536767334

so I think I see what I'm going to order tomorrow (basically stock replacement parts for "sport suspension"); do you think I should order any kind of camber plate with my order? I do have M3 strut rods but otherwise car is 100% stock.

[Tambohamilton]

Yes, length and rate are the only difference between sport and n/s bump stops. They will both physically fit with sport or n/s struts/shocks/etc.

Generally, you should use shorter and/or softer bump stops if you want comfort. I know that sounds counterintuitive, but it's true (within reason). BMW actually calls the bump stops 'auxiliary springs', because they're there to ramp up the spring rate fast when the suspension is compressed beyond ride height. The bump stops are actually engaged at ride height in a stock setup. This is to give a degree of compliance and a degree of body roll resistance...you could argue that the stock setup does neither sufficiently well! So if you want to increase comfort (at the expense of some body control), you should soften or shorten the bump stops. Any stock bump stop (eg E36 M3 fronts) will perform the traditional duty of a bump stop sufficiently well. However, you should be very careful with bump stop tuning, because they can have a huge effect on chassis balance (understeer/oversteer characteristic). What's the correct answer? How long is a piece of string?

[whyzee125]

I like koni str.t. Lifetime warranty with any springs, firm enough to not be bouncy with lowering springs, and theyre cheap. Autohance has them for like $370 shipped for all 4 rn

[N8N]

Originally Posted by Tambohamilton

Yes, length and rate are the only difference between sport and n/s bump stops. They will both physically fit with sport or n/s struts/shocks/etc.

Generally, you should use shorter and/or softer bump stops if you want comfort. I know that sounds counterintuitive, but it's true (within reason). BMW actually calls the bump stops 'auxiliary springs', because they're there to ramp up the spring rate fast when the suspension is compressed beyond ride height. The bump stops are actually engaged at ride height in a stock setup. This is to give a degree of compliance and a degree of body roll resistance...you could argue that the stock setup does neither sufficiently well! So if you want to increase comfort (at the expense of some body control), you should soften or shorten the bump stops. Any stock bump stop (eg E36 M3 fronts) will perform the traditional duty of a bump stop sufficiently well. However, you should be very careful with bump stop tuning, because they can have a huge effect on chassis balance (understeer/oversteer characteristic). What's the correct answer? How long is a piece of string?

I have heard previously of relying on bump stops to provide progressive springing. I did not realize, if you are correct (I will look once the last corner is back on the ground - I did three corners over the weekend and did not finish yesterday as it was raining all day), although given what I'm seeing I have no reason to disbelieve you, that the bump stops are actually engaged at normal ride height. However, that would explain why everyone always asked me if I'd lowered my car (I hadn't; the one and only suspension mod was M3 strut rods when the originals wore out) and definitely at some point in the vaguely recent past the suspension on my car went from feeling a little underdamped to completely crashy and super loose. That's what prompted this exercise... well it turns out that only the driver's side front strut had anything resembling a bump stop on it. I'm guessing that's the only corner that had any damping left as well; I haven't taken the passenger side strut off yet but it looks the worst, with no bump stop at all, not even a little ring of busted foam left, and oil running down the housing. Both rears had minimal damping as well when I got them off (none had any residual gas pressure, or at least not enough to overcome seal drag), and both rear bump stops were 80% MIA.

I'm actually looking forward to driving this once I get it back together; hopefully this will wind the clock back a bit in terms of handling.

Things that I've learned:

1) BMW likes making you use All The Tools. I actually had to use Torx (cargo hooks in the trunk), E-Torx (rear lower shock mounts) and Allen sockets (shock shafts, upper and lower for rear and upper for front.)

2) You need to compress the front springs by the upper spring seat. There is no other way to get them off the struts.

3) related to above, I needed an impact gun and vice-grips (that's mole grips to you limeys) to get the upper front nut off.

4) Whoever told me to buy a pass through socket set was on point. I don't think I could have done this job without it. Even if I'd used stock Sachs struts, the old and new BMW upper nuts (I bought the whole installation kit) were different sizes and the Koni nut was a different size yet. A long length Allen bit socket would have been good for installing the strut bearings, although with the flex handle pass through ratchet I was able to get it done without.

5) the Koni front struts are way longer extended than the stock E92 (in the US, that automatically means sport suspension) front struts (more droop) so Sunday I found myself in a bit of a bind as I had not removed the tie rod end from the knuckle and suddenly my strut assembly was about 3/4" too long to fit under the fender lip. WHOOPS. TRE nut laughed at my M18 Fuel impact driver. No way to remove using hand tools with no strut attached. Ended up re-compressing the spring and then having the fun exercise of removing the spring compressors with the strut half installed and under the fender. Good times good times. At least I didn't have to re-install the old front strut and then disassemble it again to transfer the spring over.

6) related to 2) and 5) above, my old Harbor Freight spring compressors did not work. I had to use the loaners from Advance which appear to be the Powerbuilt branded version of OEMTOOLS 25553.

[MightyMouseTech]

Originally Posted by lowrydr310

If you're not doing autocross or track time, save some money and just get the Bilstein B4 OEM equivalent. I just ordered a set for my E90 with sport suspension and I'm keeping the stock springs. They're half the price of the B8 struts and rear shocks.

The bump stops are specific to sport/non-sport struts and shocks so keep that in mind when shopping.

Installed B4 in my E90. Very happy with them.

[tlow98]

Originally Posted by Chapperss

Did you forget how to use the search function during your time away? I know i`ve personally contributed to 4 or 5 similar posts in the last few months.

Koni Yellows or Bilsteins for struts - if you need springs to then you`ll have to search or wait for another kind sole to contribute.

It`s black friday time so i`m sure once you know what to shop for you`ll get a good deal somewhere.

You've certainly contributed to this thread. I thought the lobstahs were on the polite side? Not today I guess.

Originally Posted by MightyMouseTech

Installed B4 in my E90. Very happy with them.

This is what I would recommend based on what you have mentioned. eBay has these full kits for like $250 shipped. Incredible.

[N8N]

So not that I had any reason to disbelieve Tambohamilton but at least for the fronts he is correct; I just put everything back together and then took a little drive to Advance to return the spring compressors and settle the suspension. My driveway has a *slight* slope to it so the car is sitting slightly nose down, but for sure, the fronts are sitting on the bump stops at rest with stock E92 springs and "sport suspension" bump stops. The rears I can't feel because I can't get my arm around the tire without lifting the car.

so, today I learned something... now why did BMW choose to do it this way? I dunno. I suspect the disintegration of my pass front bump stop contributed greatly to the demise of the strut... Both rears were pretty much missing as well.

Even without an alignment the car feels like a completely different vehicle. As in, not a POS.

[Tambohamilton]

It's actually completely standard in passenger cars, using a long bump stop sort of as a tender spring. It allows the boffins to inexpensively create a progressive (rate increases with bump) wheel rate, which allows a better (or at least, tuned/tunable) balance between comfort and body control. But it also hugely affects 'magic number', which is the ratio of front roll rate to total roll rate... Most manufacturers will use it so that in docile driving (low speed cornering) the car has very neutral handling, but the harder you turn (and therefore the greater the body roll) the higher the magic number, which results in greater understeer. So it gives the effect of very predictable, progressive understeer.

But yeah, disintegrating bump stops will make your car feel like crap!

[N8N]

Originally Posted by Tambohamilton

It's actually completely standard in passenger cars, using a long bump stop sort of as a tender spring. It allows the boffins to inexpensively create a progressive (rate increases with bump) wheel rate, which allows a better (or at least, tuned/tunable) balance between comfort and body control. But it also hugely affects 'magic number', which is the ratio of front roll rate to total roll rate... Most manufacturers will use it so that in docile driving (low speed cornering) the car has very neutral handling, but the harder you turn (and therefore the greater the body roll) the higher the magic number, which results in greater understeer. So it gives the effect of very predictable, progressive understeer.

But yeah, disintegrating bump stops will make your car feel like crap!

This is all new to me... the way I'm used to seeing this effect done is with a progressive rate spring where either the spring is wound, or two separate springs are used (usually in a coilover setup), where at ride high the "soft" section is either at or near coil bind and then the 2-3 coils of the stiff spring take over. Then at droop, the soft spring keeps the springs from unseating and ruining everything.

It appears that instead on an E9x the entire spring is "soft" and the bump stop is used instead. Granted I'm way behind on current suspension thinking, but I think for longevity in daily use I would prefer the older setup that I describe above...

Also, what this says to me is that an E9x even unlowered only has maybe 1.5" of compression travel?

[Tambohamilton]

Be mindful of the difference between helper spring and tender spring.

Yep, something like 1.5-2" of useful bump travel. About 4" of droop travel.

[N8N]

right, just for reference this is likely the exact same spring kit that was my very first suspension upgrade (with some Koni Yellows) back in the day.

https://www.ecstuning.com/b-h-and-r-...ing-set/54743/

Paired that setup with some poly LCA bushings and some 15" Borbet Type Cs with 50 series tires. That was pretty aggressive stuff back in the day... now my "downgrade" wheel/tire package (in an attempt to actually wear out tires rather than just blowing them out on potholes) on my E92 still has smaller sidewalls... but I digress.

Also, I'm getting old... that suspension was on my old faithful '84 'roccet and i loved it, but if I had to commute with that today I'd be looking for a cheap used beater car. Oh, wait, that's my Jeep XJ. (really a far more practical commuter near DC than any VW or BMW)

[culto]

Originally Posted by N8N

Good morning all,

Long time since I've been here, but at 150K miles my stock suspension is slap wore out. E92, so I believe that's factory sport suspension. Just looking for something with a good ride and reasonable handling, and I'll need all the bushings/strut mounts/bump stops etc. as all those are completely gone as well. Last time I looked at this stuff I was thinking I would try Koni FSD but it appears that line has been discontinued. Any recommendations would be appreciated, and where to buy/package deals especially so. I live in MD near DC if that makes a difference. Thanks for any advice!

I installed Bilstein B4s and Myle HD control arms in my 2011 328ix and I love the combination.