chknhwk
chknhwk Dork
3/3/24 8:13 a.m.

Good morning all - the time has come to replace the suspension on Moby Dick! (Yes, I named my white wagon Moby Dick...)

2007 328xi E91 BMW

My plans are to run 17x9" +30et wheels with 245/40-17's in the summer with a dedicated winter wheel/tire combo. I enjoy HPDE's with occasional autocross (I feel track time is better in an HPDE) so looking for something a little more aggressive than 225's. I don't want to go up to 18's. I will most likely run Nitto's (NT555) or Toyo's (Proxes) because i would like my treadwear rating to be around 300-320. 

Issues: Apex Wheels told me I may have to run a little extra negative camber up front and/or roll my fenders to compensate for the wider tires and the B14's will only exacerbate that. I don't think I want the adjustability of coilovers (I'm not into the slammed/stanced look anyway) but the B12's appear to be backordered everywhere. 

Question: How much are the B14's going to impact how much front tire I can put on the car? I always run square setups for ease of rotating. How much negative camber/fender rolling will I need? Is the performance aspect worth it to just go with the B14's? I live in Massachusetts so ride quality is a thing... 

Appreciate any and all input! 

02Pilot
02Pilot PowerDork
3/3/24 8:24 a.m.

Is there a specific reason for Bilsteins over Konis? I had Bilsteins on my 128i and ripped them out because 1) they were rusting badly, a problem I've had with multiple recent Bilstein products (and not covered by warranty), and 2) they were pretty harsh. This car also has the 1M/M3 control arms and Eibach springs; if you're doing HPDE, I'm guessing you have similar upgrades. I'm much happier with the Konis in every respect.

chknhwk
chknhwk Dork
3/3/24 8:58 a.m.

In reply to 02Pilot :

Interesting - all the research I've done on this points to the Konis rusting out MUCH more than the Bilstein's. You're the only one that has said anything counter to that. That, coupled with the experience I've had with Bilstein's on my Jaguar, makes me a return customer. I WAS seriously considering the Koni FSD's after reading about them but the E90 boards were pretty much in agreement the Bilstein's were a superior product. 

These and the wheels (other than slotted brakes) will be my first upgrades. 

02Pilot
02Pilot PowerDork
3/3/24 9:50 a.m.

In reply to chknhwk :

That is interesting. I had a problem with the Bilsteins rusting at the top of the shaft, just below the upper strut bearing, on both my E39 and E82. The E82 rears started to rust around the base of the body as well. So far no signs of rust on the Konis, but I'll check again when I pull the snow tires off in a few weeks. As far as ride, IMO the Koni Sports are an order of magnitude more pleasant than the Bilsteins were; I did not track either car, so I can't speak to track performance, but in your usage I'd be looking at the Sports (which are adjustable), not the FSDs.

As far as other upgrades, definitely do the rear subframe bushing inserts - they transform the way the car feels. Without them, it feels like the front and rear are in different time zones. The control arm upgrade is totally worth it as well, especially for the extra camber you'll get up front. I'm mixed on the Eibachs for street use - they're right on the edge of too stiff for the roads around here; on smooth pavement they're great. I might actually pull them out to go with the less aggressive H&R OE Sports.

chknhwk
chknhwk Dork
3/3/24 10:57 a.m.

Why would you recommend the Koni Sports over the FSD's?

Are you talking the M3 front arms? I thought they didn't work on the AWD platforms? At least that's what Turner Motorsports told me when I was looking at their upgrade kit... 

I'll definitely look at the rear inserts. 

02Pilot
02Pilot PowerDork
3/3/24 12:28 p.m.

Sorry, I'm probably wrong about the control arms - I don't speak AWD BMW. Sports over FSDs is based on what I was told here when I was asking about it a few years ago. I'll see if I can find the thread later, but basically it was that the FSDs are a compromise, IIRC.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
3/3/24 12:42 p.m.

FSDs are an interesting shock that needs travel to work well. They're good on a Tesla Model 3, not so much on an NA Miata due to the short rear travel. But regardless, they're intended for stock springs.

I would also use Koni over Bilstein. I've rarely been happy with the damping quality of Billies. 

Shaun
Shaun Dork
3/3/24 2:24 p.m.

I ran Bilstein and Konis on the same car and I did not like the compression rate the Bilstein's added- particularly to get them moving.  I am stuck with Bilsteins on a Volvo V70R because Koni does not make the fronts- now that they are 4-5 years old the bashiness has subsided bit but still meh.   I really really like how Koni Sports work.   The paint on the three sets of Koni sports I have bought was coming off before they even went on the car.  So the tubes have some superficial rust, but I do not think it matters... where I live which is salt free.

chknhwk
chknhwk Dork
3/3/24 2:29 p.m.

Well this conversation didn't go the direction I thought it would. 😂😂

IF I go with the Koni Sports what springs should I go with, Eibach or H&R? 

Caperix
Caperix Reader
3/3/24 6:52 p.m.

I think the fsd has been replaced by special active, not sure if it is a redesign or just a name change.  Fsd's get mixed reviews online, I am thinking of trying them on my 2wd e91 mainly because the sports are a pain to adjust so they end up being set to the middle & left.

rothwem
rothwem Reader
3/4/24 10:35 a.m.

I've had two different AWD E91s.  You'll be fine with 245s, no extra camber required.  I put 245/45/17's on mine with 17x8.5 Et37s.  

As for Bilstein selection, any reason you don't want to go for the B6s?  You'll sit at stock height and it'll handle better.  I got some Dinan camber plates to get some more camber, yes I realize that they put you out of stock class for autox. 

Weirdly, I think the B6 on the AWD cars is better matched than on the RWD cars, I know because I've had them on my AWD wagon and they were awesome, so I put some on the RWD wagon I bought to replace it and they kinda suck--very harsh.  

As far as the B14's go, are you concerned that the spring/coilover adjuster is going to foul on the tire, or are you worried that low=less clearance?  

chknhwk
chknhwk Dork
3/4/24 11:10 a.m.

In reply to rothwem :

GREAT info - thanks for that!

I'm actually looking at 255/40-17's because they're the same size as stock.  The 245/45-17's are a little off and I think the OCD in me would go crazy.  laugh  UNLESS the speedo will actually be more correct with the 245/45's then I might consider them over the 255's (my speedo is always 4mph off at any speed I've checked it at...).

I was looking for a mild drop for aesthetics AND handling improvement - are you saying the car will be able to maintain a better contact patch and be faster on the track with the B6's?  If that's the case I'll have to do some soul-searching...

As far as the B14's go yes, in talking with Apex Wheels they said the B14's might get in the way of 255's up front and may require slightly more negative camber and/or rolling the fenders.  Hence why I'm trying to get more information on BMW-specific setups for this car with a plan of 255's on 17" wheels.

chknhwk
chknhwk Dork
3/5/24 11:41 a.m.
rothwem said:

As for Bilstein selection, any reason you don't want to go for the B6s?  You'll sit at stock height and it'll handle better. 

You can't say something like that and ghost me. laugh

Any other input on Bilsteins or Koni's from the collective (especially for BMW's)?  I thought there'd be more input than this on here...

LanEvo
LanEvo GRM+ Memberand Dork
3/5/24 12:43 p.m.

I had an E90 335xi sedan a few years ago. The stock suspension was horrid; worse ride quality than a Conestoga wagon over a cobblestone road.

Swapped in Koni yellow dampers and H&R springs. Totally transformed the car: better ride quality on the street AND better control in the corners. I took it to VIR once and was very impressed by the handling and balance. 

rothwem
rothwem Reader
3/6/24 10:35 a.m.
chknhwk said:
rothwem said:

As for Bilstein selection, any reason you don't want to go for the B6s?  You'll sit at stock height and it'll handle better. 

You can't say something like that and ghost me. laugh

Any other input on Bilsteins or Koni's from the collective (especially for BMW's)?  I thought there'd be more input than this on here...

Haha hey sorry, I don't visit this forum very often, kinda forgot I posted.  

I guess "better handling" can get pretty scientific.  I liked the slightly firmer ride I got when I put the B6's on my AWD wagon, it felt like there was less body roll and a minimal ride penalty.  

I'm not too sure about the "mild drop" part, the front suspension on the AWD E9x cars doesn't have a whole lot of travel. I would think you'd need a shorter strut body if you're going to go lower and that's not really something I'm very knowledgeable about.  I do know that the B12s are just B8s with Eibach springs, and the body itself is the same length on the B8s vs the B6s, the piston is just shorter so a shorter spring doesn't get loose on the strut at full extension.  The internal bump stop may be shorter though to compensate for the lost travel with the short spring, I don't know for sure though. 

chknhwk
chknhwk Dork
3/6/24 1:15 p.m.

Thanks for the input everybody!  I initially decided on the Bilstein's due to past experience and many people on the E90 forums saying they didn't rust out like the Koni's.  After doing more research I think I may actually go with the Koni Sports - just need to find Eibach springs for my car which I think I remember reading ARE available for my car, I just have to go through Germany for them.  I've heard the H&R's can be a little harsh on the roads.

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