[leopard2lx]

Looking for suggestions on coilovers with good balance between street / track performance and a reasonable price. I want something stiffer and tighter than the crappy stock “sport” suspension but not super harsh for everyday driving.

I know KV coilovers seem to be popular but $1500 + install might be more than I’d like to spend.

[quikM2]

Bilstein B14 / 16's

[phoizgood415]

Im in the market also and I've been doing alot of research and still cant decide. Ive been told the B14s are the best bang for your buck but I've also read that the ride can be pretty harsh/stiff. On the other hand, alot of people seem to vouch for them also.

I heard the KWV1 are more comfortable than the B14s but its about $400 more, I have no problem paying that extra $400 if its noticeably better but I've read somewhere that the rear sits extremely low even at the highest setting, which is the only thing stopping me from pulling the trigger. (I dont know if this was a unique case, if someone with KWV1 can verify)

BC Racing apparently is the same as KWV1 but with galvanized steel body tube versus the stainless steel. I live in CA so I dont know if the stainless steel body is worth the extra $400. Again, since its the same thing as KWV1, I'm worry about the rear height settings.

This is what my finding is so far.

[f32ftw]

I'm also looking for coilovers for my 435 xdrive. I want to retain ride comfort and remove the fender gap. Can anyone weigh in on the ride quality of ST coilovers or BR racing coilovers?

[cfm56d7b]

There is indeed a gap in coilover price / performance between $1K and $1.6K USD.

KW Street Comfort coilovers - at $1.6K - is a very good product offering with the ability to maintain OEM height if required.

[Logicoeur]

Originally Posted by f32ftw

I'm also looking for coilovers for my 435 xdrive. I want to retain ride comfort and remove the fender gap. Can anyone weigh in on the ride quality of ST coilovers or BR racing coilovers?

Originally Posted by phoizgood415

Im in the market also and I've been doing alot of research and still cant decide. Ive been told the B14s are the best bang for your buck but I've also read that the ride can be pretty harsh/stiff. On the other hand, alot of people seem to vouch for them also.

I heard the KWV1 are more comfortable than the B14s but its about $400 more, I have no problem paying that extra $400 if its noticeably better but I've read somewhere that the rear sits extremely low even at the highest setting, which is the only thing stopping me from pulling the trigger. (I dont know if this was a unique case, if someone with KWV1 can verify)

BC Racing apparently is the same as KWV1 but with galvanized steel body tube versus the stainless steel. I live in CA so I dont know if the stainless steel body is worth the extra $400. Again, since its the same thing as KWV1, I'm worry about the rear height settings.

This is what my finding is so far.

Originally Posted by f32ftw

I'm also looking for coilovers for my 435 xdrive. I want to retain ride comfort and remove the fender gap. Can anyone weigh in on the ride quality of ST coilovers or BR racing coilovers?

ST Coilovers are the galvanized version of KW V1, not BC racing coilovers. All three are a good set with ST being the most leaning towards street duty, bc being a good blend, and V1 leaning more towards track.

[phoizgood415]

Originally Posted by Logicoeur

ST Coilovers are the galvanized version of KW V1, not BC racing coilovers. All three are a good set with ST being the most leaning towards street duty, bc being a good blend, and V1 leaning more towards track.

Thanks for the ST correcting. You would recommend BC over Bilsteins?

Do you think ST Coilovers have the same EXACT performance as KW V1 besides aesthetics?

[Logicoeur]

Originally Posted by phoizgood415

Thanks for the ST correcting. You would recommend BC over Bilsteins?

Do you think ST Coilovers have the same EXACT performance as KW V1 besides aesthetics?

The B14 is closer to the V1. Less adjustability than the BCs, but supposedly higher build quality and durability when ran really hard. But I would argue that the replacement parts costs, for the BCs, makes up for this.

The ST and V1 differ only by the branding and external coating.

[reyoasian]

Bilstein B14.
The monotube design is much better than KW V1's, unless you specifically want the comfort of twintube design.

ST are owned by KW however:
1. they are galvanized steel instead of stainless steel
2. they use "imported" inserts instead of wet-filled shock bodies
But they really do bring in more value

BCR are stance coils, not for performance.

Originally Posted by phoizgood415

Thanks for the ST correcting. You would recommend BC over Bilsteins?

Do you think ST Coilovers have the same EXACT performance as KW V1 besides aesthetics?

Bilstein > BCR.
ST vs KW, read my post above.

[leopard2lx]

Originally Posted by reyoasian

Bilstein B14.
The monotube design is much better than KW V1's, unless you specifically want the comfort of twintube design.

ST are owned by KW however:
1. they are galvanized steel instead of stainless steel
2. they use "imported" inserts instead of wet-filled shock bodies
But they really do bring in more value

BCR are stance coils, not for performance.



Bilstein > BCR.
ST vs KW, read my post above.

I was reading that with Bilstein B14 you can only adjust ride height. Do you know if this is correct and can this be easily adjusted by the driver or do you need a shop to do it? I also assume you cannot adjust how “soft” or “harsh” the ride it. There only the default setting.

[Alpine-F80]

Originally Posted by leopard2lx

I was reading that with Bilstein B14 you can only adjust ride height. Do you know if this is correct and can this be easily adjusted by the driver or do you need a shop to do it? I also assume you cannot adjust how "soft" or "harsh" the ride it. There only the default setting.

This is correct, B14 only allows height adjustment, and the ride will be quite stiff if you're driving over imperfections on the street but are arguably the best handling of v1, BC, etc. — everything is a trade off at this price point.

I personally don't have any serious plans for tracking and use the car as a daily so I went with BC BR (used for good value). What you need to do is find out what you're truly trying to get out of your suspension and that will really help narrow down your options.

Cliff's notes:

- B14 - great performance, rough ride on street, no dampening control
- KW v1 - solid performance, good ride on street but still firm, no dampening control
- ST - same as v1 but not stainless so avoid if you get snow/ice where you live
- BC, d2, etc - average at best performance, can be a smooth ride or super jarring ride depending on dampening setting, parts won't last as long as kw/bilstein but are super cheap and easy to replace

[_tlink]

From personal experience with BC Racing BR series they are stiff but not in a bad way. You buy these knowing they are going to be a little harsh on bumps, but the stiffness gives a lot of confidence when driving. It's not to tracking standards, but for the price and convince being able to adjust for ride height the price tag can't be beat if you are only using on the street. I paid 995 for springs, 400 for install, and 120 on alignment, so a grand total of 1515. Still enjoying them

[exE36M3]

Silly idea... how about something like HR or Eibach sport springs and Koni SA shocks?
It's not like you guys are adjusting every weekend for track conditions right? With the Koni, you can adjust the shock for softer or stiffer.

Set on Tirerack is about $800. Springs run $199-$350 whichever you prefer.

[Logicoeur]

Originally Posted by percychow

Silly idea... how about something like HR or Eibach sport springs and Koni SA shocks?
It's not like you guys are adjusting every weekend for track conditions right? With the Koni, you can adjust the shock for softer or stiffer.

Set on Tirerack is about $800. Springs run $199-$350 whichever you prefer.

Springs and shocks are a hit and miss. The shocks arent valved specifically for the springs people pair them with so it will never be as symbiotic as a coilover. I wouldn't go less than the BCs. Just because the height and dampening is included, and you dont intend or expect to use them doesn't mean you should look at products without those, imo. At least they are there if things ever change.

[valve float]

love my B14's...keep eye open for ecs scratch n dent sale...got 'em for ~$750usd...

[Alpine-F80]

Originally Posted by percychow

Silly idea... how about something like HR or Eibach sport springs and Koni SA shocks?
It's not like you guys are adjusting every weekend for track conditions right? With the Koni, you can adjust the shock for softer or stiffer.

Set on Tirerack is about $800. Springs run $199-$350 whichever you prefer.

Actually this is a great point, while I didn't go this route because I wanted the ride height control a coilover offers, for those looking to upgrade solely for performance gains, while also closing some of the wheel gap, a spring and shock combo will offer the best performance without completely sacrificing ride quality at the lowest price. As Logicoeur said though, it can't just be any spring + shock, they will need to be paired correctly.

[leopard2lx]

Originally Posted by valve float

love my B14's...keep eye open for ecs scratch n dent sale...got 'em for ~$750usd...

Is that ECS Tuning you are referring to? If so, I’ve already bookmarked their page (as well as a couple of other companies) and keeping an eye out for sale

[52172]

Fortune auto 500 coilovers are 1475 and pretty nice plus they come with camber plates in the front I think I'm going this route.

[scostu]

https://f30.bimmerpost.com/forums/sh....php?t=1501682

[scostu]

per johnung......….


"I'm glad that you found the information helpful. I gotta meet that FaRKle! guy someday! I've been driving the Eibach springs/Koni Active dampers combo for about 9 months now. They have exceeded my expectations. I wanted to tighten up the suspension without adding more harshness.

This is long winded but I thought it might help to give some insight into my thought process along the way. Everyone has their own priorities when it comes to modifying their car and that gets them to different solutions. That's why this car stuff is so much fun!

The Suspension Goals:
I've done mods in the past with other cars. Adding sport suspension components usually involves that type of trade-off. Great handling cars usually don't handle bad roads too well. This is a family daily driver. I wanted a car that is both comfortable on family trips and really fun when I'm driving by myself, hitting that curve in the road.

Picking the right sports sedan!
My wife and I went through a process in looking for right used car for us. (First fun car after decades of many kids, minivans and big SUVs.) She had already driven a Lexus for years with a comfortable highway ride that had nothing in the corners. Mercedes had some attraction because they take that smoothness in a much more German car direction. IMO Mercedes approach still isn't the right mix for a sports sedan. The stock 335i x-drive was much closer to the ultimate (driving machine! Had to say it!) It was actually my wife's eyes that lit up when she drove the 335ix. I never thought that she'd go that sporty so I didn't think to suggest. I was pleasantly wrong!

How the 335ix suspension might be improved to fit our needs
After driving our "new" used car for a few months I got a sense for the drawbacks of the stock suspension. The difficulty was that the issues are on opposite ends of the spectrum. We live in the Northeast. The stock suspension had a teeth rattling aspect to it when you hit rough roads and potholes. Got the car in December and set a goal of modifying the suspension before leaving in July on a 3,000 mile road trip with my son to visit a dozen potential colleges. I was afraid of losing my mind on a long trip because of how poorly the stock suspension handled road seams....endless jarring bump...bump...bump.

On the other side of things, that harshness wasn't even a compromise that had resulted in great handling. Even with xDrive, the suspension of the stock car just didn't handle curves well. The car understeered with a lot of body roll. Bottom line: It could be so much better, so much more fun!

Initial Assumptions
When I began my search, I honestly expected to discover that the compromise that I hoped for didn't exist. I thought that I would have to follow the typical scenarios to get better handling, most of which in my past experience take away, at least a bit, from the ride comfort. Early on I would have bet that my final solution would have been dampers from say Bilstein or Koni, at the milder end of their sport shocks, i.e. Koni adjustable yellows. A mild drop spring set like the Dinan at 0.75" was a good possibility too. I spent a lot of time investigating coilovers but costly and lots of divergent opinions. Very much a more sporty direction than our goals and could spend that money better on other priorities.

New Damper Technology
In researching the Bilstein and Koni products I spotted the Koni FSD technology. I took it with a grain of salt. I've spent most of my career in a technical industry at the forefront of technology. There was a lot of sorting through marketing materials to figure out what was a real breakthrough that could actually be implemented and the other 80% that was mostly marketing B.S. Koni developed this technology with McLaren and the science seemed sound. The more I researched, the more solid it appeared to be. I read many actual user comments from Europe because Koni hadn't really been marketing the technology at that point to end users in the U.S.

Eibach's Great Reputation
What clinched it for me were many conversations and emails that I had with the top Koni technical guy who was very credible and answered every question that I had over a couple of months. That's how I learned about Koni North America having actually tested their xDrive Special Active dampers with the Eibach spring set. I did research on Eibach at that point too and learned how solid they are.

Use Stock Bump Stops in this Configuration
Koni's technical guy is also the person that insisted that no bump stop changes were necessary. That was based on actual testing with a shock that hadn't been released yet so I took his opinion over a Dinan sales guy that was trying to sell bump stops for a shock that he had never seen or sold. (It's another long story but the first set of the Koni Special Actives on a 335ix customer car in the US went on my car.) So my suspension was installed with unmodified stock bump stops. Based on my driving experience, Koni was correct about the stock bump stops being fine in this combination.

Other Suspension Mods: Sway Bars
A suspension is the sum of its many parts working together. I've already posted about my belief in sway bars to combat body roll in corners. Labor is expensive to install sway bars on the F30 but the H&R sway bar upgrades on my car make it corner flat!

Don't Forget a Key Component: Tires!
Another key component of the suspension are the tires. Big thanks to alohasurftoad and his great advice on wheels and tires. BMW gave me my first experience with runflats. For over a year I was steadfast in wanting to stay with runflats and just upgrade to the best one that I could find. A month ago I changed my mind and am so glad that I did. (I made separate posts about the kit that I now carry in my car in case of a flat.) I decided to save the tread on my existing runflats to use next winter.

With our Hawaiian guru's help I made two tire changes:

1) Upgraded from runflat tires to the best possible summer tire, the Michelin Pilot Sport 4S.
2) Upgraded from the stock square 225/45-18 size, to the wider and better handling 245/40-18.

This tire upgrade was as dramatic of a suspension change as my shock/springs/sways upgrade. The new tires make it seem like the previous runflat tires were wooden wagon wheels. The car now sticks to a curve like glue. The other day I drove it on I-95 and some horrible roads in the middle of Philadelphia. The suspension has evolved tremendously. It now handles rough roads and road seams like a luxury Lexus and handles high speed on-ramps and off-ramps like an open wheeled race car. The Michelin PS4S has an outside tread that you can actually feel grip the asphalt as soon as you turn the wheel into a curve. Just amazing!

The last piece to my suspension mods will return from powder coating next week for installation. It's a front shock tower brace. I'll post about that later.

I've written a book, or at least a short story, as usual. Hope this is all helpful to someone, down the road! Fun With Cars!"

[leopard2lx]

Originally Posted by Alpine_F30

This is correct, B14 only allows height adjustment, and the ride will be quite stiff if you're driving over imperfections on the street but are arguably the best handling of v1, BC, etc. — everything is a trade off at this price point.

I personally don't have any serious plans for tracking and use the car as a daily so I went with BC BR (used for good value). What you need to do is find out what you're truly trying to get out of your suspension and that will really help narrow down your options.

Cliff's notes:

- B14 - great performance, rough ride on street, no dampening control
- KW v1 - solid performance, good ride on street but still firm, no dampening control
- ST - same as v1 but not stainless so avoid if you get snow/ice where you live
- BC, d2, etc - average at best performance, can be a smooth ride or super jarring ride depending on dampening setting, parts won't last as long as kw/bilstein but are super cheap and easy to replace

Is it easy to adjust damping and height on the BC coilovers? I would probably have it stiffer as I hate body roll and any kind of floatiness.

[52172]

Don’t leave fortune auto out of the picture. 1375 for a fully adjustable set with camber plates.