Talk to me about Koni dampers

The Bilsteins in my 128i are looking a bit the worse for wear. Talking to my BMW indy a few weeks ago he said that newer Bilsteins seem to be having significant problems with QC, which made me start thinking about alternatives rather than simply trying to warranty and replace the Bilsteins. Having to warranty the fronts in my E39 after only a few years certainly adds to the concern about long-term viability. They are also a little on the harsh side in this application.

This got me considering Koni. There are three options available, in descending order of cost: Sport, Special Active, and STR-T. I want the car to handle well, but it is ultimately a street car used as primary transportation. I know some are adjustable, but I really don't see myself tweaking whatever is eventually installed beyond the initial setup, so it's not really that much of a bonus here. Suspension is Eibach springs and M3/1M control arms, but otherwise stock. I know very little about the Koni line, as I have always used Bilsteins. Please enlighten me as to what I want.

I use Koni's whenever I can.  Currently on the RAV4 and Locost.  Their top of the line stuff is very good.  If you have the funds to spend on them, I'd get that.  Hey, twelve bills coming soon... I haven't tried the STR-T line. 

Best thing to do, though, is call up the Koni America tech support and ask them your questions directly. 

The strt is the go to for a daily/autocross setup on the nc Miata. 

I love the koni yellows in a performance application. 

Ive driven the strt on a c6 vette. Fantastic dampers gor a street car in that application. 

I'll also toss in a mention for the AGX for a daily 

If you don't need adjustability I'd recommend the "Special Active".   You can call to check, but I believe that's a new name for what they were calling FSD (Frequency Sensitive Damping) a few years ago.  We had a set on an E46 330CI and were very please with them.  They give a generally firm ride on smooth surfaces but use a "blow-off" technology to relieve pressure when hitting expansion joints and big bumps.  I live in the flatlands of SE Georgia, but I bought them on the recommendation of someone running them around Boston roads, and I was happy with them.

I have used bilsteins and teins always. 
 

first time went Koni yellow on my 01 GSR. Been pleased with them. 

Love the Koni yellows, have also loved Tokico blues on street cars.

ChrisLS8 said:

I'll also toss in a mention for the AGX for a daily 

I'm sure it's not the same for every damper they make, but my agx's were super stiff in the rear and soft in the back and never changed, no matter what I turned the clicker to. 

Of the Koni options, the Special Active is what you would probably want for your use. The frequency response tech is a little old at this point but plenty of OEMs still use it and the Koni system is one of the better ones. I don't have any direct experience with the Special Active line or any knowledge of recent Bilstein issues, but Koni products in general aren't exactly known for amazing quality control either. Not that I would shy away from them, just putting that out there as something to consider. They are usually pretty good about warrantying stuff though.

I've owned one pair of Koni STR-T shocks meant for a Jetta that I put on the back of my Suzuki SX4 and they squeaked out of the box and never got better.  Really noisy and annoying.  Replaced with Monroes and those have been fine.  So, uh, do with that what you will.  Also the body of the STR-T's surface rusted fast.  Not impressed.

The OEM ones are great as are the str-t

Str.t is a yellow set to full soft. Same lifetime warranty, but they're made in a different factory (I forget where, Vietnam maybe?) and they do have a higher warranty claim rate. It's a stock replacement, that's about it. 

Special Active is a blowoff valve setup. It has a weak point in that it tends to hit the bumpstops hard if you're at all limited on travel. I did some comparison driving in a Mustang at the SEMA show and we did get into the stops hard a couple of times. Felt good overall, I'd use them for a car like the Tesla. Just be aware.
 

For a car on Eibach springs, I'd want Sports. I assume they are lowering springs with a mild increase in rate, which means they're already into bumpstop territory. 
 

Id take any of them over Bilsteins. I've never liked Bilstein's tuning, they have a characteristic "jiggle" to the ride that doesn't seem to come with any benefit. I have Koni Sports on my E39. And my Vanagon. And the back of my CRX. And one of my Miatas. And Bilsteins on the WJ, which jiggles. 

In reply to 02Pilot :

I have no experience with BMW's but my Koni's on the Black Jack special worked perfectly during decades of Vintage racing and are still on it in the museum it's in now. 
The aluminum Koni's I used on the V12 E type   Roadster I built for Vintage racing I lost track of. So I can't comment except to say they sure looked good.  

I'm a Koni guy as well, I think they do a good job without destroying the ride. Note most of my Koni experience has been with track / race cars but I have had them on a couple of street cars.

dps214 said:

Of the Koni options, the Special Active is what you would probably want for your use. The frequency response tech is a little old at this point but plenty of OEMs still use it and the Koni system is one of the better ones. I don't have any direct experience with the Special Active line or any knowledge of recent Bilstein issues, but Koni products in general aren't exactly known for amazing quality control either. Not that I would shy away from them, just putting that out there as something to consider. They are usually pretty good about warrantying stuff though.

In fairness, I've bought 2 sets of Koni's and they both rode great, but both started out bumpy..., The first set were KoniSports for a Ford Focus.  As soon as I got the "out for delivery" email I jacked it up and started taking things apart.  When they got there I put the rears on first, the the front left strut.  The only problem is that when I opened the box for the front right strut it had another front left strut in it..., They were very responsive to my problem, but the car did sit on jack stands for 2 days before I got to take it for a test drive.  Wife and I did 1-2 autocrosses a month for 5 years and put a 197k miles on the car and they were still holding up well.  

The second set were the FSD's for her 330Ci.  I opened the box and found 3 the same length and 1 that was shorter.  I called them up and heard something about a missing internal bump stop.  Again, they sent the replacement overnight and the shocks were still working great when I sold the car with 238k miles on it (135k on the FSD's)  

I'm thinking since it's a Dutch company, maybe they take liquid lunches (or smoke breaks....)

Yeah I guess I should have been clearer...initial quality is the issue. Basically as far as I can tell either they're bad out of the box or good forever. I've seen at least one that was bad out of the box, another one that went bad after one season of autocross (I suspect it was bad out of the box but no way to tell after the fact). I've also seen multiple 30+ year old koni sports that were fully functional.

Also Keith is right, I glossed over the eibach springs part, sports are probably actually the correct choice in this case.

I think the special active would be your best bet. They used to specifically pair the fsd (old special active) with eibachs. I have dad's on my 996 and also had some on my e46 touring. I've had  lots of yellows on various cars and they are good, but they won't be as comfy during the daily driving part of your use. 

Well, that's clear as mud - thanks!

The Sports are the obvious answer except that they're twice the price of the STR-T. The Special Active is intriguing (the roads here vary between not good and downrange at the Afghan mortar training area), but the big question is how they work with the Eibachs on this platform. Koni sells kits with the Sports and the STR-Ts plus Eibach springs, so I take that as an endorsement of compatibility. They also suggest that such kits exist with the Special Actives, but they don't list one for my car. I suppose I'll have to check with them to see if that combo will work, or if it will just be on the bump stops all the time.

Keep those opinions coming. Especially interested in hearing more about the Special Actives and STR-Ts, which seem underrepresented so far (not that this surprises me).

It's going to come down to your tolerance for the trade of between price and performance. Do you know how the eibach springs compare to stock in rate? Personally I wouldn't put str.ts on anything but stock springs, especially if the roads are as bad as you describe.

I don't know the spring rates of the stock (M-Sport package) stuff and the Eibachs, but there's definitely a significant increase.

back in the dark ages , "BI" before internet , you could send your old Orange Konis in and have them rebuilt , 

Is that still done ?

Yes. 

02Pilot said:

Well, that's clear as mud - thanks!

The Sports are the obvious answer except that they're twice the price of the STR-T. The Special Active is intriguing (the roads here vary between not good and downrange at the Afghan mortar training area), but the big question is how they work with the Eibachs on this platform. Koni sells kits with the Sports and the STR-Ts plus Eibach springs, so I take that as an endorsement of compatibility. They also suggest that such kits exist with the Special Actives, but they don't list one for my car. I suppose I'll have to check with them to see if that combo will work, or if it will just be on the bump stops all the time.

Keep those opinions coming. Especially interested in hearing more about the Special Actives and STR-Ts, which seem underrepresented so far (not that this surprises me).

You'll only spend the money once, but you'll have the shocks on the car for years. Cheaping out on suspension can ruin a car. Just get the Sports. They're more likely to have the correct valving and they're more reliable than the Str.T. 
 

Koni sells the Eibach/Str.T combo because it's a price leader, not because it necessarily works well. 

californiamilleghia said:

back in the dark ages , "BI" before internet , you could send your old Orange Konis in and have them rebuilt , 

Is that still done ?

Yes but nobody in the US has the ability to gas charge them. And iirc there's only two third party shops left that do it, koni stopped doing in house service somewhat recently.