KONI FSD + EIBACH PRO-KIT MAZDA3

Side By Side, Mazda3 OEM front strut vs Koni FSD.

This will be my first NEGATIVE review of a product.  I contacted Koni with my concerns and got some lame computer auto response with a warranty link to a PDF.  meh...

I paid $793.21 shipped from suspensiononline which is an online reseller run by paragon products.  Product was shipped directly from Koni-NA, and took 8 business days to be at my door.  I didn't get a tracking number until business day #8, but at least I got one.

Koni FSDs are stamped that say they're MADE IN HOLLAND!  Isn't that VEIRD?  hehe

I've already installed the Eibach camber kit and will be upgrading my suspension from S-techs/OEM struts which have worn down in about 10k miles of rough freeways.  Basically, I push the compress the OEM strut all the way, it sinks with little resistance, and then takes FOREVER to come back out and extend with a terrible sound to them like a "bubbles and oil" sound.

I feel as though the ride has gotten considerably rough/bumpy from my S-techs and was either going to go with coilovers or this Koni/fsd combo.  Supposedly the Gallardo has FSDs which is pretty sweet.  I also commute 50 miles on the weekends with sometimes kids and nobody seems to really like the ride comfort on my S-techs with worn down shocks.

The prokit drop looks even and OEM.  The S-techs have a severe drop in the front.  I notice that driving I feel a bit higher on the new setup.

The ride was greatly improved due to it being compared to worn out struts + s-techs.  Bumps are excellent, though I'd have to say that the stock suspension is probably more comfortable for certain mid size bumps.  The FSDs soak up small bumps really well as well as the dots for median lines on the freeway.

The suspension feels like it can absorb small bumps, but then when there's a huge weight transfer from either a large dip or sweeping curve, there's much less body roll than OEM and definitely less roll than with the S-tech + OEM strut.  Basically, if you are driving and hit a long dip, you will first feel a small drop from stage 1 of the shock, but then stage 2 of the shock kicks in and stops the car from moving any further.  To describe it, I'd have to say it's soft for minor road imperfections, but stiff for everything else.  Compare this to Koni Yellows or an STI suspension and I have to say that an STI will feel more stiff overall.  It just won't have the high frequency damping capability the FSDs have.

It actually feels pretty solid how it reduces body roll which adds a lot of confidence.  I'd much rather have the feeling of reduced roll from stiffer suspension than just adding a sway bar.

One CON is that since it soaks up a lot of the initial impact of bumps, there's a somewhat isolated feel now compared to what I had before.  Before I could pretty much feel every little pebble on the road which was crisp and distinct.  Now those pebbles disappear and I feel a little like I'm floating, except without the body roll associated with a "floating" ride quality.  My 89 Buick Electra comes to mind...  The ride was super smooth, but the car felt like a boat.

The suspension got quieter, perhaps due to the slight change in suspension alignment.  I did not notice my camber to be visibly out of whack, but I'm due for a four wheel alignment in like a month in case the springs sag slightly.

One problem I have with the FSDs is actually the craftsmanship.  It appears that when I compared the two front shocks, one of the brackets was a little less than 1/8" lower on the right side, than should be.  The result was a slightly different mounting position in the spindle which probably doesn't affect the ride, but it bothered me nonetheless.  I suppose I could show pictures and bring this up directly with Koni and explain it to them that the shocks don't fit the same left/right, but it's a lot of work taking them out and I don't think it'll be worth the trouble since it's probably moot.  This leads me to believe that the brackets are welded by hand and imperfections are highly possible.

During Install, I used quarters and put the bolt in backwards to separate the "C" clamp to free the spindle.  This left me with only 10 moderate hits or so to loosen it.

I didn't like aligning the rear arms with the wheel housing though.  That was probably the hardest part for me.  I had a wide variety of snap-on tools and tightening the nut on the rear koni struts may require a unique deep reaching open ended socket wrench.  You also need a special socket or some type of locking pliers to hold the threaded shock in place while you torque the nuts down.

The spring compressing is by far the best part if you have a good spring compressor.



Take note, that to remove the rear struts, you just remove the two bolts from inside the wheel well, and the lower strut bolt.  A breaker bar definitely comes in handy.  I used a powered driver to help remove certain bolts quickly.

I calculated the installation of Springs and Struts to take 6 hours at most.  I started at midnight, and finished cleaning up by 6am.

Update 2-27-07

After 2 months of daily driving and about 2000+ miles.  The Shocks have broken in, and the springs have settled.

I must say that the suspension is noticeably more rough than before, but it still absorbs bumps effectively.  I just notice that I feel the bumps a lot more than I did before.

I'd have to say that the OEM suspension has a more comfortable "floating" ride quality than my broken in FSD/Prokits.

So this mod should be for somebody that wants a suspension upgrade to improve handling, but not necessarily comfort.

I do however think that the ride quality is not as rough as most other shock options.  For the most part, it feels good.

I'll keep this thread updated if I notice any furthur changes in the suspension behavior.

Update 8-6-07

Sadly, after approximately 15,000 miles of 70% freeway and 30% highway.  My FSDs are now considerably more rough and bouncy than before.  Bumps that were not too bad have gotten more harsh, and the shocks don't soak up the small bumps as well.  It is beginning to feel similar to my S-techs on worn OEM shocks...  it sucks.

I was honestly hopping to reach about 50,000 miles until it got this bad, and i'm a bit disappointed that I only got 15,000 miles.  Though I guess it was because of the lowering springs, rough freeways, and aggressive driving.

So DO NOT buy the combo unless you want a rough ride in about 15,000 miles.  I'd suggest FSDs plus OEM springs now.  Or just to avoid FSDs all together.  They were awsome up until 10,000 miles, then I think at the 14,000 mile mark I began to notice the bumps getting worse and worse.

The car still handles great and is firm, it's just got rough and gets annoying for daily driving.

Update 9-27-07

I tried to contact Koni, but their email contact for north america no longer exists.  I decided to give up and accept my more "bumpy" ride.  heh

On a good note, the ride has not noticeable got any more worse in the month and a half from my last complaint.  So I'm grateful that the low frequency damping is still good and firm.  The ride is still more harsh than when it was new, and I have no confidence going over speed bumps and cross gutters.  However, I drove in an STI, and also a regular WRX, and the suspension just feels more firm.  I think I have a marginal degree of bounce and I notice it when I hit a sharp bump at high speeds.  It's like a resonating short bounce.  I do think that I have less body roll than the WRX, but the feeling of the road seems to be a little "disconnected" now with my FSD/Prokit setup.  It's a little difficult to explain, I just know that the feedback from the STI suspension is 100% superior.  I like it how I can feel the sharpness of the bumps in the STI, while in my car it feels like the tire deflects off the bump and bobbles up and down a bit there-after.

This may 100% be the Kumho KH11 tires, but when I'm taking a high speed turn, the car feels more squirrely and jittery.  It does not feel planted and smooth...  This is one concern I have and I can't really make a statement on what exactly is to blame.

I would need to try Koni Yellows and then maybe OEM shocks on my car to really know what my FSDs are doing to my ride.

Update 5-15-08

FSD's are CRAPPED OUT.  My ride quality has gone down the hole.  it's been 8 months since my last update and now for sure my shocks feel like they're worn out.  I take a turn fast, the car leans more than it used to.  I hit a medium sized pothole or dip and my car SLAMS into it and it feels like somebody just hit my car with a sledge hammer.  (No damping whatsoever)  Even smaller bumps and uneven slats hit my car hard that it shakes the whole cabin.  I no longer have excessive confidence in my cornering abilities I think my tires are the only thing giving me grip in turns.

The car goes over a decent dip and I can feel the shocks hit the bump-stops.  I find that the car hits the bump stops WAY more than before, now that I think about, I don't recall ever feeling that "bump stop" collision when my shocks were new.  When my passengers start making comments when I go over train tracks or uneven slats is the time I know my suspension is worn.

I firmly do not suggest the FSD to anyone unless they are getting it as a short term investment and don't plan on having their car longer than 25k miles...  Cause that's how long it'll take for your shocks to wear into something mediocre.

I am now shopping for new shocks and my FSDs will go into the trash because I wouldn't resell them for $10.