Well Koni didn't come through with Dyno results. They did send the following. No clue what it means though..

Monty,
Thank you for contacting us here at KONI NA. Unfortunately, I do not have Force v. Velocity graphs readily available for each of the dampers offered. I can however provide the factory specs at which the shock are tested to for quality control.

Tested at .33m/sec (13in/sec)

Front FSD- 8745 1328
Compression – 350N
Rebound – 1350N

Rear FSD – 8745 1329
Compression – 900N
Rebound – 1650N

Sports
Front – 8741 1573sport
Compression – 500N
Rebound – 1250N

Rear – 8740 1574sport
Compression – 1050N
Rebound – 1550N




Mason O’Hara
Technical Sales Represenative
KONI - an ITT company

1961A International Way Hebron, KY 41048
(859) 586-4100, (859) 488-0324 mason.ohara@itt.com
KONI NA | Home www.koniracing.com www.konirv.com

These specs don't show how digressive the shocks are, but basically what I'm getting is that the Koni FSDs are lighter in compression (especially at front) and firmer in rebound than the sports are when set at full soft setting (which is where Koni measures their specs, as I understand it). If the sports were adjusted firmer, I expect their rebound rate would first match, and then exceed, the FSD's rebound damping.

The specs Koni provided for the rear sports match the dyno plots I posted for mine - look at the far right end of the graph (highest speed measured is where Koni checks their specs, apparently).

And that all makes sense. Since this test is at the high frequency 13ft/sec, this is where the valve on the FSD is wide open and providing the least resistance. This is what would be happening over say a speed bump. This allows the spring to compress while transferring the least amount of upward force/lift to the chassis. The info that is missing is what is the force at the low frequency setting? I think I read somewhere the FSD is actually stiffer than the Sport (full soft) in the low frequency travel.

Hi guys - new member.
I have just bought a bargain 123k mile 2002 2.7, looked after but obviously a little past its best. I am researching options for dampers.

I've had a quote for M030 at about £1100, I can get Koni sport or Koni FSD for about £550.

Currently I am not fussed about lowering the car - so replacing the shocks only could work. I would probably want to add in some Anti roll bars though.

Has anyone run the Koni sports (or FSD's) on standard springs, particularly older ones? Reccomended or not?

My thinking is a decent ride height and soft-ish springs, but with stiffer ARB's will give a good balance for driving on the tight bumpy roads we have here in the UK but not too roly-poly on the odd trackday.

Why not just buy Koni's package? Sports Dampners and Ebach springs?

I have seen some talk about this package but hadn't seen one for the 986 Boxsters, do you have a link? Would be a neat package.

I'm gonna leave your handle alone......:cool: As far as the Koni FSD's go they are designed specifically to use the stock springs on your car. They do have a set that comes with springs if desired.

Steved0x,
Just call them in Hebron, Ky. I was there for a tech session last week. Great Guys and real helpful.
859-586-4100

ditto the above - I've not seen a Koni supplied spring/damper package available (certainly not in the UK at least).

Ref the handle - don't ask!

I wasn't able to get anyone on the phone (it directed me to leave a message and then said the mailbox was full and hung up on me, I was trying the tech line, maybe should have tried sales :) ) But I emailed them and they got back immediately.

Koni confirmed that the FSD works with 986 Boxster springs, either M030 sport or "regular" (did not ask about ROW springs but they are popular in the UK so I imagine yes). It is compatible with the Eibach Pro kit springs for Boxster, which Eibach doesn't make anymore, so there is no kit from Koni for Boxster that includes springs. Eibach does still appear to make the Pro-kit springs for 996 2WD variants, and I think that is what Koni offers with their FSD+Springs kit for 996. They are listed as lowering the car 1" front and rear.

From time to time a set of the 986 Eibach pro-kit comes available for sale - there was one on here a while back, new in-box.

I have H&R springs on mine. Lowers about 1"

Seeing as this thread comes up top of Google when you search for "Boxster Koni FSD", I thought I'd add that in the end I went ahead and ordered them, in the post currently. I'llet you know how I get on once they are fitted.

Too funny! I pulled this up yesterday thinking about closing or at least adding to the thread I started, but felt I wanted a little more time to evaluate. I installed these FSDs ~1k ago. I just had the alignment done. Unfortunately a comparison to the stock system is limited due to my stock driver side shock was shot. Good news is all other suspension components were in good shape so no major changes there. What I can say is I am extremely happy with them. Broken pavement no longer jars the suspension, bumps and potholes are now soaked up and have a soft and "plush" feel. Turn entry is immediate and much firmer with hardly almost no body roll. Uneven pavement in the corner no longer unsettles the car, the failed front shock could have contributed to this though. Bottom line is if you're a dedicated racer and have to have your ski boots buckled so tight they hurt, then these are not for you. However if you want increased comfort and are tired of gritting your teeth when driving onto a bridge but don't want to give up any handling, then I wholeheartedly recommend these shocks. I am impressed so far.

edit: I have a close friend that has a 2001 S with 107k that is meticulous with maint. He has the Bilstein sports w/ HR springs. I have driven tis car multiple times. My feeling is the FSDs give up very little if any to the Sports handling wise but I feel are actually superior to the Sports on turn entry. Remember this is the low speed circuit where the FSDs have the firmer valving.

Details are: 98 base w/M030 sways front and rear. Michelin Pilot SS. Alignment specs: Front- Camber 0.3 deg, Caster 7.7, Toe 0.03 in. Rear- Camber -1.7 Toe 0.10 in

I put a set on my wife's 06 bmw wagon grocery getter. After a year and a half, one of the rears started pissing out fluid. Switched to Bilsteins and no problems after 3 years. YMMV

That's very reassuring to hear! I also have all new coffin arms, tuning forks, top mounts etc to go on at the same time so I'm expecting a dramatic change - it's currently feeling very worn out!

..........

I had replaced my rear upper control arms (tuning forks) several thousand miles ago, I did replace new Bump stops, bearing plates and boots. My lower control arms were good. To do the fronts I only removed the calipers, rotors and top strut mount. Rears I disconnected the control arms at the camber and toe adjustment points. As an FYI the paint on the strut body was so thick on the rear they would not slide into the hub carrier. On reassembly I loosely assembled the control arms then carefully jacked the hub carrier up onto the strut.
Will be interesting to hear your thoughts! Gives us older car owners the ability to have a similar effect to the expensive PASM on the later cars. I really like mine. Now if StevedOX would weigh in with the track perspective......:D

Seems QC and handling is a lost art nowadays. Hopefully I'll get better results on my Porsche golf cart. I opened a case with my FSDs when they arrived when the shaft was stuck completely through the original box! Somewhere between the Koni factory and the sellers warehouse they received some really special handling. The struts were well packed with expandable foam so it took a real blow to cause that damage. Of course I've watched my skis being tossed 15 feet at the airport, and that was right in front of me! So nothing surprises me any more. I did a very careful inspection with magnification, especially the shaft but found only a minor paint scratch, no dent, on the body of 1 where a spring perch made contact and rubbed. Based on the struts positions in the box I don't believe any contact was made to the polished surfaces but the seller agreed to cover if they fail.

Oh and when I put the Bilsteins on my BMW one had completely lost it's N2 charge right out of the box so seems no one is immune.

I have the bilstein shocks also and I must say that they are stiff but not uncomfortable. Handling is good on rough roads and ride is more controlled.

I feel like I have replied to this thread and my replies aren't showing up, so this post is a test. Yes I love them! Search for posts by me with the word "koni" in them to see my various thoughts, or maybe my posts to this thread will show up...