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Premium Member
2,999 Posts
Discussion Starter #1 (Edited)
By now, Im pretty sure most have known about my searches for performance parts for my car. One of the things that eluded me was a reasonably affordable, high performance strut.

I had used 2nd gen Illuminas but those were limited for my needs(but useful for the large majority of people). I looked for more. I had known about a Koni application for the 1st gen(specials), but it would need to be worked upgraded for my usage. Another possibility was the European Koni Sports for the 2nd gen. But without knowledge of what the differences were I chose to not have it imported on the chance it may not fit.

This all ended when Dutch626 located a set of NOS 1st gen Koni Sport inserts in the Netherlands. Further down the road I found information which lead me to believe the Euro 2nd gens would have fit the 1st gen. It took a bit of luck and being in the right place when Tri-point Engineering offered me a set at a discounted price.

While the 1st gen Sports may forever be gone, the 2nd gen Euro Sports and the 1st gen Specials are still very much available.

This then will be the How to for those who choose to use the 2nd gen European Koni adjustables for the 1st gen.

Lets go.

Premium Member
2,999 Posts
Discussion Starter #2 (Edited)
Now, youll need a few items to get this all done..

-purchace Koni inserts
- Factory service manual
-Spring compressor(these can be rented at most auto stores)
-A jack and jack stands(a lift would be ideal)
-Assorted hand tools(ratchects, breaker bars, sockets, etc.)
-Air tools(this is a maybe, but it makes life a lot easier)
-dremell, grinders, cutoff wheels
-pipe cutter, hacksaw
-drill, metal cutting drill bits

Ration out some time to do this project. A weekend will be more than enough, but a bit of prep time will be necessary leading up the installation.

Hey…while you are down there, how are your control arms doing? Boots in good shape? What about the steering tie rods? Might as well make a project of it.

There are 3 possible Koni inserts to be used in this project. For the most part the installation process will be the same.

Koni Specials (reds)

Part numbers: 86-2413(front), 86-2414(rear)

These are readily available and will cost about $130-140. They are internally adjustable for rebound only ( and less aggressively valved than the “sport”(yellows).

Koni Sport (yellows)

(A)The 1st gen application is no longer made, but if any still exist and you are lucky to find a set (Good luck on this as I may have the last of the NOS inserts).
Part number: 8641-1183 (front), 8641-1184(rear)

(B)The next best thing(and more available) is the European 2nd gen application
Part number: 8610-1305(front), 8610-1306(rear)

They will be @ $160-170 (minus importing)and can be imported through places like

They are externally (rebound only) adjustable. They are also 2” shorter in front and 1” shorter in the rear compared to the stock struts. Because of this some adjustments will have to be made to have them fit acceptably. These will be the items we will be focusing on in this install.

All koni shocks are rebuildable, revalvable and upgradable(IE custom revalves, strut shortening, conversion of internal to external adjustment…for a price of course)

Finally, Koni has a lifetime warrantee on their products against defects and workmanship if the car is street legal and the shock is the correct application. For us this means the specials are covered but not the imported 2nd gen sport inserts(Koni will work on the shocks, but they wont be fully covered as they were not a US application)

And here are the differences in measurements for the two types of Konis.

................. 1st gen 2nd gen
shaft length: 18.3cm 15.9cm
shaft diameter: 22mm 22mm
body length: 31.7cm 29.1cm
body diameter: 44mm 45mm

shaft length: 20.8cm 18.2cm
shaft diameter: 22mm 22mm
body length: 37.6cm 36.3cm
body diameter: 44mm 45mm

The shaft lengths were measured from the base of the body to the bottom of the threads. The body lengths were measured incuding the bottom mounting nipple.

Ok here we go

Premium Member
2,999 Posts
Discussion Starter #3 (Edited)
Remove old struts from car

The first thing that you will need to do is remove the stock struts.

This is very straightforward.

The car will need to be off all fours, wheels removed.

Brake lines will be disconnected from the struts.

17mm bolts secure the lower mounts

Remove assorted bracketry from the front strut towers (10 and 14mm bolts)

If your car is a GT, disconnect the AAS servos (front and rear).

Remove the rear strut tower bar(GTs only) (14mm bolts)

Youll have to remove the rear AAS servos as they may not fit through the strut tower hole(GTS only) (8mm)

Remove strut assembly (you were reading the FSM for the finer points right?)

Use the spring compressor to relieve the spring tension on the upper perch and mount so you can disassemble the strut. The main nut is 21mm.

The nut may pose a problem for some folks, One..rust can be an issue so be prepared with whatever penetrating oil you prefer. Two…the shaft of the strut is not “keyed” to the top of the strut mount. This means that as you try to turn the main nut it will try to turn the shaft…..forever. An impact gun works wonders here.

Just a quick note here..The springs when compressed have a great deal of stored energy(esp the front springs) so pay heed to the instructions of the spring compressor and ensure that it is firmly attatched. Take it easy and slow here, no sense in getting yourself hurt for no reason.

On to the installation then..

(PS. If this all looks a bit familiar, it is. I am employing a bit of cut and paste from my previous illumina conversion/installation writeup. Yes its a cheat but a good one ;) )

Premium Member
2,999 Posts
Discussion Starter #4 (Edited)
Youll be left with this mess of parts.

The old struts will be used as donor housings for the new inserts. You will have to remove the insides to make this possible.

Inspect and clean the remaining parts. Some points of note:

- Because the 2nd gen Koni Inserts are 1mm wider than the 1st gen specific konis it is important to use AAS struts as donors only. The non-AAS struts will more than likely be too narrow and the insert will not fit. By using the AAS struts as donors you will guarantee that either 1st gen or 2nd gen koni will fit

-If you plan to use lowering springs, the stock springs are not necessary to be kept.
-If you are keeping the stock springs there is a left and right rear spring. Remember which is which. The fronts will be the same.
-The struts, springs and upper perches are indexed by paint to keep them in the correct orientation. Note this and keep this orientation when reassembling the struts.
-Check the strut mounts to make sure they have not been damaged
-Inspect, clean and regrease the strut bearings.
-If you have a GT the likelyhood is you have the red foam bumpstops. These do not fare well over time and get old, dry and crumble to nothing. New bumpstops may be needed. 2nd gen closed cell foam bumpstops or 1st gen non-turbo hard rubber bumpstops can be used.

I would suggest the 2nd gen bumpstops however as they are slightly shorter( Gives a bit more travel. Explanation to come later) and are softer/more progressive than the hard rubber non-turbo stops.


Premium Member
2,999 Posts
Discussion Starter #5 (Edited)

1st gen sports

Euro 2nd gen Sports

(no photo of the 1st gen Specials. Sorry :( )

Now that you’ve purchaced one of the 3 varieties of Koni inserts, youll have to install them in the donor strut bodies that we have just taken off the car.

Konis online instructions:

here you have your (preferably blown)donor struts to be sacrificed to better things.

First thing that needs to be done is to relieve the nitrogen gas that is in the strut.

Naturally a vice, clamp, workmate bench is a great help here. Use a punch to make a nice divot for the first small drill bit in the center of the base of the strut. This really helps the bit from trying to wander all over the place.

Drill pilot hole to relieve gas

If theres a lot of gas pressure, the strut may vent a load of oil/oil vapor at your face. Old shock oil smells/tastes pretty foul( and Ill bet its not that great to get in your eyes either). I used a towel large enough to drape over my hand and the strut without getting in the way of the drill bit. If the strut decided to vent gas/oil it would be caught by the towel and not my face. (the towel is in the picture but not over my hand for the sake of the picture)

Use the pilot hole to empty the strut of oil

It’s a good thing to have a bucket handy for this. When the pilot hole is made, pump up and down on the strut shaft to remove as much of the oil as possible. There wont be as much of a mess when it comes time to chop the heads of the struts off.

Chop the top of the struts off

You can use whatever suits you best here. Rotary tool, Hacksaw, or in my case I used a pipe cutter that I picked up from the local flea market for $5. Worked like a charm. From the top of the weld youll be making the cut about 3/8”-1/2” lower.

Remove/discard internals

Provded you’ve done the cutting well, this part is easy. A couple tugs on the shaft and the internals will slide out.

Drill 1/2”(14mm) hole in base.

(Sorry, no picture)

This is pretty self explanatory anyway. This will be widening the pilot hole made before.

Remove internal obstructions in the strut tube

Just as in the koni instructions, there may be odd nubs/obstructions in the strut tube. Here you see a small indent from the welds on the brake line bracket. This will need to be filed down to clear the way for the insert.

After you have cleaned out the gutted strut housings you can repaint them if necessary(not a bad idea). I used Krylon flat black. Youll wind up with this:


Premium Member
2,999 Posts
Discussion Starter #6 (Edited)
The next step will involve assembling the inserts. But before that gets done the 2nd gen inserts will need to be addressed.

As said they are short, 2” front , 1” rear shorter. They are shorter in both body and shaft length. Because both are shorter the springs will be artificially tensioned and the shaft will be at full extension the majority of the time. It will also limit downtravel of the suspension(tires stay on the road, more control over steering, braking etc).

The quick solution is to extend the length of the strut body with a simple spacer.

These are simple 1” diameter pipe couplings(1.5” long and 2” long) I found at the local hardware store.

They fit over the “snout” of the insert well and add the length that’s necessary . Longer bolts(12x1.5) than what was included in the kit are also needed. All told these simple spacers added 1” to the front inserts and ½” to the rear.

While this wont concern folks who will be using the 1st gen Specials or using coilovers(has adjustable spring perches) or lowering springs (shorter and will not have the struts in tension the majority of the time). Its good info nonetheless.

Premium Member
2,999 Posts
Discussion Starter #7 (Edited)
Now its time to assemble the new units.

Insert the er….inserts into the donor housings.

Now that you’ve sorted the length issues of the 2nd gen sports(or not if you have the Specials), slide them into the appropriate strut body.

The kit will come with rubber dust boots. Slip these over the cut end of the struts. When the insert is fully in, slide the dust boot so it creates a seal between the insert and the strut body(mine came with two only and so I installed them on the fronts).

The inserts attach to the strut with a large M12 x 1.5 bolt through the large 1/2” hole that you made originally. You may have to use the bolt to pull the insert into the strut housing as there will be small bumps on the inset to make a compression fit with the strut. Once the inset is fully in the strut, remove the bolt and use the large washer and lockwasher that is included in the kit. Bolt the assembly down to 55ft/lbs.

Almost there.

Reassemble the strut assembly

Unless you are installing coilovers you are probably going to need this, A spring compressor.

I hear that some lowering springs do not need spring compressors. This may be true, but I cannot confirm this. I was able to compress the rear springs enough to bolt things together, but certainly not the front. For a $6 rental fee, the compressor was worth the money.

The assembly order for the struts will be:

Strut > bumpstop > accordion boot > spring > spring isolator > upper spring perch (and for the front struts) > strut bearing > upper strut mount > lockwasher > nut

Torque down to 65ft/lbs and youll have something that looks like this:

Reinstall in car

Installation will be the reverse of the disassembly process. Set the car down, drive to your favorite alignment shop to have the car looked over/readjusted and youll be on your way to a better handling the twist of the wrist.


Premium Member
2,999 Posts
Discussion Starter #8 (Edited)
Addendum 1

As mentioned the spacers and installation of the European 2nd gen sport inserts will be shorter than that of the same build with the 1st gen special inserts. The combination of spacers I used will have the fronts shorter by an inch and the rears shorter by 3/4”. This is a decent comprimise in my view. Long enough to have the travel necessary to have a comfortable ride with stock springs.



Premium Member
2,999 Posts
Discussion Starter #9 (Edited)
Addendum 2

Strut bearing differences with the GT/non-GT and the 2nd gen inserts. This has been reviewed before in the Illumina installation, but it bears repeating.

There are 2 varietes of strut bearings on the 1st gen. The metal item on the left(found on GTs apparently) and the plastic item in the middle (Non-GT). The item on the far right is a 2nd gen bearing and can be ignored for this discussion

While the metal bearing fits in the upper strut mount and sits on top of the upper spring perch

The plastic bearing fits inside the upper spring perch and around the strut shaft.

Because there is a difference in the end diameters of the 1st and 2nd gen strut shafts, the non-GT plastic bearing will have to be bored out to fit over the 2nd gen shaft.

Premium Member
2,999 Posts
Discussion Starter #10 (Edited)
Addendum 3

Coilovers. If you do plan to run coilovers there are a few changes to be made.

You will be removing the spring perches

The coilover sleeves will rest on the welds, so don’t grind them off unless you plan to have a larger base for the coilover sleeves welded on.

Like so

The rest of the installation will progress much like what was documented in the Illumina install.

Wholy Moly!

How am I doing? Comments? Critiques?

comments here

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