Will Koni Sport Yellows fit the 6th Gen?

This is what I hope to determine. Thanks to the commitment of da Roo here in the 6th Gen section, he has sent me the funds to purchase a 6th Gen front strut from a 2016 2.5i Premium to cut open to verify whether or not an 8610-1453S or 8610-1447S Koni insert will fit.

My understanding is that the Limited model 6th Gens have a Stablex strut system that has a little beefier strut tube. This is why I ordered the 20310AL03A left front strut. If someone can verify for me that this is NOT a Stablex strut, I would appreciate it.

The Koni front inserts require that the strut tube of the donor strut be cut at a particular length and the internals of the OEM shock to be removed and discarded, leaving the open strut tube for the insert to be installed.

Additionally, the Koni front inserts require a particular internal diameter on the donor strut tubes for them to fit properly. They bolt in from the bottom utilizing a hole that is drilled in the bottom of the strut body. And nubs at the top of the Koni insert's tube are meant to engage the top of the strut tube, deforming it slightly when it is sucked down into the donors strut tube during the process of bolting it from the bottom.

As you can see here, the fluting at the top of the 6th Gen strut is troubling. All of the WRX and Legacy struts that I have installed Koni inserts into have been a constant diameter from the top of the strut tube to the bottom.

I have a 2012 WRX front strut sitting in the garage to compare the 6th Gen strut to. Essentially, with some minor differences in perch height and the attachment tabs for the wheel speed sensor and brake line, it is the same as the 4th Gen and 5th Gen front struts.

I measured from the bottom of the strut, up to the place where I would need to make the cut (long horizontal silver line) and measured the outside diameter of the strut tubes to compare.

As you can see, the OD of the entire WRX strut tube is 2.00 inches, as is the top of the 6th Gen strut tube. But, below the fluting, the 6th Gen strut tube is wider, 2.12".

The question is....is this just a thicker tubing section? Or does the fluting of the OD appear on the ID as well? I will have to cut it up to truly know.

Cutting it will be a challenge because the cut needs to be made in the middle of the fluting as you can see from my silver mark. I usually use a pipe cutter, but in this case I will need to use a hack saw.

Fullah - notice the OD in the 6th gen strut to the '12 wrx (last pic of first post). It is initially the same at 2' towards the top but as you look lower on the pic it bulges outward slightly to 2.12'. Until GT cuts the strut open I don't think you'll get further info on the similarities/differences.

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All of my google searches for the part number have contained a part description stating "Legacy, without stablex susp. Legacy, Outback. Left. 2.5l. Sedan. With eyesight package."

I think this should confirm but it might be worth a quick call to the subaru parts dept for absolute assurance.

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Fullah - notice the OD in the 6th gen strut to the '12 wrx. It is initially the same at 2' towards the top but as you look lower on the pic it bulges outward slightly to 2.12'. Until GT cuts the strut open I don't think you'll get further info on the similarities/differences.

 

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I know he is intending on doing the koni inserts and seeing if they will work but my question was more about the physical dimensions of the strut mounting between the two rather than the internals. Basically what I was trying to figure out is if a coilover made for a 2012 wrx would physically bolts up to the 6th gen. It seems like based on what he posted about it being similar to the 4th and 5th gen that this may be a possibility on those model years. I was trying to understand why it's different for the 6th gen.

I know he is intending on doing the koni inserts and seeing if they will work but my question was more about the physical dimensions of the strut mounting between the two rather than the internals. Basically what I was trying to figure out is if a coilover made for a 2012 wrx would physically bolts up to the 6th gen. It seems like based on what he posted about it being similar to the 4th and 5th gen that this may be a possibility on those model years. I was trying to understand why it's different for the 6th gen.

So in order to make a reasonable guess as to whether or not the Legacy strut's tube is made from a thicker wall tubing, i decided that comparing weigh would give me some clues.

The WRX strut weighed 10.1 pounds.

The Legacy strut weighed 11.2 pounds.

It would seem that the increased weight IS a result of a thicker tubing section. I will proceed to cutting it open to know for sure. Fingers crossed that the ID is consistent down the entire strut tube length.

Bump. Need to get my xmas list together. [emoji51]

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Bump. Need to get my xmas list together. [emoji51]

 

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Since I can't use the pipe cutter because the cut needs to be made on the fluted section, I have to finally buy myself a good sized bench vise. Gonna need to use the reciprocating saw to cut this baby open. Give me a few days more and we will have some answers.

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Bump

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Good news gents! I believe that Koni inserts WILL work in the 6th gen front donor struts!

Today I cut open a 6th gen strut, and found that the taper on the outside of the strut follows the same tapered profile on the inside as well, so my initial reaction was disappointment because that meant that the strut tube was too large for the Koni.

However.... This little sleeve has been included with every insert that I have ever bolted into a Subaru strut, and I never used it, because all those struts had a 45mm ID strut tube.

But....look at this pic of the little instruction sheet that came with the Koni....the sleeve is to be used with a 48mm ID strut.

And sure enough....the 6th Gen strut tube ID measures 1.890", or 48.006mm! Bingo!

So....I just need to clean up the cut I made on the strut, determine the optimal length to bring the strut tube to so that the sleeve sits all the way inside the tube and the Koni's nubs get pulled about 1/4" into the sleeve, and bolt a Koni in.

Okay, so I cleaned up the top of the tube on the belt sander and the optimal inside dimension from the bottom of the tube to the top is 11-7/8", just like the 5th Gen. Bottom is drilled and the sleeve is inserted and fits nicely. Time to buy and cut the right side strut and actually bolt some Konis in and get them on a 6th Gen.

Which insert model number did you use..and will this work on the limited models with the stablex suspension?

We tested the strut w/o stablex so you would need 2 premium struts

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What about rears?

8610-1453S Koni

We tested the strut w/o stablex so you would need 2 premium struts

 

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Correct, the Stablex struts would be removed and premium standard struts used for donors for the Koni inserts.

So I found this about the stablex...

STABLEX-Ride has been employed for premium grade models. New valves and larger diameter front strut cylinders have improved damping response at low pistonspeeds and permit damping suppression at high piston speeds, resulting in even more stable steering stability and comfortable ride quality.

Does this mean that the filler ring you inserted into the strut tube wouldn't fill the extra space, because it's a larger diameter, or does the extra space not matter?

So I found this about the stablex...

STABLEX-Ride has been employed for premium grade models. New valves and larger diameter front strut cylinders have improved damping response at low pistonspeeds and permit damping suppression at high piston speeds, resulting in even more stable steering stability and comfortable ride quality.

Does this mean that the filler ring you inserted into the strut tube wouldn't fill the extra space, because it's a larger diameter, or does the extra space not matter?

Hey Joe,

It's been awhile! Thank you for testing out the 6th gen struts. Definitely interested in this. Do you know if this would work with the 17 outback struts? If I remember correctly they're the same as the legacy, except for the perch is welded a bit higher.

Also the Subaru part site shows the rear shocks are different part numbers between the OB and Legacy.

I'm looking into purchasing the new Rs-r springs that came out for the OB and the Konis would be perfect for them.

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