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2008 GRB 20th anniversary 6 MT
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Discussion Starter #1 (Edited)
Will Koni inserts and Eibach lowering springs or Sti pink springs in Forester (Sti) strut housings be an issue or would I be better off using WRX/ISTI strut housings?

The question is regarding the lifespan of the inserts and springs.

It was mentioned here that using Koni inserts on the FXT housings caused the springs to wear (post#7):
http://www.subaruforester.org/vbull...mpreza-fitment-springs-forester-struts-34436/

Also what are the part numbers for the Koni inserts that I need?
I have PMed Porter but he has not been around since January.

Also here it is mentioned that Whiteline springs are not recommended but STi/SPT pink ones
http://www.subaruforester.org/vbulletin/192242-post36.html
Does anyone have the rate if the above 2 springs?

The SG9 Sti pinks (FSTI specific) are 36N/mm front and 34N/mm rear and want to know if they will work with Koni inserts.

Also what are GR2's?

Thanks :)
 

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2017 VW Golf SportWagen 5MT
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If you'll be using your stock tophats, you'd want to use following part numbers:

front: 8610-1351SPORT
rear: 8610-1440SPORT

You can find these on tirerack.com if you specify '07 WRX as your vehicle. The other Impreza-fitment inserts would be for '02-'03 WRX -- fronts will be same part number, rears will be different. Only difference are the threads on top of the shaft to account for a different-style tophat.

Installation instructions for these into WRX housings can be found here.

A few have installed these into Forester strut housings, Porter is one of them. Forester housing is longer than the Impreza housing and the spring perches on the rear struts sit higher up. One problem with that setup is you are limited to a choice in springs since you'd need to run a Forester-specific spring. I've thought of going this route initially but decided to stick with Impreza housing.

Stan
 

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I use 02/03 WRX Koni inserts, with some spacers to make work on the 04 Group-n tophats I'm using fr/rr.

The springs I use are FXT specific Swift springs.

Ride height is about a little over an inch lower all around, if anything I would like the rear about 1/4" higher, for more rake. But other than that, I love the stance it's at.

It's taken me a while to really dial in the right dampening settings for the springs, and a small 1/8 turn will screw it all up, so it's pretty sensitive to adjustment. Come to think of it now, it's a little bouncy currently, and I need to play with it more...

The mention of springs sagging in the other post, I blame on just being Whiteline springs. They are not the highest quality, and historically have many issues not just for the forester, but the WRX as well. Just about every other brand is better, from the subaru bits, to swift. Whiteline's sagging happen more often than not.

I'm going on 25k+ miles, and more than a year with an upgraded suspension.

Other suspension mods I have:
aluminum front control arms with urethane bushings within
whiteline caster bushing
04 STi rear lateral links
rear trailing and lateral arms mix of urethane and group-n bushings in them
whiteline sway bars FR/RR
kartboy end links
group-n top hats front and rear for an 04 WRX.
 

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Discussion Starter #4 (Edited)
Cheers guys.
Teiva-boy, what are the spring rates of the Swifts you are using?

Edit:
Thanks for the installation link Stan, but this worries me a bit:
"You can now see that the bumps that were resting on the strut body have been sucked down into the strut body by tightening that bottom bolt."

Are these little bumps strong enough to withstand the stress and not move further down, hence altering the ride height?!
 

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Cheers guys.
Teiva-boy, what are the spring rates of the Swifts you are using?

Edit:
Thanks for the installation link Stan, but this worries me a bit:
"You can now see that the bumps that were resting on the strut body have been sucked down into the strut body by tightening that bottom bolt."

Are these little bumps strong enough to withstand the stress and not move further down, hence altering the ride height?!
Those bumps are to be sucked in for a reason! They take up the slack of the ID of the strut housing, so that the insert doesnt rattle around inside the strut body.

When you tighten down the bottom bolt, they are not going anywhere. Those insert will stay forever, unless the bolt comes loose. I use locktite, and torque to Koni's specifications per the instructions that come with thei inserts.

As for swift rates, search the groupbuy forum or vendor forum, they are in there.
 

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2017 VW Golf SportWagen 5MT
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Yep, the bumps are supposed to be in and keep insert from moving sideways. The bottom of the insert is resting on inside bottom part of strut housing, it's as far down as it will go. The strut shaft isn't load-bearing anyway, the spring perch is. For insert to move up the strut bottom would have to rip out and car would have to be in the air. They aren't going anywhere.

BTW, I've had these Konis for over 30K. I've used them with RCE wagon springs, Prodrive STi red springs, '05 USDM STi springs and now '05 WRX wagon springs. I once bent the front right strut, sourced another spare strut, gutted it, transplanted the inserted into the "new" housing -- done.

Stan
 

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Discussion Starter #7
Teiva-boy can you post some pics of your car?
Do Impreza springs fit in Forester housings? I guess the answer is no due to the different lengths of the housings?
 

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Discussion Starter #8 (Edited)
One more question: how is the damping adjusted on the Konis?
Is the knob at the bottom of the strut and is access easy once fitted to the car?

Also is the adjustment click-by-click, otherwise how can one make sure that all dampers are set to the same setting when tightening them?

Also, isn't the OEM insert removable from the WRX housing?!
I am pretty sure the front ones are as when I had Prodrive springs fitted to my previous WRX wagon, the garage removed the OEM insert to change the bump stop to the one supplied with the Prodrive springs.

In the NASIOC Koni installation thread it is mentioned:
"If you've got an 04 STi you need to buy some donor WRX struts, any year will be fine (just make sure you get 04+ rear Konis). If you've got an 05+ STi you're SOL because the strut ears are shaped differently than on WRX struts and the Konis wont fit into the STi struts."

Has anyone actually fitted Koni inserts in SG9 Forester housings? Grymes has installed them in a pre-facelift model.
Teiva-boy, is your car pre-facelift model?
I am worried Koni inserts might not fit my FSTI housings as mentioned above about >05 ISTIs.
Or , as long as I get the >04 inserts I should be OK?
 

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One more question: how is the damping adjusted on the Konis? Is the knob at the bottom of the strut and is access easy once fitted to the car?
There is an adjuster tab at the top of strut shaft, you fit a tool over the tab and turn the tool to adjust.

Also is the adjustment click-by-click, otherwise how can one make sure that all dampers are set to the same setting when tightening them?
No clicks, it's free-spinning. You can use marks on the adjustment tool as a reference.

Also, isn't the OEM insert removable from the WRX housing?!
I am pretty sure the front ones are as when I had Prodrive springs fitted to my previous WRX wagon, the garage removed the OEM insert to change the bump stop to the one supplied with the Prodrive springs.
No, they are sealed and aren't meant to be taken apart. You can cut off the top, that's about it.

I wonder if yours were the inverted STi-style struts, those do come apart to access the bumpstops.

We in the US do not have FSTi struts, we don't know what it looks like and what the valving is like. If they are the inverted type, I would skip them for cores and use WRX struts for cores instead. There was a post on Nasioc from someone that fit Koni inserts into the STi inverted struts, I can dig it up if you want.

Stan
 

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Discussion Starter #10
There is an adjuster tab at the top of strut shaft, you fit a tool over the tab and turn the tool to adjust.


No clicks, it's free-spinning. You can use marks on the adjustment tool as a reference.


No, they are sealed and aren't meant to be taken apart. You can cut off the top, that's about it.

I wonder if yours were the inverted STi-style struts, those do come apart to access the bumpstops.

We in the US do not have FSTi struts, we don't know what it looks like and what the valving is like. If they are the inverted type, I would skip them for cores and use WRX struts for cores instead. There was a post on Nasioc from someone that fit Koni inserts into the STi inverted struts, I can dig it up if you want.

Stan
Hi Stan,

OK, I just realised that all those threads on Koni inserts were for non-inverted struts :(
Yes, my 06 WRX had inverted struts so the inserts can be removed. I am not sure about the rears though. Can't Koni inserts be fitted to these?
Yes, I did find a couple of threads on Sti inverted struts but haven't read them all yet:
Koni inserts in STI inverted struts-specs and pics inside - NASIOC
Koni inserts in '05+ STi housings? - NASIOC

It seems like there is a lot of work involved though if I am not mistaken.

On another note, are Tokico's D-Spec ones comparable with the Konis and harder than e.g. ISTI dampers?
Also, are Tokicos complete struts, i.e. not dampers so not messing about to fit?
What springs to Tokico's work best with?

As mentioned in another thread my aim is to stiffen the suspension slightly (currently on JDM FSTI suspension) and lower the car.

The more I search the easier it seems to just get hold of Sti FSTI pink springs and fit those to the second set of FSTI suspension that I have got but if for the same price I can get Tokico struts and a set of springs to match that are known to work well I am willing to try this instead.
 

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None (that I know of) of the USDM regular Imprezas came with inverted struts, those only came on the STis. If the FSTi suspension comes with stiffer, inverted-style struts matched with the FSTi pink springs that some on here are running, that sounds like a good, Forester-specific setup.

Tokico D-specs are a full WRX-fitment strut, not an insert. Quite a few on this board are running them with great results.

Stan
 

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D-specs are great if you want impreza sti ride height. They're cheaper than konis and you don't have to hack up your struts to fit them. IMO the d-specs are a better option than the koni's if you're not competing or anything.

For konis I'd throw them in non inverted wrx strut bodies if you want to be low, or noninverted XT strut bodies if you want taller ride height. If you use forester strut bodies +impreza springs, it will just sit about an inch higher than with impreza strut bodies. I wouldn't use the FSTI strut bodies.

The FSTI inverted struts are very good, I'd probably just throw the FSTI pinks on them and see how that is rather than going to a more aggressive strut. However if they're shot you could try out some other options.
 
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