Build hybrid Koni strut? (Page 1/4)
hobbywrench NOV 05, 12:00 PM
My 87 GT needs shocks and I want Konis...problem , right. A number of hobby folk have adopted later (available) strut inserts into their strut tubes. Experienced with "reds" in NIssan and "yellows" in MR 2 it seems a reasonable route. Anyone do it? An unknown is "jounce" compatibility depending on donor selection? Then height, top press-in dia, and taper . The "fit" inside the strut tube is mostly at the strut top cutoff. Also the bottom "dome" must be strong enough for around 55 ft lbs of the anchor machine screw. I hope to find some Koni drawings somewhere. Otherwise it's an expensive crap shoot. Thoughts?

[This message has been edited by hobbywrench (edited 11-06-2020).]

qwikgta NOV 05, 03:41 PM
there is another thread about this somewhere else on Pennocks. Also, you can check YouTube, it shows a video of someone cutting up a stock strut and installing the koni insert.

Rob
Craig71188 NOV 06, 07:41 AM
I called Koni tech about their performance inserts. They are made/sized for specific applications - and none are right for the Fiero. In doing some research, it appears that "maybe" a Neon F strut could be used at the rear. The fronts are very short and lowering the car only makes it more challenging to find an alternate shock. SO far I have one set of Koni's on the race car, keep looking for another "good used" set for the second chassis. KYB Gas-a-just would be worth a try, but no rear option....
Will NOV 06, 07:44 AM
There's also been limited investigation of building inverted struts using Bilstein cartridges, which can be easily revalved.

If you can find a Koni insert that has the right dimensions, the Koni Custom Shop (and other builders) can revalve it to whatever you want.
Iain NOV 06, 09:04 AM
What Will said.

It's actually not that difficult to build Bilsteins, but you do need to be able to weld to a good standard. If you use s/h inserts you'll likely need to fabricate, or buy, new top mounts.
Gives you much better control of ride height and valving though.

You need the bottom brackets from a pair of struts.
Conversion tubes with spring seats.
Inserts. (40mm inverted monotube)
Springs.
Top mounts. (optional)





NOT cheap!

[This message has been edited by Iain (edited 11-06-2020).]

Will NOV 06, 09:25 AM

quote
Originally posted by Iain:

It's actually not that difficult to build Bilsteins, but you do need to be able to weld to a good standard. If you use s/h inserts you'll likely need to fabricate, or buy, new top mounts.
Gives you much better control of ride height and valving though.

You need the bottom brackets from a pair of struts.




If you're bulding from scratch, you don't need the brackets.... a pair of profiled/drilled plates and a couple of reinforcement pieces would make a new taco clamp from scratch.
hobbywrench NOV 06, 02:18 PM
A survey of the "cut-a-strut" versions from Koni online shows a fairly large inventory still available for cars back to 80's ranging $144 to $200 ea. These are the style with the protruding female, internally threaded nipple which abuts inside the bottom of the strut tube which is clearance drilled for a grade 5 locating bolt. In this version the top of the strut insert is located via "bumps" on the outside of the insert which are pulled in at final fitment by the screw at the bottom, thus press- fit- locating the strut insert. The Fiero strut tube would be gutted and cut down to a suitable length. The first important dimension is the OD of the Koni inserts and this is not readily available. I need to know the ID , tube length of an 85-87 strut tube. Anyone measure a loose unit? That would provide some kind of start. Then a conversation with the Koni vendors to weedle out a measurement from them (good luck). . Yes, this exercise is fraught and potentially a costly try and discard....ha ha.

The other styles of Koni inserts seem to be the OEM threaded top style and the "Sport" which is for custom enclosure. (I am winging this from pictures).

The OEM threaded top style shown on e.g., BMW sites is a slip- in with a cap mating with either internal or external threads on the strut tube top. The 2 Sport style customs show dimensions off a (Koni?) drawing . I cannot see (pics) how this insert is retained , except one site mentioned a "stud." These Sport versions run $200 ea.

There is some price discounting on the older cut-a strut styles . I count 17 different Koni part numbers in stock. One would likely work. Break the code!

[This message has been edited by hobbywrench (edited 11-06-2020).]

Iain NOV 11, 11:43 AM
These are new Bilstein option:

https://streetwiseparts.com...l-motorsports-struts

Not cheap at US$600 each

For info, mine are S/H Ford Escort Mk1/2 , I have both Long and Short, the Short are a better match lengthwise to Fiero strut length.
hobbywrench DEC 03, 12:07 PM
Haven't stopped on this topic. One finding is the bad PDF data base dimensions for the rear 85 GT Fiero struts such as body length. It seemed weird from the start being stated as 8 inches . I measured 13 odd inches on my lowly (but working ) Gabriels. This puts any hybridization more within reason for the cut-a-strut idea. These old Gabriels work on my lowered car inhibiting motivation just now. Really need the ID dimension to advance on possible candidates from various Koni donors...Don't know whether to trust a Gabriel ID to be OEM Fiero ID so as to baseline .

[This message has been edited by hobbywrench (edited 12-03-2020).]

msweldon DEC 03, 03:46 PM
To add to this discussion. I'm currently driving toward installing the koni generic dual adjustable inserts into a stock fiero housing. These will require the stock housings to be cut and a gland nut adapter welded to the top. I found some near perfect koni gland nut adapters from a speed shop in Australia and currently having the ID turned to 2.005" to fit the fiero strut.

If you'd like to know more let me know...