KONI Sports for Classic Z's

[khughes]

33 minutes ago, Zed Head said:

Yours does not look the picture in post #1 or on MSA's web site.  You said that you bought them from "Z Car"?  Is that a typo?  It's Motor Sport Auto or theztore.com. 

There's no projection on the bottom in their pictures.  The part number seems different too, 29-2021.  Not sure if that has meaning.

 

@Zed HeadSorry yes.. that was a total typo.. meant the Z store (Motor Sport Auto) 🙂

I had noticed that the photo on their website didn't match and that mine didn't match the earlier pics on this thread.. i presumed that it was most likely a revision in design.. but you could be right.. maybe they are just plain wrong parts (none of the pictures of the Koni's listed at MSA seem regardless of model/year appear to show this little spacer)

I will most definitely check with MSA to see if these are correct before i start hacking at them. Just for reference.. here are the stickers on the box 

@Patcon thanks for the tip.. that sounds like it will be an easier job than hacking at them.. is there any danger with heat build up in the tubes when using a flap disc? i havn't done anything like this on shocks before and dont want them blowing up in my face 🙂

Edited September 26, 2022 by khughes

[Patcon]

I agree, don't put alot of heat into them. Cut a few seconds, let them cool, cut a few seconds...

A 36 or 60 grit pad will give you the mm you need pretty quick

[cruceno21]

I just did these on my 280z, and I accidentally ordered a replacement strut for a 240z, and I know none of the ones I got (front or rears for my 280z, or the one rear for a 240z) had that bump. Check the part number on the part themselves also not just the box. So you might have the wrong part. Remember the rears and fronts are different parts as well. Good luck. 

[Joseph@TheZStore]

On 9/25/2022 at 4:32 PM, khughes said:

Hi Guys, 

I bought a set of the Koni Sports from Z Store, and finally up to the point of installing them but it hasn't gone that smoothly. For the fronts I bought the 23-1031 (8641 1031SP1 on the Koni Box with a manufacture(?) date of 31/08/21) and i am not 100% sure what my front struts are out of (as i bought a second hand set, original length with GC coilovers and Tokico BZ3038's) but i am sure they are 240Z/early 260z. The rears went in all ok (well.. after dealing with a dent in the rim of one of my rear struts right on the thread courtesy of my powder coater).

The fronts i am having difficulty and it seems to echo the issues earlier in this thread. One front strut i can barely get a 1/4 turn on the gland nut before it bottoms out, at which point the underside of the gland nut to the strut measurement is 8.7mm, on the other side i can get it maybe a full turn, with the measurement being 8.2mm (kind of similar to previous posts). My Koni shocks have a small welded in spacer at the bottom which is about 4-5mm deep.. presumably to overcome issues with any welding beads inside the tube.. this seems to be very close to the additional clearance i need to get the gland nuts on properly. I have not seen mention of this little spacer in previous posts so i am not sure if its an early revision or something (i hope they are the right shocks!). Comparing the outgoing tokico's to these, the bottom spacer appears to be the cause

I am a little sceptical that the revised gland nut with the tapered inside edge will do much in this instance as in previous posts it seems to only give 2mm, and wondering if i can just lop 4mm off the bottom of this spacer thingy? i should still have what looks like a build up of weld just under the tube and above the spacer as a bit of a safety from breaching the tube.. can anyone forsee any issues with this (unsure how i go about cutting it.. hack saw i assume)

I am yet to contact MSA (purely because its still weekend over in the US - i am in Australia), but will do as well.. Just hoping someone else has come across the issue and a fix is simpler than waiting for more parts to arrive from the US.

Thanks

Kent

Hello Kent. Those are the correct strut cartridges for a stock 240Z front strut housing/hardware. Unfortunately they are not designed for Ground Control coil over kits. GC sells specific cartridges to fit in their kits, and whatever cartridges they are labeling as "Koni Yellow" are not the same as our Koni Sport (Yellow) struts, so they are either a different type of Koni strut (not Koni Sports), or they are from another application entirely (BZ3038, for instance, were for 280ZX front). Even though they do not section the strut housing to shorten it for lowering the car (assuming that is what you meant), that doesn't mean the whole kit hardware is designed for "stock" 240Z strut cartridges.

In addition to the height of the cartridge, the cartridge you need is also dependent on the strength of springs you will be using with the coil over kit. Do you know the springs that are on the second hand kit you purchased? I'm not sure if anybody who has ordered the Ground Control kit can tell you what number of Koni strut cartridge they were sent from GC, but they are not 240Z front Koni Sport Yellows as we sell.

If you are not racing this car, and want to use these with your Ground Control front coil over setup, and your measurements indicate that removing part of the "nub" would be enough height, then it is possible, although not recommended, and one would need to be very careful. The warranty would be void for modifications, just like it is for racing applications, so consider carefully if you decide to use these for a custom setup. Here is what a qualified technician said:

Quote

As for grinding off the nubs entirely for a custom length fit, that is probably okay so long as he can do it without generating extremely high heat for very long at that site.  Better to use a cut-off wheel or similar instead of just leaning in on it on a big stone grinder wheel.  Just stopping part way through to cool it off by dunking in some water might not be a bad idea to keep the heat down to avoid compromising the seal or coking the oil and creating internal particulates.

Again, if this is a race car, or you have a specific level of "race" type performance in mind, Ground Control has strut options designed to match the "race" strength of the springs, AND fit with their specific hardware/camber plates/etc.

Let us know what you decide and how we can help.

[khughes]

Thanks @Joseph@TheZStore for the confirmation that they are the correct inserts (phew!), your advice and appreciate you asking around on the cutting/cooling for this situation.. it looks like that is my best option (and thank goodness they have the nubs to grind down to give me those needed few mm's!)

Your 100% correct in that the history of modification done on these struts are entirely unknown, and i certainly don't see it as a fitment issue that would apply to anyone else's situation. I did do some research prior to confirm they were standard length (and there is certainly no sign of cutting either, on the tube or the top threads ), but having not modified them myself i can only guess!

There was limited option in adjustable standard length shock inserts (i understood the GC option to be for sectioned struts), and i am still very grateful that you have developed this option for us! I am also very thankful for the information and support both yourself and Lee from Koni has added in this thread - its a rare opportunity and part of the reason i went down this road.

as a side note - The car is not for track, just trying to clean up and mildly upgrade what i can to enhance it's on-road personality.. The GC kit came to me second hand with the tokico's and 300+ lb/in springs, it had clearly been track focused and unsuitable for my needs (i never ran them this way, just started rebuilding them when i got them). On advice from GC, i have new 150/175 lb/in springs going in to try and keep things within a comfortable range of standard, hopefully this suits the intended Koni shock performance curve.. i am pretty sure i will be happy with them once its all together!

Thanks

Kent

 

Edited September 27, 2022 by khughes

[Joseph@TheZStore]

18 hours ago, khughes said:

Thanks @Joseph@TheZStore for the confirmation that they are the correct inserts (phew!), your advice and appreciate you asking around on the cutting/cooling for this situation.. it looks like that is my best option (and thank goodness they have the nubs to grind down to give me those needed few mm's!)

Your 100% correct in that the history of modification done on these struts are entirely unknown, and i certainly don't see it as a fitment issue that would apply to anyone else's situation. I did do some research prior to confirm they were standard length (and there is certainly no sign of cutting either, on the tube or the top threads ), but having not modified them myself i can only guess!

There was limited option in adjustable standard length shock inserts (i understood the GC option to be for sectioned struts), and i am still very grateful that you have developed this option for us! I am also very thankful for the information and support both yourself and Lee from Koni has added in this thread - its a rare opportunity and part of the reason i went down this road.

as a side note - The car is not for track, just trying to clean up and mildly upgrade what i can to enhance it's on-road personality.. The GC kit came to me second hand with the tokico's and 300+ lb/in springs, it had clearly been track focused and unsuitable for my needs (i never ran them this way, just started rebuilding them when i got them). On advice from GC, i have new 150/175 lb/in springs going in to try and keep things within a comfortable range of standard, hopefully this suits the intended Koni shock performance curve.. i am pretty sure i will be happy with them once its all together!

Thanks

Kent

Thank you Kent. By the way you described it, and with the springs you mentioned, I believe you'll be very happy with the range on these cartridges.

Be extra cautious in regards to overheating the struts, and if you've not done anything similar before, it might be worth checking with a technician or machine shop who has. The key things are a sharp wheel, level cuts, and cooling it down often. Heat could really screw up what is in that cartridge just a few mm away. Let us know if you have any issues.

[khughes]

Thanks Joseph, 

I took a hack saw to just on 4mm of the nubs last night and they sit nicely in the struts now.. just need to level off the cut a tiny bit on the weekend which should add minimal heat i hope, hopefully just a quick rub with a flap or grinding disk 

[Zed Head]

19 minutes ago, khughes said:

hopefully just a quick rub with a flap or grinding disk 

If you cut it with a hacksaw then a hand file should finish it off.  We're all so surrounded by power tools now, especially those with the new high power batteries, that the old basic human-powered hand tools often get forgotten.  The hacksaw was the right first choice.  Minimal heat, not too much work.

[JagoBlitz]

On 4/7/2021 at 11:19 PM, KONI Lee said:

Actually Joseph and I have been talking on the phone about this during recent posts.  Lapriser had as also reached out to our KONI tech staff at info@koni-na.com, which is what we would prefer that you do if you have a technical issue such as this.  I also saw the post notification when it popped up on the forum.

First off, clearly I am sorry to see of the issue that had occurred with the stripping of the threads during installation.  We (KONI and Motorsport Ind.) have already made a plan to get a new replacement unit sent out to lapriser at no charge listed officially as a "customer courtesy" replacement due to an installation error that hopefully we can all use a teaching/ learning example and not actually as a warranty situation caused by a product manufacturing issue.  

Looking at the photo, it is pretty clear that the nut was not cross threaded from the beginning as the threads are only truly destroyed down in the area where the nut sits in the tightened position.   The instructions state that the nut should only be tightened to 37 ft./lbs. which is where we feel that things went wrong here. Normally we only see issues of mounting threads being stripped in place (it is quite uncommon though) when someone uses an air or electric impact tool and bangs away to a much higher torque and also gets the very common side effect that the damping adjuster tab and mechanism also gets jammed from the hammering effect of the impact tool.  Although the adjuster did get stuck in this case, lapriser did state that he had only used hand tools so must have been solely from manually tightening to much greater number than recommended.  Of particular note, the top mounting threads used by the Z cars are use  D -shape on the quite small in diameter (12mm vs most strut mount threads at 14mm) with a pretty fine thread 1.25 pitch.  The flat area of the D means that about 25% of the circumference has no threading which will also mean that there a not a lot of threads available to hold excess torque without damaging the threads.  The D -shape is required by Datsun's upper mount shape which was not uncommon in the 1960s and 1970s but went away for the vast majority of cars after that and now 360 degree threads are the norm for several decades.  Extra care should be used if you are installing the D - shaped mounting pins in a spherical bearing camber plate as well that doesn't have the D -shaped mounting hole.

 

Hello Lee,

you mentioned this case where you do not have a top hat with a D shaped mounting hole.
What is the best practice here? I am scratching my head how to prevent the damper shaft from spinning freely... especially with the nylon lock nut it is very difficult to fasten it.
Is there a special tooling for this to hold everything in place and prevent damage?
Thanks.

Edited January 1, 2023 by JagoBlitz

[JagoBlitz]

On 1/1/2023 at 12:02 PM, JagoBlitz said:

Hello Lee,

you mentioned this case where you do not have a top hat with a D shaped mounting hole.
What is the best practice here? I am scratching my head how to prevent the damper shaft from spinning freely... especially with the nylon lock nut it is very difficult to fasten it.
Is there a special tooling for this to hold everything in place and prevent damage?
Thanks.

Does anybody else have an idea how to assemble this without an impact gun?

[jonbill]

cut flats high up on either side of the strut shaft and hold it with an open spanner. 

[Joseph@TheZStore]

On 1/1/2023 at 3:02 AM, JagoBlitz said:

Hello Lee,

you mentioned this case where you do not have a top hat with a D shaped mounting hole.
What is the best practice here? I am scratching my head how to prevent the damper shaft from spinning freely... especially with the nylon lock nut it is very difficult to fasten it.
Is there a special tooling for this to hold everything in place and prevent damage?
Thanks.

Hello JagoBlitz, while Lee is currently unavailable, he did get the Koni engineers to confirm. They said if you are using some coil over or other custom top or replacement for the mounting insulator, which does not have the "D" shape, if it has room for two additional nuts at the top, you can "lock" those together to hold the shaft, and use special wrenches to tighten the nut below them. However we would add that since many or most custom setups won't have enough room for 3 nuts, then jonbill's suggestion is a good one. We also know of some who have used strong hands and gloves to simply "hold" the shaft in place. Many have tried a "protected" pipe wrench, which is not recommended.