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jwbrockman:

Andy, could you (or anyone, for that matter) please elaborate on the koni coilover sleeves that you spoke about for the Miata?

I have a '93 that I am prepping for STS2, I have ordered Koni race valved fronts and sports for the rear, where I will be using the NB mounts as you describe. I already have a set of 2.5" springs, so I don't need or want to order a full set of GCs, but those and ebay sleeves are really the only coilover sleeves I can find any clear info about on the internet. I will just use ebay sleeves if it comes to that, but I'd like to know more about the Koni adjusters that you used, such as specifically which part number I will need to fit my car, and how much they should cost per corner. I like the idea of being able to run either 2.25" or 2.5" springs with a spacer, that would make it much easier to find cheap used springs as I test out different rates :). I'm sure the Koni adjusters are also a much cleaner install than the ebay style. Also, if anyone has any recommendations on bumpstops that would be very helpful as well.

Look here.  The motorsports catalog is online. 

Koni Web Site

If you need specific assistance, you can call them direct, or use a retailer like Chris Shenefield at Redshift Motorsport, or Sam Strano at Stranoparts.com

I don't have part number for you because I used the Koni sleevs on my STS Civic, not the Miata (used thread-body 28 series Koni race shocks there).  Part # may be the same as for the Civic, but you should check to be sure.

--Andy
 

Update for Houston Tour, includes 15" vs 16" Bridgestone testing.

--Andy 

JW, sent you a PM on this

Chris

Thanks for the responses. 

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

jwbrockman:

To those who have used the Koni sleeves on a Miata, what do you do for top hats?

Top Hats? I let the top of the spring bang up against the top mount. Hasn't been a problem. I first used Koni Yellow Sports with GC sleeves and bottom perches with 2.5 inch springs and later used Koni 2812 shocks with 2.25 springs. Both setups used converted NB top mounts.

FWIW, the GC pinch bolt is easier to work with in a fendered car than the jam nuts on the threaded Koni bodies. Some folks have corrosion issues, but if you take the time to either spread a little antisieze or dry moly spray on them you won't have problems.

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Aut tace aut loquere meliora silentio.

Ok then, that makes things easier :). I take it the stock rubber isolator will fit on the 2.5 spring?

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

You should make your own NB mounts.

http://www.cardomain.com/ride/2343497

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Aut tace aut loquere meliora silentio.

Thanks a lot for that link, that's a great writeup! I was planning on doing what Andy shows on the GRM website, since I have a bunch of ES swaybar endlink bushings hopping around my garage anyway, but I might follow yours now :).  I have NB mount plates and lower washers on the way from Mazda Motorsports now.

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

OK, I just got my Konis today, and I have to say I'm still confused. I'm just going to use the NA front mounts as is for now. But I do have two NB mount plates that I would like to use for the rear if I can figure out how. Modernbeat, you say that you just let your springs hit the NB top plate, but the writeup you linked to shows that you used GC top perches glued to the mounts. Since GC would not sell me those, I don't have them. So is a top perch of some sort necessary? Currently I have none, just the shocks, Koni sleeves and perches, and the NB top plates. I could basically copy that writeup with the exception of the upper perches, although cutting up lugnuts and then having to modify the adjuster seems somewhat inconvenient, and difficult with my limited equipment.

Since it appears simpler, I am inclined to follow Andy's writeup, but I am also very confused about how his solution works. I ordered the NB plates and cupped lower washer as shown in the post, but I really don't understand how the lower washer can be used. First, it doesn't fit over the threads on the end of the shock. Second, it does not fit inside a 2.5" spring. So I guess I am missing something about how the NB lower washer is used in that plan. Andy, did you use an upper perch of some sort for the spring?
 

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

jwbrockman:

Since it appears simpler, I am inclined to follow Andy's writeup, but I am also very confused about how his solution works. I ordered the NB plates and cupped lower washer as shown in the post, but I really don't understand how the lower washer can be used. First, it doesn't fit over the threads on the end of the shock. Second, it does not fit inside a 2.5" spring. So I guess I am missing something about how the NB lower washer is used in that plan. Andy, did you use an upper perch of some sort for the spring?
 

How big of a diameter is your washer?  Mine are about  1.5", which fits easily inside a 2.5" spring (or a 2.25" spring).  It should be about the same diameter as the recessed area of the upper NB mount.

I did not use any sort of upper perch beyond the NB mounts.  The spring will sit there just fine.

On my shocks (Koni 28) the threaded part of the shaft was machined down to the diamater of the OE shock shaft, so yours may be a tad thicker. You may have to drill the hole in the washer out a bit to fit over the threaded end of the shock shaft.  It will then rest on the shoulder of the shaft.  The bushing goes above that, and then put that up through the NB mount, then another bushing, generic washer, and nut.

 --Andy

PS: Here's a higher res version of the pic in the blog (click on it below).  You can see the diameter of the washer vs the 2.25" spring i.d..  Also, check out the shoulder on the shock shaft.  Yours will be different, but the effect will be the same.
 

Thanks for the response! At least I am not worried about finding spring perches anymore. Unfortunately, I believe I've ordered the wrong washer from mazda. I ordered the lower washer from the NB mount assembly, but it appears that you have used the upper washer from the stock NB assembly in the lower location. Hopefully I can find the correct washer or a suitable substitute in the next couple days. Basically all I need is a wide washer that will sit on the shoulder of the shock rod, that is wide enough to engage the bumpstop, correct?

 Apologies for the poor cameraphone pics, it's all I have right now.

 

 

One more question - what is that black donut sitting in between the washer and the spring in your pic? Is it a cut down stock bumpstop?  

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

jwbrockman:

OK, I just got my Konis today, and I have to say I'm still confused. I'm just going to use the NA front mounts as is for now. But I do have two NB mount plates that I would like to use for the rear if I can figure out how. Modernbeat, you say that you just let your springs hit the NB top plate, but the writeup you linked to shows that you used GC top perches glued to the mounts. Since GC would not sell me those, I don't have them. So is a top perch of some sort necessary?  

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Aut tace aut loquere meliora silentio.

jwbrockman:

One more question - what is that black donut sitting in between the washer and the spring in your pic? Is it a cut down stock bumpstop?  

Yes.  Cut-down bumpstop.  You want it to contact just enough to keep the a-arm from contacting the body.  Some putty at the contact point and a jack to move the shock up and down (sans spring) will show you just how far you can go.  Remember to allow for some bumpstop compression.

--Andy 

jwbrockman:

One more question - what is that black donut sitting in between the washer and the spring in your pic? Is it a cut down stock bumpstop?  

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Aut tace aut loquere meliora silentio.

Yeah, my threads are shorter. But I think I've come up with a stack that will work, using a bushing from an E36 rear shock mount cut in half. If not, the lugnut method will be my plan B :).

 BTW, a nice sharp 7" Santoku makes quick work of filet'd suspension bushing :). 

I plan on using the foam bumpstops in front, and cutting down the stock stop as appropriate in the rear.
 

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

JW, before you risk ruining your shocks, read these threads on Miata.Net. Particularly the first two where folks tried to make some similar to Andy's. The risks you face when making a top mount are that you may allow the shock head to bottom out inside the body if you don't use a spacer, that the threads will get chewed up if the shock shaft and bushings shift on the mount, or that the bushings and washers won't have enough compliance and will either bend the shock shaft, or *** the head within the body causing excessive wear or failure. On the Koni Race shocks the body is long enough, and the shaft short enough that they won't bottom out. So don't add the spacer if you make your own mounts. All the other potential damage is real, and has happened to others when they didn't have enough bushing compliance or shaft protection. The DIY mounts I built out of easy to find parts addresses all those concerns.

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Aut tace aut loquere meliora silentio.

modernbeat:

JW, before you risk ruining your shocks, read these threads on Miata.Net. Particularly the first two where folks tried to make some similar to Andy's. The risks you face when making a top mount are that you may allow the shock head to bottom out inside the body if you don't use a spacer, that the threads will get chewed up if the shock shaft and bushings shift on the mount, or that the bushings and washers won't have enough compliance and will either bend the shock shaft, or *** the head within the body causing excessive wear or failure. On the Koni Race shocks the body is long enough, and the shaft short enough that they won't bottom out. So don't add the spacer if you make your own mounts. All the other potential damage is real, and has happened to others when they didn't have enough bushing compliance or shaft protection. The DIY mounts I built out of easy to find parts addresses all those concerns.

http://forum.miata.net/vb/showthread.php?t=190339

http://forum.miata.net/vb/showthread.php?t=194081

http://forum.miata.net/vb/showthread.php?t=178521

http://forum.miata.net/vb/showthread.php?t=180594

http://forum.miata.net/vb/showthread.php?t=224823

And an informercial about the mounts:

http://www.fatcatmotorsports.com/FCMmounts.htm

From what I can tell, none of these guys replicate my method completely.  The key is to use the sawed-in-hald-sway urethane sway bar bushings instead of NB rubber bushings.  This accomplishes two things: 1) The bushing has a nipple which fits nicely down inside the NB mount hole and, when tightened down, provides a centering mechanism for the shaft which protects it from metal-to-metal contact.  2) The small diameter of the bushings allow for a small diameter washer which will not contact the NB mount itself.  As long as tightening torque is done carefully, there s plenty of side-to-side compliance in the bushings to prevent shocks damage.

I've been running this setup now since well before others made there's (CSP first and now STS2), and never had a problem.  Its been almost six years.  The shocks shafts show no abnormal wear.

BTW, I'm not trying to "sell" anyone on this.  I really don't care what people end up doing.  I just don't want to get labeled as promoting something which does not work.  It works fine so long as it its done completely.  Same with Jason's method.   

--Andy 

Andy, I avocate the lugnut mounts for yellow shocks based on the small size of the head leading to the ease of cocking the shaft leading to a damaged head and or scored shaft. By having the lugnut base bottom out against the lock washer you can guarentee that the lugnut holding the shock to the mount is tight, while only preloading the bushings a minimal amount. That allows the bushings to be more compliant to the shock's angular movement and still protect the threads from being cut up, the shaft from bending, and the head from cocking within the body. You also get to use taller bushings which adds to the compliance. The downside is that it's a little bit heavier, you have to do a little more fabrication, and the adjuster is recessed.

The problems become less important as you restrict movement by using stiffer springs, as the shock has less angular travel and requires less bushing compliance.

 FWIW, my DA shocks are set up exactly like yours, nippled bushings and all.

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Aut tace aut loquere meliora silentio.

I actually took an hour or so before work this morning to hunt around for parts, and I managed to find everything to do it Jason's way. It does seem like this will be a more robust mounting than what I had come up with last night. I wasn't able to find the exact Cragar washers that you used, but a 3/4" cut washer from HD fits over the shank of the lugnut perfectly for the upper washer. For the lower washer I will drill out a swaybar endlink washer like you did (which reminds me, one thing that confused me about your writeup was that you mentioned using a drilled out swaybar "bushing", and I now realized that you meant the washer, not the bushing. That really threw me when trying to figure it all out). 

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'93 Miata - Prepping for STS2
'98 BMW 328i - Daily fun

jwbrockman:

..Actually, a lot of e36 aftermarket rear shock mounts work very similarly to Andy's method, but with an important difference - they use a metal sleeve over the threads of the shock rod, so that the plate can't damage the threads of the shock. I think that type of mounting could work fine on a yellow, with a short 12mm i.d. sleeve for protection of the threads. In my case, it was easier to find the lugnut parts than a 12mm sleeve. 

Yep, my Chevy truck uses front top shock mounts with the sleeve too. The difference between the Chevy/BMW and your NA Koni Yellows is that you don't have enough thread to sandwich everything you want to have in there. That's where the lugnut comes into play. The sleeve is threaded and the nut part extends above the threaded shock shaft.

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Aut tace aut loquere meliora silentio.