True coilover upper perch/mount

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Old 01-21-2009 | 03:57 PM
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Default True coilover upper perch/mount

What about it? That seems like something simple enough and beneficial to everyone. A true upper mount that maintains the same shock and spring angle!




Old 01-21-2009 | 04:30 PM
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Yea that seems like a snap to do. I understand the need for it to move, but this just kind of jarred things in my head a bit. When you mount a strut tower bar, doesn't that further reduce the angularity that you can get with the shock? Seems like a strut tower bar would modify the effective spring constant. Though I'm not sure which is more prone to the deflection, the thin shock towers or the flimsy looking shock interfaces.

What is a reasonable price to pay for this? (I have to ask or I don't know what materials/ processes to start from, or if its worth it)

Market? How many people would by this?

Whats the performance increase? (maybe tied to what I was first talking about)
Old 01-21-2009 | 04:31 PM
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like the FM upper mounts with spherical bearing? same right?

ps move the shock shaft mounting point up like the NB mounts.
Old 01-21-2009 | 04:39 PM
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No. The FM mounts don't have the upper perch separate from the actually mount, so the spring is require to bend with the suspension arch. The OE upper perches/mounts actually achieve this to a degree - better than the FM pieces for sure since the OE pieces do flex. Technically what you see above is the proper way to do a coil over.

We used the above assembly with a custom built tube shock using bilstein pieces, that was shortened just over an inch. The results were phenomenal and bullet proof.

The arguments against this for cost would be that the Miata suspension has so little travel that the spring flex/bend is nominal and doesn't really effect performance. BUT if you were to combine what you see in the photos with some increase for travel using off the shelf shocks, you might have an argument for sale. But cost against competing product is your target.

Just throwing ideas out there because I know you're looking for something to do.
Old 01-21-2009 | 05:11 PM
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Basically I see one turned piece with a 2 piece aluminum housing ontop which traps the spherical joint of the turned part that sits around the shock extension, and is secured with a nut to the housing, which is further secured with another nut for paranoias sake. Is that what's going on here?
Old 01-21-2009 | 05:23 PM
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That sounds right. The top perch isn't technically secured by any nut, it's trapped between the spring top and the spacer/ring that sits between it's top and the bearing.
Old 01-21-2009 | 06:03 PM
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I seeeeee, I didn't look hard enough at the disassembled. Maybe you could make a post, and see who would want one.
Old 01-21-2009 | 06:14 PM
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Depending on the price, travel, and compatability I might be interested in a full package later in the year.
Old 01-21-2009 | 06:55 PM
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oh that's right, the FM perches bend the spring. as do the TEINs et al.

my issue with the separate perch is that you lose all that space for travel. and as you know from the "upgrade" from NA to NB top mounts, that top mounting space is valuable.

the picture shown above puts your bumpstop very low. that removes travel. you'd have to have very short shocks to maximize travel.

I would love to see something like that where the bumpstop was raised up from the spring perch so that the shock could compress further. problem is, there's not much space to do it. kind of like the the JIC FLT-TAR rears.



but of course with separate spring perches that move with the spring instead of hard mounted.
Old 01-21-2009 | 07:36 PM
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My issue with the seperate perch is that now ALL the (sprung) weight of the car is supported by the spherical bushing and the mount assembly.

I'm not sure what those bearings are rated for, and I'm sure they make sturdy ones, but just something to think about. In stock setup the sprung weight is transferred straight to the chassis, all compression. With this setup you are hanging all of that weight from the tops of the mounts, all tension forces. Where this mount usually only sees damping forces, you are now adding the mass of the vehicle, and the stored energy of the springs, as well as all of those vibrations.

Maybe it's really not a big deal...but I feel like you're adding a failure point for minimal gain.
Old 01-21-2009 | 08:16 PM
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The bearings aren't a problem, you can get 5000 pound rated thrust load spherical bearings without blinking. The big thing is how much additional travel would make it attractive, and how many people care about a true joint at the shock tower.
Old 01-21-2009 | 08:22 PM
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Ok, now that's a rating!

I was also alluding to the mount structure. Aluminum in this case. Anyone done fatigue life calculations on those for the added load?

EDIT: Again, probably not a big deal, but it is a dill until you've checked.
Old 01-21-2009 | 09:06 PM
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I'll use Mil-spec SN curves to check the number of fatigue cycles to failure for the maximum stress point. You don't have to worry about your part failing.
Old 01-21-2009 | 09:17 PM
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id be interested in something like this for the right price as well..
Old 01-21-2009 | 09:46 PM
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Well whats the right price? What is this worth? Spit it out I gotta know to start.
Old 01-21-2009 | 10:13 PM
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mounts that allow for a little more rear travel (as seen in JIC's above) would be super duper.
Old 01-21-2009 | 10:18 PM
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didnt danscreations make something for the rear a few months back?

Edit: Found it:
https://www.miataturbo.net/forum/t18502/

Looks like its only for tein users
Old 01-21-2009 | 10:26 PM
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Good catch, what happened to this guy?? Looks like the idea wasn't well received back then.
Old 01-21-2009 | 10:31 PM
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they were the expensive...

I know these are $40 each:

Old 01-21-2009 | 10:31 PM
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Originally Posted by thesnowboarder
didnt danscreations make something for the rear a few months back?

Edit: Found it:
https://www.miataturbo.net/forum/t18502/

Looks like its only for tein users
and doesn't use a spherical bearing
and doesn't use a separate spring perch that moves with the shock

I'm gonna post a pic of the FM mounts just to keep the thread complete



note the nice cavity for the bump stop. just slice off some of that phat bottom part and replace it with a shaft-mounted perch... tada.



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