Spherical bearings
08-04-2015, 03:11 PM
#21
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Sharky, you need to have your friend measure those sphericals and then buy the same size from NHBB. NHBB sells the only sphericals with actual thrust load testing done on them, aurora only gives you a rule of thumb based on the radial load rating, NHBB gives you an axial load rating on some of them.
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08-05-2015, 11:43 PM
#23
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https://en.wikipedia.org/wiki/Ford_Fox_platform#SN-95
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08-06-2015, 12:17 AM
#24
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As someone with a background in design and manufacturing, I still fail to comprehend the desire to share a common "platform" across vehicles with differing wheelbases and drivetrain configurations.
Different presses, different jigs, different molds... Where exactly is the commonality?
Different presses, different jigs, different molds... Where exactly is the commonality?
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08-06-2015, 12:29 AM
#25
As someone with a background in design and manufacturing, I still fail to comprehend the desire to share a common "platform" across vehicles with differing wheelbases and drivetrain configurations.
Different presses, different jigs, different molds... Where exactly is the commonality?
Different presses, different jigs, different molds... Where exactly is the commonality?
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08-06-2015, 12:40 AM
#26
I will say that the upper hat and spherical bearing made a very noticeable difference. We did only that mod at that time and without proper alignment (aka put it in a drove around) it made the steering far more precise. The 2000 Mustangs are built more like trucks. Like trucks with fail struts and fail 4 link rear.
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08-06-2015, 12:50 AM
#27
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That's one thing Mazda did right on the NA. Threw it together out of discarded bits of other cars, but without deluding themselves into thinking that it'd be a good idea to start the chassis design by laying a sheet of translucency over the old F or H blueprints.
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08-06-2015, 01:49 AM
#28
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It sounds good in theory, but I've participated in that mass hallucination on several projects. You wind up spending way more time in design revision and document control than if you'd just started with a clean sheet and a parts bin.
That's one thing Mazda did right on the NA. Threw it together out of discarded bits of other cars, but without deluding themselves into thinking that it'd be a good idea to start the chassis design by laying a sheet of translucency over the old F or H blueprints.
That's one thing Mazda did right on the NA. Threw it together out of discarded bits of other cars, but without deluding themselves into thinking that it'd be a good idea to start the chassis design by laying a sheet of translucency over the old F or H blueprints.
The NA may be a clean-sheet, but the NB is barely changed at all from the NA, and the NC shared a lot of parts with the Rx-8. Dunno about the ND.
I suspect that platform sharing makes more sense for more "normal" cars, where you just want to crank about a few different sedans of different sizes and luxury levels in order to appeal to more buyers. Trying to apply it to sports cars leads to things like the 350Z weighing 400 pounds more than it really ought to have.
--Ian
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08-06-2015, 04:27 PM
#30
Perhaps. I'm a software guy, and if we threw out the source code and started over every time we built a new router, we wouldn't get very far.
The NA may be a clean-sheet, but the NB is barely changed at all from the NA, and the NC shared a lot of parts with the Rx-8. Dunno about the ND.
I suspect that platform sharing makes more sense for more "normal" cars, where you just want to crank about a few different sedans of different sizes and luxury levels in order to appeal to more buyers. Trying to apply it to sports cars leads to things like the 350Z weighing 400 pounds more than it really ought to have.
--Ian
The NA may be a clean-sheet, but the NB is barely changed at all from the NA, and the NC shared a lot of parts with the Rx-8. Dunno about the ND.
I suspect that platform sharing makes more sense for more "normal" cars, where you just want to crank about a few different sedans of different sizes and luxury levels in order to appeal to more buyers. Trying to apply it to sports cars leads to things like the 350Z weighing 400 pounds more than it really ought to have.
--Ian
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08-06-2015, 10:11 PM
#31
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I agree with leafy, they're pretty far down on my list of things that will make a difference on the miata setup. Honestly the better value would be in the rod eye solution up thread. At least that gets you access to lots of good motorsports shocks.
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08-10-2015, 09:25 PM
#34
Bearings, effectively, don't have hysteresis that rubber bushings have. This eliminates a lot of undamped movement in the coilover.
Beyond that undamped movement, the rubber bushings bind and have their own spring rate. As the damper is compressed, the lower half travels through a shallow arc while the top is constrained. This swinging back and forth acts on the coil spring, leveraged against the shock seals. This lateral and twisting force adds a lot of seal drag and not in a linear curve.
Most "pillow ball" mounts just replace the rubber bushing with a bearing. Unfortunately, the greatest tangential loads imparted on the shock shaft are from the spring acting on the body mount off axis. That generate a lateral thrust load. Some higher end coilovers will have a separate, semi isolated "coaxial" upper perch just for the spring that is allowed to swing independent of the body mount. This coaxial perch mount is the inspiration for all the JDM style coilovers with "pillow ball" mounts but without the actual coaxial perch function. The coaxial perches takes up a few mm of space that has to be allowed for in the layout of the coilover to insure the correct bump/droop travel and stroke.
In a nutshell, it's friction we're reducing or eliminating by replacing bushings with bearings.
Teaser of the new SuperMiata coaxial billet mounts we just put into production. Coming around December (not taking pre-orders). These will be available as an option for Gen 1/2 Xidas for $299 for the set of four. We're adding options for 70mm (Tein) and 2.5" spring perches along with a simple adapter kit so any damper with a NB sized 12mm pin can run them. So Bilsteins, Koni's or whatever else you have.
We also reshaped them a bit for tire clearance. These are much narrower than an NB mount but still fully supported on the body.
Beyond that undamped movement, the rubber bushings bind and have their own spring rate. As the damper is compressed, the lower half travels through a shallow arc while the top is constrained. This swinging back and forth acts on the coil spring, leveraged against the shock seals. This lateral and twisting force adds a lot of seal drag and not in a linear curve.
Most "pillow ball" mounts just replace the rubber bushing with a bearing. Unfortunately, the greatest tangential loads imparted on the shock shaft are from the spring acting on the body mount off axis. That generate a lateral thrust load. Some higher end coilovers will have a separate, semi isolated "coaxial" upper perch just for the spring that is allowed to swing independent of the body mount. This coaxial perch mount is the inspiration for all the JDM style coilovers with "pillow ball" mounts but without the actual coaxial perch function. The coaxial perches takes up a few mm of space that has to be allowed for in the layout of the coilover to insure the correct bump/droop travel and stroke.
In a nutshell, it's friction we're reducing or eliminating by replacing bushings with bearings.
Teaser of the new SuperMiata coaxial billet mounts we just put into production. Coming around December (not taking pre-orders). These will be available as an option for Gen 1/2 Xidas for $299 for the set of four. We're adding options for 70mm (Tein) and 2.5" spring perches along with a simple adapter kit so any damper with a NB sized 12mm pin can run them. So Bilsteins, Koni's or whatever else you have.
We also reshaped them a bit for tire clearance. These are much narrower than an NB mount but still fully supported on the body.
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08-10-2015, 10:04 PM
#36
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<p>Thank you for the reasonable pricing (in my eyes) emilio. You're product will be selling for half as much as some others on the market and looks ****.</p>
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08-11-2015, 11:37 AM
#40
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Emilio, do you have any data on change in shock performance? I do believe that they work, I'm just not sure how much of an effect they'll have. They're pretty low on my list (pretty much after replacing every other bushing with sphericals) if I decide to keep my Miata, but I'm open to reconsidering.
How do they take up axial loads. Most spherical bearings either aren't rated for them, or aren't rated for very much. I trust with your name on them they work, I'm just curious.
Also, I think that the JDM style pillow ball mounts reflect the fact that a lot of these go on McPherson struts, where they do actually do something.
How do they take up axial loads. Most spherical bearings either aren't rated for them, or aren't rated for very much. I trust with your name on them they work, I'm just curious.
Also, I think that the JDM style pillow ball mounts reflect the fact that a lot of these go on McPherson struts, where they do actually do something.
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