Teh E36 M3
Teh E36 M3 SuperDork
11/11/20 11:46 a.m.

Ok- weird topic, but big news, I found a '62 MG Midget shell after a 6 year hiatus from my previous project (69 Midget with 4age blacktop power and miata independent rear/front spindles). 

Sussing out drivetrain options, and especially suspensions- would like to piece something together that I have a fighting chance of getting working well. Noted the 2016+ miata front spindles appear to be aluminum. They also appear to have a removable hub/bearing, which also appears to be compatible with the rear hub/bearing. 

The rear hub on those has a five link designed by a masochist that I will not be able to replicate under my MG. BUT, it appears that I might be able to put a rear hub/bearing into a front spindle so I can plug a drive axle in- have upper and lower BALLjoints, and a steering arm to correct toe through the suspension travel.  Planning a double a-arm setup.

 

SO- anyone have any knowledge of my assumptions: 

-2016+ miata spindle is both aluminum AND somewhat lightweight? 

-Hubs are compatible front to rear? 

 

2016-2019 Mazda Miata MX-5 Front Driver Left Spindle Hub Knuckle OEM 16-19 | eBay

2016-2019 Mazda Miata MX-5 Rear Right Spindle Hub Passenger OEM 16-19 | eBay

matthewmcl (Forum Supporter)
matthewmcl (Forum Supporter) Reader
11/11/20 12:24 p.m.

I am very interested in this, but I do not have directly applicable answers.

I will say that if this does not work, you can run Saab 900 knuckles with a FMV rear wheel bearing (2013 escape works, I think I used) and either a VW A2/A3 hub or perhaps also a Miata NA/NB hub. I have not tried the Miata hub to check clearances, but the length and diameter look fine. I can measure/check if you need.

Best brake fit for this approach seems to be VW mk1/mk4 rear calipers (aluminum available). I am looking at Wilwood rotors and hats.

For weight comparison, the 900 front knuckle is about 1/2 lb lighter than the steel NB rear knuckle. The VW aluminum caliper is a couple pounds lighter than the NB steel rear caliper.

I am looking at using the later VW caliper (larger dia) on earlier carriers (workable offset), but I have not actually swapped those parts, yet. Parts are on the shelf.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/11/20 12:27 p.m.

Hmm. I've never looked at front/rear interchangeability of the hubs but that unlocks a few interesting ideas if it fits. Keep us up to date.

Teh E36 M3
Teh E36 M3 SuperDork
11/11/20 1:55 p.m.

Also- I've looked for a bit- can't find info on what NC/ND's had LSD and what types- any sources? Especially a spotters guide.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/11/20 2:10 p.m.

ND: Club and GT-S packages, stick shift only. Applies to all years.

NC I don't know all the variations off the top of my head. Sports had them. Not sure about some of the more luxe packages. Again, MT only.

 

All a Torsen variant. Tokico-Fuji or something like that. Basically a slightly preloaded Torsen. You have to be able to peek down the side holes to spot them.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/11/20 7:35 p.m.

General rule: I suspect that Bilsteins and LSDs are almost always found together in MT cars. That's the case with the ND for sure. 

Teh E36 M3
Teh E36 M3 SuperDork
11/11/20 9:57 p.m.

Thanks keith- I'll see what I can find.

 

Fitz
Fitz GRM+ Memberand New Reader
11/12/20 9:08 a.m.

https://forum.miata.net/vb/showthread.php?t=482644 is a decent spotters guide for determining if an NC has a LSD.

Generally Bilsteins and a 6MT are the best tell but it breaks down the luxury packages which can be helpful for internet shopping. Much easier to spot the DSC Disable button/advanced key setup than the color of a shock absorber from an internet picture.

Ian F (Forum Supporter)
Ian F (Forum Supporter) MegaDork
11/12/20 9:12 a.m.
Keith Tanner said:

Hmm. I've never looked at front/rear interchangeability of the hubs but that unlocks a few interesting ideas if it fits. Keep us up to date.

Drat... and here I was assuming/hoping FM would happen to have some ND assemblies sitting on a shelf you could check... wink

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/12/20 9:22 a.m.
Ian F (Forum Supporter) said:
Keith Tanner said:

Hmm. I've never looked at front/rear interchangeability of the hubs but that unlocks a few interesting ideas if it fits. Keep us up to date.

Drat... and here I was assuming/hoping FM would happen to have some ND assemblies sitting on a shelf you could check... wink

All of ours are attached to cars! We haven't scrapped an ND yet.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/12/20 9:24 a.m.
Fitz said:

https://forum.miata.net/vb/showthread.php?t=482644 is a decent spotters guide for determining if an NC has a LSD.

Generally Bilsteins and a 6MT are the best tell but it breaks down the luxury packages which can be helpful for internet shopping. Much easier to spot the DSC Disable button/advanced key setup than the color of a shock absorber from an internet picture.

If we're using internet pictures, just call Mazda with the VIN. I was thinking more junkyard style since we're looking for parts and not a car.

nocones
nocones GRM+ Memberand UltraDork
11/12/20 9:25 a.m.

It looks likely that they are the same.  The wheel bearings are not the same part number but I'd imagine that is because the hub itself is different (not broached for splines on the front).  I'd imagine the Wheel bearing and tripod carrier are the same.  I mean that's how I'd do it if I was building it.  

That said that 5 link doesn't look to bad to dealwith.  Just use only 3 of the mounts.  Looks like using the Left 2 in that picture as the bottom, and the right most as the top would make it pretty simple.  The bottom could be an A-arm and a Toe link, the top just an A-arm.  The origninal design of my MG used stock 2nd gen RX-7 uprights which had strange canted bolts like that.  It was fine to deal with.  

The advantage it has is your front/Rear brake relationship is already figured out and your toe-link would be relatively level.  With a front suspension the steering arm is almost never level with the upper or lower ball joint.  In the front suspension getting the bumpsteer as close as possible with a mid point steering link is fine because in your hands you hold a steering wheel and can respond to subtle bumpsteer changes.  In the rear it's less desireable because you can't directly correct for it so it come down to very good design of the links.  That's what makes a 5 link so hard to replicate.   

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/12/20 9:55 a.m.

nocones, where did you find a listing for a separate bearing? Mazda lists only the hub. Of course they're different because of the hole.

I'm going to get someone to do a quick eyeball/measurement of a car because the possibilities this brings up are just so yummy.

Note that the ND has some dynamic toe changes in the rear that come from different bushing durometers. It could take a bit of trial and error to dial in the handling if you don't do an exact copy of what's already there. Moving a non-steering steering link up and down to zero out bumpsteer wouldn't be too difficult.

nocones
nocones GRM+ Memberand UltraDork
11/12/20 10:40 a.m.

In reply to Keith Tanner :

I meant the thing you can buy from Mazda that is a "Wheel bearing" which is the bolt on tripod hub assembly.  

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
11/12/20 1:05 p.m.

FYI, Kyle took a look: 

"They do not use the same pattern. The rear looks to be a true equilateral where as the front has one short side."

Teh E36 M3
Teh E36 M3 SuperDork
11/12/20 2:41 p.m.

F. Thank you. 

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