Hello All,
I have been spending some time playing with na/nb spindles and hubs making plans to adapt the spindle to my Pinto. There are a few advantages to the Miata spindle in my application, but that's not what I want to discuss here. My question is this:
With the amount of front hub/wheel bearing failures reported online, is it a bad choice at this point to use Miata front spindles for a build that will see track time? From what I gather mustang ii style hub/rotors are heavier but also stronger. I'm interested to hear peoples thoughts on the topic.
There are a lot of hub failures being reported because there are a very large number of Miatas on track, and the newest NB Miata is now 18 years old. But yeah, it's a weak point.
Because it's a weak point, it's also been addressed by the aftermarket. There are at least four upgrade options I can think of - maybe five. They range from ones direct from Mazda Motorsports to high-dollar roller bearings to modified E30 parts.
What's your wheel plan for front and rear? I'd take bolt pattern as a requirement in your choice, because that's a pain to change. 4x100 (Miata) may not have the wheel selection you get with the Mustang (5x4.5?).
In reply to Keith Tanner :
I have 4x100 in the rear now (Miata spindles) and currently run 5x4.5 in the front (mustang ii rotors), so lug pattern isn't a huge concern (circle track wheels). I like everything about the current setup except the brake caliper/pad options. The Miata hub/rotor/bearing is within a pound of the mustang ii parts, and is .75" larger in diameter. Also there are much better pad options for the Miata calipers than the early pinto calipers (71-73).
So my options are adapt a better caliper to my early Pinto spindles, or move to Miata spindles for the brake options. Both spindles can be upgraded in the aftermarket, but I am trying to avoid options that are too spendy.
I would honestly go with a Miata spindles over the Mustang 2 purely for bolt on hubs. That and the off-the-shelf big brake kits make it a no-brainer for me. I wouldn't worry too much about Hub failures at this point, as you're only doing occasional track days and not with race rubber. That is just my opinion and worth exactly what you paid for it.
Yeah, for occasional fun time it's not worth getting too worried about it. Spec Miata racers on Hoosiers and 25 hour enduro racers are a totally different breed from that. Get some blueprinted hubs, torque them properly and enjoy. IIRC the last year I ran T25 we did the blueprinted hub route and didn't lose a front hub across 4 cars. The year before that, we were running "whatever was on the car" and had all sorts of trouble.
No personal experience with the E30 upgrade but it looks promising as well.
Keith Tanner said:
Yeah, for occasional fun time it's not worth getting too worried about it. Spec Miata racers on Hoosiers and 25 hour enduro racers are a totally different breed from that. Get some blueprinted hubs, torque them properly and enjoy. IIRC the last year I ran T25 we did the blueprinted hub route and didn't lose a front hub across 4 cars. The year before that, we were running "whatever was on the car" and had all sorts of trouble.
Yes, there's a big difference between the hubs you'll get from RockAuto or Autozone and the "blueprinted" style hubs from Mazda Motorsports or Flyin' Miata. This is both in the quality of the ball bearings and grease but also in the quaity of the hub casting itself. I've had really good luck with the Flyin' Miata blueprinted hubs on my track day Miata (205mm 200TW tires). IMO most track Miatas don't need to go all the way to the really fancy aftermarket hubs. Of course, when building a car the "buy once, cry once" strategy can be a good one.
Dusterbd13-michael said:
I would honestly go with a Miata spindles over the Mustang 2 purely for bolt on hubs. That and the off-the-shelf big brake kits make it a no-brainer for me. I wouldn't worry too much about Hub failures at this point, as you're only doing occasional track days and not with race rubber. That is just my opinion and worth exactly what you paid for it.
Just for clarification, the OP was talking about NA and NB Miata hubs, which are are spindle type, not bolt on. The NC Miata had bolt on front hubs. Also, the NA and NB Miata have the 4X100 wheel bolt patern, while the NC has the 5X114.3 (5X4.5") bolt pattern.
In reply to mainlandboy :
Well....
The Miata hubs bolt to the spindle, so the inner and outer races end up becoming structural as far as spindle bending loads are concerned - the spindle would have to stretch in order to bend or even flex, because of that super tight nut holding it together.
Tapered bearing setups like the Pinto have are basically just a loose collection of parts riding on the spindle, which can bend/flex more easily as a result, unless you have some of those spiffy bearing spacers like a rearend has between its pinion bearings. Then you can reef the nut down tight and the races become structural. But those are fiddly and the preload may have to be reset every time you change a brake rotor, whereas with the Miata setup you just remove the nut, chuck the old part, install new, tighten nut, and away you go.
terminology ident - the "upright" (or "knuckle" if you prefer) is the whole mess between the upper and lower ball joints, the "spindle" is just the sticky-outy bit on the upright that the hub slides onto.
Old RX-7 and pre RX-7 racers have a lot of issues with the spindles bending or even breaking, they have tapered bearings and everything can flop around as a result. I have not heard of spindles separating from uprights on Miatas, even though Miata spindles are smaller at the base.
In reply to Pete. (l33t FS) :
My assumption was that the comment made about the benefit of the "bolt on hubs" was in reference to the cartridge style used on the NC Miata, which bolts to the knuckle:
...as opposed to the style that slides on the spindle, as used on the NA and NB Miata:
Well, accuracy wasn't my strong suit. Maybe i should have said unitized instead of bolt on. But pete explained what i was going for way better than i can.
Either hub design is superior to what the mustand2 stuff is.
How much does the car weigh? What size and what kind of tire are you putting on it? And does "some track time" mean you're going to do a couple casual TNIA-style events per year, or are you chasing class wins in a competitive Time Trial series?
