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Discussion Starter #101
more importantly, without an OEM part, in the box, there's no comparison to stock to be made, and an SCCA protest will crumple like tissue paper. get it close and call it done.
OMG! Chip?! :toast

Back from Glorious Daytona, back to freakin freezing DC. UGH!

Will be shipping said hub sample to Matrix today.

:thumbup
 

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I had a long discussion about this over the weekend and can't remember if the following theory has been discussed in this thread or not (and I'm too lazy to read through it again to check).

We were trying to figure out why some drivers have had hub failures and others not. We ruled out the amount of negative camber as we didn't think there would be that much added stress between say -2 and -4 degrees.

We ruled out how hard the drivers are going through the turns as I know of some fast drivers who have had none. Bill Griffith goes as hard or harder through the turns than me and I've broken 2 front hubs and he has had no failures.

We then discussed a theory that Bill first brought up to me. Bill's rims mate up to the rotor the full 360 degrees around the rim. My rims have 4 "pads" spaced evenly around the rim. Only these "pads" actually mate up to the rotor. The pads probably amount to about 1/2 of the circumference (maybe less) around the rim (at the studs). I didn't see how this could effect the hub as the rotor is sandwiched between the hub and the rim and would therefore transfer the load evenly to the hub. However the guy I was discussing this with pointed out that those contact pads were acting as heat sinks and as a result the rotor would heat up and cool down unevenly. The difference in temperature could cause warpage in the rotor and as a result additional flex in the hub.

Does anyone think there is any merit to this theory? Of those who have had hub failures, have any of you been running rims that mate up to the rotor all the way around the rim?
 

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Just like your theory of force transfer the rotor and hub will also spread out the heat transfer. I doubt the heat would be noticeably less even on your setup. It would transfer less heat though. It may be possible the rotor and hub gets hotter altogether. Metal conducts heat many times better than air.
Even though the rotor should help greatly to even out the load on the hub I am still open to the possibility it may not be as even as the full contact wheel. I would be interested to hear if anyone else is running either setup that supports or dismisses the theory.
 

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Steve - what's the ratio of failed hubs with and without hubcentric wheels or rings? the small out of round condition typical of non hubcentric wheel mounts might not be noticeable to you, but the constant oscillation at the hub COULD be another potential contributor to failure.

and yes, AJ, it's me. I have ~ 40 posts on this board in the past 4 years. it's not like I'm a stranger... ;)
 

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Discussion Starter #105
and yes, AJ, it's me. I have ~ 40 posts on this board in the past 4 years. it's not like I'm a stranger... ;)
I was refering to your position on hub replacement, my friend!

:smile:
 

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If you want to collect statistical data on the configurations that do/don't break hubs; you have to cover everything.

Beckley ITB (former Doane ITA) MKI:

Circumferential cracking where the rotor-wheel flange meets the center bore hub, YES
Qty of failures with just circumferential cracking, 1 (Doane), TBD (Beckley)
Circumferential cracking and radial cracking (thru the access holes),YES
Qty of failures with both circumferential and radial cracking, 1 (Doane), TBD (Beckley)
Qty of failures with complete separation of flange and center bore hub, 1 (Doane), TBD (Beckley)
Associated Wheel bearing failure, NO
New wheel bearing installed as delivered, YES
New wheel bearing re-greased before installation, NO
Dust Cap grease fitting added, NO
Signs of overheating, NO
Street Tire, NO
Street Tire size, NA
DOT Slick Tire, YES
DOT Slick tire size, 205/45
Bias Belted Slick Tire, NO
Bias Belted Slick tires size, NA
OEM/Lug Centric wheels for dry tires, NO
OEM/Lug Centric wheel size, NA
Hub Centric wheels for dry tires, YES
Hub Centric wheel size, 14X6 and 14X7 (Doane)
Full Contact wheel mounting surface, (??? Steve needs to answer this)
Non-Full Contact wheel mounting surface, (??? Steve needs to answer this)
Front Wheel spacers for dry tires, YES
Front Wheel spacer thickness, TBD
Extended-long lugs, YES
Brake Dust Shields installed, NO
Brake Ducts installed, NO
Normal Front camber setting, -2.5deg (Doane)
Normal Front toe setting, 1/32" Out (Doane)
Normal Front Caster setting, TBD
 

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you left some things off.

wheel offset
wheel spacer thickness
*resultant wheel offset (offset-spacer=X)
hubcentic spacer or hubcentricity maintained with spacer?
wheel weight
hub age (in race time / miles)
brake pad type (relevant for operating temps, assumedly >1000°F intermittent)
etc...

there's a LOT that could contribute. could just be random porous casting, too - though I hope not. do you have good pics of a hub failure to rule that out?
 

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Discussion Starter #109
Maybe it's just T6A at Summit Point!
You guys are making my head hurt.

Just make it stonger, DAMMIT! :smile:
 

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Okay so I sent the hub out to the driveshaft shop and this is their reply.

ok the front hub would have to made from 4340 billet, i can make them but the cost may be prohibitive. they would run
about 500.00 and i would have to make at least 20 of them to make it worth the engineering and set up time.
 

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Discussion Starter #111 (Edited)
Kinda what I was expecting, but thanks for trying.
 

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Kinda what I was expecting, but thanks for trying.
Sounds like you are giving up.
Is it the quantity or the price?
The price seems pretty reasonable for a custom hub that should last for ever.

If it's the quantity, it may not be impossible.
If a few people here would be willing to get the ball rolling and say they will buy a set and if people put the word out on racing boards, and international boards, I could put some posts on the boards I am on and the Facebook groups I am on. Seems like on an international level it may not be impossible to find 10 people who race their cars hard enough to want these.
 

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wait a minute...I just caught this part. Has everyone who had a failure been using wheel spacers?
I don't think most if any have but I haven't read the whole thread all the way through.
Too much offset can have the same effect too though. It's a valid part of the equation for sure.
 

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Okay so I sent the hub out to the driveshaft shop and this is their reply.



Quote:

ok the front hub would have to made from 4340 billet, i can make them but the cost may be prohibitive. they would run
about 500.00 and i would have to make at least 20 of them to make it worth the engineering and set up time.


$500 does not sound to bad but 20 sets that could be a problem

I'm in if you want to take a head count

question are they any other front hubs that would work like a AE92 or a
GT4?

Davegt27
 

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the problem with E90, P80, etc... series hubs, is the hole through the middle of the hub. there's no way to pull all of the elements together like the spindle and nut style piece on the front of the AW11.

you could take an AE92 front hub and cut down a CV joint end to be just a spindle with a nail head so that it passes through the bearings and probably wind up with a usable assembly (not sure about spacing, but the bearing PN is the same), but it would not be IT compliant, not even close.
 

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thanks Mike. the Miata guys have certainly done a lot of work finding optimal wheel bearing greases and manufacturers. one of the benefits of a well subscribed spec class. FYI - the grease they are using APPEARS to be NEO HP800 based on color. it's really good stuff.
 

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MK1 Hubs

Guys I have developed an alternative to the stock front hub but requires a change to the 4X100 bolt pattern thereby necessitating wheels with a different bolt pattern. This bolt pattern would probably not be legal for IT but should be legal for production, GT, or ST. Further, the IT rules is why I have decided to run STL instead. These hubs are std Toyota pieces with minor machining but are a lot stronger.
 

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Rudy, you might want to check the alt hub allowances of STL. I'm pretty sure they have to be stock-for-the-car pieces there, too. I could be, and hopefully am, wrong.

either way, 4x100 hubs are all over the place that WILL work with some additions, and the idea of custom machined hubs is valid too, if you want to incur the expense. Those will fly farther under the radar than a bolt pattern change.
 
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