Hubcentric vs. Lugcentric Stuff

[f2fast4u]

The popular theory of 03 Cobra owners is that you can't run wheel spacers that aren't hubcentric due to the excessive stress placed on the wheel studs. Some people report horror stories of their studs breaking off while driving (re-torqued ever?).

That being said, many Fox owners run North Cobra rear disc brackets (or similar) using Ranger rear axles and Lincoln front hubs (lugcentric) and yet use hubcentric wheels (Cobra R's, 03 Cobra's, Bullits, etc.) with no problems at all. That are a ton of those cars out there with lots of horsepower having no problems at all.

FWIW, the machined hub on lugcentric axles is smaller in diameter than the machined hub on hubcentric axles. So, a hubcentric wheel when installed on a lugcentric axle will not touch the machined hub on the axle. Plus, the stud hole diameter on Cobra R rims and Mach 1 rims are identical in measurement... I just measured them. And yes, both sets use studs that are 1/2" diameter with 20 threads per inch.

Seems to me that the studs in the 93 and older Mustangs are stronger than 94 and up studs. I have personally snapped the stud on a new Mach 1 using only a 1/2" craftsman rachet and my arms. Older vehilces would require a cheater bar to have enough power to do that.

So, my thoughts are that the weak link is the newer studs. That is my theory. Any one have thoughts on this? And yes, I own examples (multiple) of each.

Anyone else think it's the studs?

 

[f2fast4u]

Comments? - seen lots on this subject, but none addressed the studs.

 

[stangfan]

I ran a 1/4" spacer on my Cobra for appx. 10K miles with 468 lb/ft of TQ with no problem what so ever. Drove her down the drag strip at least 20 times, had numerous hard launches on the street, and did plenty of burnouts with the stock f1's... without issue:shrug:

 

[f2fast4u]

stangfan - what type of spacers are you using? Who makes them?

 

[stangfan]

Not sure? They were 'hand-me-downs' from my buddy's 94 cobra (410 RWHP)... I took them off when I put on the 18" R's. I gave them back.

I can find out if you want? Just let me know.

 

[f2fast4u]

Probably not hubcentric. Those are speciality items made by some machine shops. Thanks for the reply. I still think the weak link is those studs and owners not checking the torquing on a regular basis.

 

[cito]

Hubcentric spacers just reduce the chance for lug shear. This is supposed to be because the hubcentric spacers essentially become part of the hub. There is no shear plane per se.

Don't know about the lug question. Hubcentric spacers are simply the safer way to go.

 

[f2fast4u]

cito- I agree with what you're saying but only because the strength of the studs has changed. That is what I think. Again, why else could older cars run newer rims with no problems? It's the same example. And given that I believe changing to stronger studs would be safer than paying for expensive hubcentric spacers. That's why I'm changing to all ARP 100-7707 studs and not worrying about the spacers.