3/4" adapters not strong enough?

[WS6]

So I am about to pull the trigger on adapters for my TA. I'm putting BMW M-parallels on the car. I can run a 3/4" spacer on all four corners. I have gotten quotes from a couple companies for 3/4" adapters. However, I have had one company tell me 3/4" isn't enough meat around the studs. That's the studs that are in the adapter. My question is how is 3/4" not enough? Yeah, it's billet aluminum instead of steel but the axle flange on the rear of my car is no where near 3/4". I believe the thickness of the front Kore3 hubs is right around 1inch at the studs. With what I know and understand 3/4" is plenty. However, I'm not arrogant enough to believe I know everything. So can someone explain to me how 3/4" could not be enough?

Thanks

[FirstGenZq8]

do the m parallels have lug nut "pockets" on the backside of the wheel; ie "deadspace" that the nuts you'll use on the adapters can fit into? see below pic for clarification. i'd measure those pockets to figure out what kind of clearance you'll have, and use that information to reassure the companies you're working with.

https://static1.pt-content.com/images/noimg.gif

[WS6]

Yes there are holes for the adapter lug nuts. That's not the area of concern to this one company. They are saying the lugs that are in the adapter and that the wheel bolts to does not have enough meat to prevent the lugs from being pulled out.

[Mr.VENGEANCE]

just make sure you get a set of shanked acorn lug nuts... like gorillas

[86Cutlass383SR]

With a 3/4" adapter, most companies use the cone style lug nuts to secure the adapter to the hub. The cone makes the 3/4" adapter approz .5" thick in the cone area. Also, since the nut is about 3/4" thick, that's why the wheel needs the extra space for the nuts to fit into.

The shank style doesn't need the reduced thickness but needs more area in the wheel for the nut. The cone type centers the adapter to the hub so some companies say the hub centric ring isn't needed. With the shank style, the ring is needed to center the wheel since the shank doesn't center the adapter to the hub.

3/4" should be enough for the studs that secure the wheels but I'm no engineer either. The lug nut area on some alum wheels aren't much more than .75" so I'd think it would be okay.

[WS6]

Thanks Doug. I think I'll be ok as well. Everything is being machined to be centric tot he axle and hub as well as the wheels. I'll have ARP studs on everything also. My thoughts were like yours, 3/4" is what the wheels and hubs are so why would they not work for the spacers.

I'll post pics in my project thread when I get the adapters. They are coming from Cali and if I order today, I should see them in 1.5 to 2 weeks.

[monteboy84]

Who are you ordering the adaptors through?

I got mine through http://www.motorsport-tech.com/ and am quite happy with them.

On the thickness, there is no reason you can't run a little longer stud and have them use a shorter counterbore, so that the stud is pulling against a 1/2" thickness of aluminum, mine are 1.5" thick and I'm pretty sure the studs holes are thinner than 1/2".....

[WS6]

That's who I was going to use. I need to ask them if they'll thread the holes for me to run 1/2" threaded ARP studs. If not, press in is fine as well.