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Posted by: ! Jan 1 2004, 11:12 PM

I have a rubbing on the inside wheel wells due to a chassis stiffening kit. I need to space out the wheel to lower the rear and try and get some more negative camber....what is the minimum number of turns that a lug nut have to be safe and/or legal for DE or AX?

I can always add longer studs but I would like to avoid the labor if I don't have to....or should I just use open top nuts and see if the studs pass the top of the nut when fully tightened?

Posted by: Gint Jan 1 2004, 11:21 PM

There is actually a spec (SAE?) for fasteners regarding the amount of thread engagement of a nut on a bolt. I don't remember what it is. I think I heard soemthing about this from Geoff at one time or another.

After thinking about it, it might have been Sammy.

Posted by: J P Stein Jan 1 2004, 11:22 PM

I use the 7mm spacers and put on steel lug nuts....IMO, the stock stud ain't doing the trick. I get about 6 turns, 9 would be better or one thread past the nut, better still.
I'm getting longer studs.

Posted by: SirAndy Jan 1 2004, 11:41 PM

somehow, the number 7 comes to mind ....

where's brad when you need him?
Andy

Posted by: Gint Jan 1 2004, 11:45 PM

It's starting to come back to me. I vaguely recall a measurement. Something like the bolt should actually engage all of threads on the nut, plus an additional 1/3 of the thickness of the total threads on the nut.

But what do I know.

Posted by: Carrera916 Jan 1 2004, 11:46 PM

I would have to agree with JP as from my experience watching & working on race cars, we always put a longer stud on with the idea of at least a thread or two sticking out of the nut. You would want the full clamping force on the wheel expecially if you're gonna drive her hard around the corner....

j

Posted by: Brad Roberts Jan 2 2004, 12:48 AM

This is from PCA:

"Wheel bolt/lug nut engagement must be at least one times the bolt/stud diameter." This is nine turns on a Porsche set-up.

NHRA is different.. (burnout Z)


B

Posted by: ArtechnikA Jan 2 2004, 06:30 AM

the Zone 8 spec used to be "end of the stud and tight". my roadwheels barely meet this spec with stock studs and no spacers (fat cast pseudoFuchs). i suppose i could have 0,1" milled off the lug nuts to make them legal, but somehow i don't think that's what they meant...

i can send you a spare steel lug nut if you want, but i have to believe you have a source closer than me ...

i believe the generic thread engagement spec is 1.5 x the diameter of the stud.

just bite the bullet and install 100mm studs with NASCAR ends ...