Gauge

iTrader: (3)

Hey guys,

What are the NHRA rules on wheel studs? I broke one of my stockers, and I figure that I'll just upgrade to something that will pass tech. I've read around and haven't found a definite answer. What I've read implies that it's not a certain length that's legal but a certain distance that the studs have to stick out beyond your wheels. Can anyone enlighten me?


Thanks!

JRcamaroZ28

iTrader: (41)

the stud has to enter the hex portion of the lug as far as its thickness of the stud not counting the washer (ie. if you have a 1/2" stud it has to enter the lug 1/2" or more)

JL ws-6

iTrader: (50)

It was my understanding they have to stick out of the lug nut an equeal amount as the diameter of the stud... if you go with stock dia. studs, just get theh 3.25 lenth, you will have to run openended lug nuts with your street wheels from now on, but it's notthat big a deal. They will stick out of the stock rims some, but it doesn't look that bad IMO

Fire67

iTrader: (3)

JRcamaroZ28 is 100% correct. They do not have to protrude at all.

JL ws-6

iTrader: (50)

well then I guess I'm over safe, mine all stick out the dia. of the lugnut or more.

RUQWIKR

iTrader: (11)

For inspection purposes, if they don't protude, I'd still recommend open-ended lugs so the Tech guys can see. Also, on a kind-of-related subject, your wheels all need screw-in valve stems, not rubber press-in. Take care. Dave

Gauge

iTrader: (3)

Thanks, RUQWIKR. I saw you out at Redline on Saturday. DAMN, your car is fast.

brandonppr

iTrader: (9)

I think they want to be able to see them for inspection for one reason to make sure they are all tight. if the lugs had caps on them you could not tell if its tight or not.

Why do you have to change the valve stem to screw in? do the screw in type leak? can they be used on stock wheels?

Fire67

iTrader: (3)

Not so much screw-in as they are screw/bolt together. They dont leak if installed properly as they have a rubber backed sealing washer or two to seal against one or both sides of the wheel.

The reason is because the rubber ones fail. Ive had more than a few actually rip open from the centrifical force.

I thought that was a given, Ive run the bolt-on stems forever. Started using them after a high speed interstate blast left me on the shoulder of an off-ramp with a flat tire. The damn rubber valve stem had ripped right at the base and let the air out.

brandonppr

iTrader: (9)

thanks now I understand. I found this pic for reference:


BTW I put longer studs on my car after my stockers sheared off one day and I didn't have to have new lug nuts I just had to screw the chrome ones I had on and the cap just pops off. its just a thin metal cap anyway.
not the best pic but here it is: (only 3 lug nuts installed)

RUQWIKR

iTrader: (11)

Just let me know if you have anymore questions. The car is fully certified (NHRA) and legal, so, I should be able to answer all / most of your questions.

I'm out there about once per month...next time probably 6/9...when you drop by, let me know your handle on LS1Tech to put a face to a "name"...

Take care. Dave

PS: Got a good signature pic at Redline on Saturday (Thanks to RNBob!)

z-ya

iTrader: (1)

ya I was a tech inspector,they just have to stick into the hex portion of the lug nut
at least the diameter of said axel stud.

SJM Manufacturing Inc

iTrader: (5)

Just for a bit of clarification, the THREADED portion of the stud needs to enter into the hex portion as described above, not just the stud shoulder. Some bolts i.e. ARP have a very large shoulder up to .5" long which is not threaded. Granted, you'd probably still pass tech at most races, but it is not safe.

Threads need to enter into the hex portion due to the fact that when the bolt is under tension, the hex portion needs supported. When the stud is under tension with the lug (tensile stress), it can sheer at the shank area if the stud's threaded portion is not into the hex head (the hex portion of the lug-nut is actually what is holding the wheel on the car). The high-stress area will be right where the hex portion of the lug nut tapers to the shank.