I just finished mini-tubbing my future street/strip 64 fairlane, and I need to order some axles/wheels/tires to finish out my rear axle. I have been trying to read my NHRA rule book, but I am a little confused. I am trying to build the car to pass tech for 7.99 and slower, and need to know what I need for wheel studs. Can I run standard lugs with closed lug nuts as long as I have at least as much thread engagement as the lug diameter? Do I need 3" long drag studs and open lug nuts? When do you need 5/8 studs?
If it were me I would upgrade just to be on the safe side, larger and longer with open threads, it sucks when you twist lugnuts off doing burnouts..........just don't ask me how I know
Txag01, The answer to part of your question is: you have to have open lug nuts with thread sticking out. I don't know about size though. This is certainly a case where bigger is better. I am at the same stage of building my gasser and need to order rear axles. I'd rather over build now than rebuild it later. Try not to skimp, at least when possible. Best luck on your build, Normal Norman
the nhra rule says you need one diameter's worth of thread engagement in the hex part of the nut. Which basically means you need open ended nuts, and the studs have to poke out the ends of the nuts. some tracks have weird translations of this that say you need one diameter's worth of threads poking out PAST the nut, which is not what NHRA requires I think NHRA requires this on all cars, but some tracks let cars with street tires run without meeting the rule
The way I read it, 1 to 1 thread engagement would be 1/2" in the hex for 1/2" stud. That wouldn't necessarily put the end of the lugs through the lugnut and capped nuts might work. The rulebook I grabbed was an older one (200*) and it didn't say anything about open ended lugnuts. But do you wanna have to pull a lugnut everytime you go race to get them checked? I've always run open ended nuts with the lug sticking through at least a couple of threads. If a littles good, mores better,................ You can't over build this stuff. Larry T BTW NHRA Tech has an e-mail address you can send questions too. I've had real good luck using it. And if there is any questions about your legality after you've talked to them and you have saved e-mails to fall back on it sure could save some hassles.
If you are getting aftermarket axles then get them cut for 1/2" thread. The length depends on which wheel you use, 2 or 3" long are available. The 5/8 drive stud is when you have a little more hp. You need to know how thick your wheel will be to order the stud, if you don't know then go with the 3" like most of the people and sometimes you'll have more then necessary sticking out. Order the studs from your axle guy.
Notice how you cant see the wheel studs even with the open-ended lug nuts? The studs on this car didnt protrude even into the hex portion of the nut. A tech inspector would just laugh and direct you to the exit gate. This might seem obvious, but make sure all the lug nuts are on each wheel, and that theyre tight. On fast cars and cars with aftermarket wheels, the inspectors will check to make sure the nut is grabbing enough of the stud. The rulebook says that the wheel stud must protrude into the hex portion of the nut a distance that is at least equal to the diameter of the stud. Get extra-long studs and use open-ended nuts and youll never have a problem. Hope this helps... Desert
If you're buying aftermarket axles and such, call the company and explain to the tech person what you need/want to do. I remember one of the first vehicles down the track last year at the Winternationals was a Dodge truck. He ended up shearing off the rear studs and taking out the Christmas tree.
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