Thunderhill lap video and broken wheel stud question

[skyline23]

Hi everyone,

was at Thunderhill this past weekend and on my last session somehow broke one of my rear wheel studs off. Not entirely sure how other then maybe the lugnuts worked themselves loose. I normally am religious about checking torque settings after every session but never once have seen them come loose so got lazy didn't do it for two 20 minute sessions in a row, so this is the only thing I can think of.

Does anyone have recommendations on the best way to go about fixing this? Do I have to replace the whole hub, or can I replace just the broken stud? Part numbers and cost estimates and where to buy these parts would be extremely appreciated.

On a related note, below is a link of one of my laps that day using Harry's Laptimer. I know there is lots of room for improvement but I am pleased that everytime I go out there I shave some time off my laptimes and am fairly consistent each day.

http://www.youtube.com/watch?v=v98Dno91Fw8&feature=youtu.be

 

[RSO 34]

I had that happen to me at Lime Rock in the left hander when two adjacent studs broke and the wheel sheared off. As a precaution I replaced all the studs for all four wheels.

<iframe width="560" height="315" src="http://www.youtube.com/embed/fcw8lVlH5_o" frameborder="0" allowfullscreen></iframe>

 

[nsxtasy]

I normally am religious about checking torque settings after every session

I hope you mean checking torque settings before every session, or at least, not immediately after every session. You shouldn't torque the lug nuts when they're hot, right when you come off the track, because the studs can be so hot that they're able to stretch enough that they can't be torqued to the proper setting. I once found this out the hard way.

 

[skyline23]

I hope you mean checking torque settings before every session, or at least, not immediately after every session. You shouldn't torque the lug nuts when they're hot, right when you come off the track, because the studs can be so hot that they're able to stretch enough that they can't be torqued to the proper setting. I once found this out the hard way.

Yes, thats what I meant, good catch. Yea I definitely don't check after each session as I don't want to burn my hands

 

[silver2002]

Enjoyed the video. Sounds like you have a S/C?

Re: Wheel Studs
What year?
Mileage?
HP?

 

[CL65 Captain]

Most importantly.... what wheels? And are you using a centering ring?

Like this....

 

[skyline23]

Enjoyed the video. Sounds like you have a S/C?

Re: Wheel Studs
What year?
Mileage?
HP?

Thanks. Yep, I have one of the early Comptech superchargers with high boost pulley and AEM FIC. Car dynod at around 375 whp. It is a 91 with about 130k miles, however the motor has been rebuilt by Driving Ambition about 3-5k miles ago after I blew rod due to Oil starvation at the track about 2 years ago.

- - - Updated - - -

Most importantly.... what wheels? And are you using a centering ring?

Like this....

I have Rota G forces and yes, I am running plastic centering rings.

 

[DDozier]

Does anyone have recommendations on the best way to go about fixing this? Do I have to replace the whole hub, or can I replace just the broken stud? Part numbers and cost estimates and where to buy these parts would be extremely appreciated.

ARP makes replacement studs and extra length studs, you do not have to replace the hub unless the hole that you are pressing the stud into has been rounded out by the force of the stud before it broke off. The ARP extended wheels studs are too long if you leave them full length and will in most cases force you to run open lug nuts. I ordered the extended studs and cut them to the length I needed as the standard stud length was too short for my wheels and that is the main reason I was changing them. You can search here on Prime for replacement steps but if you do the extended studs the rear wheel hubs will most likely need to be removed from the car so the old stud can be pressed out and a new stud pressed in, the front hubs can stay on the car as there is more room to get the old stud out and the new one in.

Studs are sold as each, sets of four, and sets of five. If I remember right they were about 20 bucks for a 5 pack. If you do them just take the time to do them all. One failure is most likely to be followed by another. This can be done by the average DIY guy if you have basic hand tools, but if you remove the rear hubs make sure you order new spindle nuts (2) as they are designed to be used one time then replaced.

http://www.acuraoemparts.com/delray...MT&catcgry5=DRIVESHAFT&ListAll=All&vinsrch=no

Dave

 

[CL65 Captain]

I have Rota G forces and yes, I am running plastic centering rings.

I was snapping studs. Even snapped several ARP studs. Removed the centering rings and NEVER had another problem.

 

[illwillem]

I used to snap studs on my s2000, it was also because I ran plastic/delrin center rings. apparently they were heating up and deforming then would cool oblong and stress the studs. When I started to track seriously i noticed that anything plastic around the brakes would melt and warp including centercaps and rings. You could try and get some brass ones (i would stay away from aluminum since it can deform if pinched) or get some other wheels that dont need a hubcentric ring. Fun laps.

 

[CL65 Captain]

Or run no centering rings at all. That fixed my stud snapping problem. Cody @ Lovefab had the same Enkei RPF01s and told me he never ran centering rings either on the 650hp+ shop car.

 

[skyline23]

Weird. I assumed the centering rings would help reduce stress on the studs and prevent breaking them, that's the whole reason I put them on I the first place. Once I replace my studs I guess I will try running without the rings and see how it goes.

 

[docjohn]

I have logged many track miles on ssr type c with metal rings,never had a problem.

 

[stonesonsilver]

Thanks. Yep, I have one of the early Comptech superchargers with high boost pulley and AEM FIC. Car dynod at around 375 whp. It is a 91 with about 130k miles, however the motor has been rebuilt by Driving Ambition about 3-5k miles ago after I blew rod due to Oil starvation at the track about 2 years ago

If you don't mine me asking, what was your cause for Oil starvation?

 

[skyline23]

From my understanding, NSXs are pront to oil starvation with high speed, long, banking left hand turns, and that is what happened to me at Laguna Seca.

If you don't mine me asking, what was your cause for Oil starvation?

 

[nsxtasy]

You're not going to have oil starvation as long as your oil is full and you're not driving on high-banked ovals. One long turn on a road course won't do it.

 

[stonesonsilver]

I know the early corvette z06's had this issue with oil staravation but didn't know it was prone on a nsx with street tires.
Any of you running a oil pan baffle? Maybe I should consider this mod for cheap insurance..

As for the wheel stud I guess it's not so bad considering its a 20yr+ car with 130K miles (some track miles too) only to have one wheels stud to give way.
I would suggest to consider metal hub centric rings. I had some made from motorsport-tech.com for a former z06 vette.

btw: the vette had really crappy wheels studs compared to the nsx. Super soft metal.

 

[R13]

I'm confused by a couple of posts above:

1: There are no long-banked-left-hand turns on Laguna Seca...or not that I would call 'long', Did you mean turns to the right?

Because

2: A turn to the left sloshes the oil towards the pickup, not away from it.

Also

3: With respect to banked ovals.....only dangerous if their clockwise (see 2 above). Anti-Clockwise and as long as your driving quickly (hopefully so on a track) you'll always generate enough lateral g to keep the oil from sliding away from the pickup.


Sorry, came here because I've broken a stud before.

I would inspect your other studs and if they look ok, you can just replace the one. It's easiest to remove the hub bearing assembly from the car if it's one of the rears. If it's the front you can do it on the car pretty easily.

If you decide to replace them all with ARP or another extended stud, then you'll want to just remove all of the bearing assemblies. I believe best practice is grinding a small notch in the bearing assy to enable you to fit the extended studs.