Guys-
I wanted to hop in here to try to clarify a few things as best I can.
First off, at least with our replacement rings (Im not entirely clear if the OP bought DBA or something else) we recommend 13nm as the specified torque setting. I cant speak for other offerings though.
But this spec is based on a new assembly. If the hardware is heavily fatigued, then you may have hardware failure much like what is being discussed. I cant speak to the quality and longevity of a fastener we dont supply.
(As a side note, I'd rather find out my fasteners were going to fail during assembly than on the track, but thats another matter.)

That said, I wanted to mention that the Nissan GTR community has also been doing these replacement rings for a few years now with much success, and they have found sources for replacement bobbin hardware, so I know its out there somewhere. So in a case where a fastener has broken or a part of the bobbin assembly has been damaged, there are parts available without buying another complete rotor assembly. I have tried to source this hardware for us to resell simply to make it easier on the end users, but being that its a patented design, they arent all that fond of selling them to us in bulk.

I think the idea that another member mentioned, where he sourced the bolts from another supplier is probably reasonable as well, as long as its a strong enough grade of fastener without issues from extensive heat exposure. Since the 'magic' of this system is in the bobbin not the bolt. But this is not something we can safely recommend when we havent done any testing of our own.

To clarify a few other things.
- within the DBA lineup, the tri-wing and the hex head bolts are only compatible with DBA's two-piece rotors. NOT these Brembo bobbins.
- the link to the zeckhausen page is showing a mclaren anti-rattle clip, which isnt the same configuration as the bobbin setup on these rotors, so that torque spec of 62 lb.in doesnt apply

I hopes this helps, and I hope that the OP manages to source some fresh hardware without too much trouble.

Let me know if I can provide any additional info.

 

^thanks for posting. They are the DBA rings I purchased. When I tested the torque on my other OEM bobbin hardware (i never touched the bolts/nuts before), I got initial movement of the nuts at 5 ft-lbs (60 in-lbs). Are you guys 100% sure of your torque recommendation for the OEM hardware?


Side question...do you sell compatible DBA hats for the Z06? I've never seen a full two piece rotor option from DBA for the Z06. I'd be happy to swap over to the DBA hats and hardware.

 

Yes. that spec is verified by our engineers. Its standard across this fastener design for multiple applications.

We do not currently offer a complete assembly for the C7 Z06. Sorry.

 

If my hardware was fatigued, doesn't it make the plan of reusing the OEM hardware completely flawed? The OEM rotor was used for 5 track days and cracked. If that's all it takes to fatigue the OEM hardware, really no one should be reusing these bolts when swapping rings.

 

We agree.
Which is why we suggest replacing the hardware. But not every case requires it. Its likely that most times the hardware should be replaced though, and this is particularly true with any race parts.
In the case of our two-piece systems, our bolts dont require replacement, only the lock nuts which are a one time use. So we supply the nuts with each ring.
Again, we'd prefer to supply new hardware, but we dont have access to it.

 

I sell a good amount of the Z06 rings and plenty of DBA rotors in general and the hardware has never failed.

It would seem like I should consider making a hat and hardware solution that is more reliable than what GM has provided. I may have better access than DBA to get some hardware. I would reiterate what DBA has said i.e. the hardware has not really been an issue and we have done this for awhile.

Ken

 

Any chance your torque wrench is out of calibration? 85 pound inches is pretty much pinkie tight.

 

Nope. I checked it.

 

Damn...

I don't recall putting locktite on my 2 piece unit. I ran them in dry and used the wire to "secure" them so they wouldn't back out.

I did see where they were 85 lb in, dry.

 

Dry is fine with the wire. For competition use this is probably preferred to the potential hassle/failure of removing them with red loctite. For the street owner red would be more ideal as most guys don't have safety wire pliers and seldom if ever replace the rings.

 

The OEM rotor (both the ring and the hat) are made in the USA.

 

I agree. I do have one issue with red loctite and that is the difference you get when you torque dry vs. wet threads. You will over torque the threads using a wet loctite.

Elmer

 

I bought a wicking grade locktite. 290. Put it on after torquing.

 

Ah soooooo! Ok, I can go with that.

 

Not the rotors that they were putting on the Z51.

 

The multicast basically one piece rotors provided for the Z51 aren't the same type of rotors that are provided on the C7Z. Even though some people think they are two piece rotors the Z51 rotors can't be taken apart. They are made as one piece. Besides I don't know what being made in China really means. As long as the part is made to specification it will work just as well as if it was made in any other part of the world.

Bill

 

My first replacement rotors from my Z51 had a "Made in Mexico" sticker on them. Then those were replaced within 500 miles or so due to pitting in the steel of the rotor face. Those got replaced again- same stickers and then again they are pitted- Great stuff! Low quality steel. Looking for replacements.

 

I need an engineering refresher but isn’t metric grade 8.8 = grade 5 SAE?






DBA NAS nut on a GM 8.8 Bolt?



Should we make these too?

 

 

I have nuts and bits and a limited supply of bolts for the tri-wing design