Brembo Disk Bell Ring-Hub bolt Failure

[Wess-RA]

This failure happened under braking going into a relatively slow corner. Had it been the next high speed corner it could have been disastrous. Bolts sheered off.

This is on the GTS Brembo rotors/bellring Brembo P/N 90.1290 S/N0707010 . I know that Brembo recently came out with a different version. Can anyone identify this as being the new or old version? I was told by the seller that this car had the new version with the new hardware.

[panozracing]

that is the new version. If they reused the hardware you will have that problem. When we change rotors we change everything. I change the hubs every other rotor

[Wess-RA]

Brian,

Do you buy it all from Panoz or do you go Brembo direct. Thanks for the feedback, that it is the new rotor. What do you look for in telling the difference? Same things to look for in the rear?

[panozracing]

the rears have not changed for 10 years. The fronts have a curved slot in them and the edge is concave on the new rotor. I buy EVERYTHING from PAD. We need them to stay in business and their prices are always with 10% of finding them on my own which usually isnt worth the time and potential mistakes...

[Wess-RA]

Thanks for the details Brian. I've got an e-mail in to them for parts.

Your previous message stated "If they reused the hardware you will have that problem". Does that mean the previous owner could have used the wrong hats/hardware (old style hats and bolts on new style rotors)and that lead to the failure-or rather that the hardware had too many hours of stress even though it is matched correctly to the new rotors? I was once told that the hats/hardware alone are something around $350/wheel. That seems rather steep for just flanged bushings and high strength bolts. I am hoping that price is wrong.

[panozracing]

sorry for the confusion.

I was talking about too many hours on the hardware. I change the rotor to hat hardware everytime I change rotors. I change the hat to hub and the hardware sometimes when I change rotors but no mare than every other rotor. I dont remember how much they cost. I know they are at least 100 for the hat and brembo hardware is stupid expensive. Our rotors last a long time and if they break at high speed things will be much worse so the money is not something I will risk.

[jmimac351]

Uwe, thanks for sharing and the reminder about this stuff. Check here for an fyi on cost and I'm sure you'll get the info you need from Josh or Brandon at PAD. This particular part of the car is pricey for sure.

http://www.automotiveforums.com/vbul...ighlight=rotor

[Wess-RA]

Thanks for the link Jim. Here are some prices for the guys who are putting them into spreadsheets.

GTS9-5016 Front Hub $217.79ea
GTS7-4212 New Style rotor adapter $231.64ea
GTR8-3229 Rotor Adapter Bolts $0.70ea
GTS9-3603 Tailpipe $67.15
GTR9-3609 Exhaust Hanger $6.39
PZR7-A261 Hardware $0.46
PZR7-A265 Hardware $0.17
GTR8-A077 Hardware $0.16
GTS9-2132 Body Mount $22.34

I was surprised to find that the Rotor Adapter is made of aluminum. It was suggested that the bolts may have been over torqued by the previous owner leading to stretching and subsequent failure. I am a little doubtful of that possibility in that I think the aluminum threads would have stripped out before damaging high tensile/shear strength bolts. Nonetheless I am swapping out hardware on both sides.
FYI Panoz tells me in order to be able to more easily identify the "new Rotor Adapters" they are now gold anodizing them, to differentiate. Also the new style adapter has a rotor bolt circle of approximately 8 1/8”. The old style is approximately 7 5/8”. The part number 90.1290 etched on the adapter is the new style.

[jmimac351]

Uwe, so that's almost $700 per corner for rotor, hat, and hardware. Plus $218 for the hub, correct? I'm just about due for front rotors so that's something to plan for, for sure.

[Wess-RA]

Jim, I hope I didn't confuse the issue. This is for the Brembo rotors and adapters. I believe they are only used on the GTS cars, yes? My RA car had Performance Friction rotors and still used the Brembo calipers. So I don't know if these steep numbers apply. I haven't heard anyone say that PF changed their design.

[jmimac351]

I have no idea. I hope you're right though. Maybe someone will clear this up or I'll call Brandon next week. I generally work from the assumption that most things are interchangeable between the cars.

[Wess-RA]

What I first noticed as being different when I got the GTS was that when I pushed the car I could hear the brake pads dragging over the slots of the rotors. Upon disassembly I realized the Brembo hardware with hats allows the rotor to float. I believe they could be changed from PF to Brembo, but I don't know if it would be worth the extra $'s. I don't know if the performance is that much superior; and I have now eperienced that failure. I have a lot to learn about this car. Brian would definitely know better than me, having been there for a long while now.

[jmimac351]

Uwe, what was the chassis number on your GT-RA? My GT-RA has floating rotors. Chassis 25.

Edit: did some searching and looks like you're right about the difference...GT-RA has PFC rotors, GTS Brembo (which requires new hats, etc.) I assumed it was the same and thought this talk meant I would need to change. Looks like the GT-RA guys lucked out on this one.

[Cobra4B]

What makes the PFC stuff better? We've had great longevity w/ our stuff and were able to buy a bunch of spare rotor rings for $100 ea. when we first got the car.

[boothkc]

Uwe,
you have the new style hats and rotors. The hubs are unchanged. Panoz changed these as the old ones were hard to get and were Panoz specific. New ones are used in other race cars....I guess.

You should hear the rotors float and move in the hats when you roll the car around, especially cold. There is alot of slop here and it's an unusual noise.

We generally change the spindles every 2yrs, rotors 1x/yr, hats everyother year, pads 1-2x/ season... all bolts and rotor hardware with every removal.

We've broken everything at onetime or another so no short cuts here.

I would guess that hat mounting bolts fatigued. Replace all of them and verify torque specs in the GTS manual!!!!!

BTW the PFS parts in the GTRA cars are not the same or interchangeable with the GTS Brembo brakes. I think the GTRA stuff is inferior and braking at GTS speeds is a big deal! No trade offs here.

Also it is not really possible to distort the bolts that mount the rotor to the hat (adaptor) these have internal stops and will tighten down such that the head and the nut spacer bottom out. This allows the rotor to float on the hat. Again lots of slop/noise here when cold. If you over tighten these you'l just strip the rotor mounting bolt...not pinch the hat.

Kevin
GTS