Brembo Disk Bell Ring-Hub bolt Failure

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.
http://i463.photobucket.com/albums/qq359/wessbecher/Panoz/GTS/GTSparts001.jpg?t=1253117904

http://i463.photobucket.com/albums/qq359/wessbecher/Panoz/GTS/GTSparts007.jpg?t=1253117777

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

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?

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...

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.

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.

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/vbulletin/showthread.php?t=944482&highlight=rotor

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.

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.

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.

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.

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.

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.

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.

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

Jim-cost wise you definitely lucked out on the RA brakes. I had no issues with them. They really held up well.
Kevin makes a valid point with the heavier initial braking loads due to the HP advantage on the GTS's. Kel you are running higher HP's and soon to increase again. What brakes/rotors are, or will you be, running?
I am going through all the hardware replacements now. It wasn't the hat hardware that failed though; it was the 5 bolts which pass through the adapter into the hub. They appear to be just 5/16 hardened socket head cap screws. (My previous comment about stripping aluminum threads was crap. Disregard it. The adapter is aluminum but the bolts thread into the steel hub) A previous time when I was at the track I saw a Cobra shear off his (I am estimating by eye) 5/16 hub bolts; I think he had 8 of them. He had huge meats on the rear so in passing, I wondered if he just overstressed the entire hub assembly. Now here I am with a similar situation.
I believe Brian G. has commented in previous threads that he also has a similar replacement schedule. Definitely critical!

CRITICAL!!!! Change the spindles, 4 bars, hubs, most hardware (especially what connects the wheels to the frame), etc.

I even had to have the rear end housing sent to panoz to have all the bracketry replaced. Over time they had twisted and cracked from the heat and then the nut that holds the rear hubs on skipped a thread..... There is nothing on the car that shouldnt be replaced. My car is almost 10 years old. Thats a lot of abuse!

Just think of it this way...ever part you take off becomes a perfect backup for the trailer. After a while you will have backups to everything and track repairs are easier. I even keep the used bolts.

Points well made! It does get spendy, but thats what we all signed up for.

Jim-cost wise you definitely lucked out on the RA brakes. I had no issues with them. They really held up well.
Kevin makes a valid point with the heavier initial braking loads due to the HP advantage on the GTS's. Kel you are running higher HP's and soon to increase again. What brakes/rotors are, or will you be, running?
I am going through all the hardware replacements now. It wasn't the hat hardware that failed though; it was the 5 bolts which pass through the adapter into the hub. They appear to be just 5/16 hardened socket head cap screws. (My previous comment about stripping aluminum threads was crap. Disregard it. The adapter is aluminum but the bolts thread into the steel hub) A previous time when I was at the track I saw a Cobra shear off his (I am estimating by eye) 5/16 hub bolts; I think he had 8 of them. He had huge meats on the rear so in passing, I wondered if he just overstressed the entire hub assembly. Now here I am with a similar situation.
I believe Brian G. has commented in previous threads that he also has a similar replacement schedule. Definitely critical!

Uwe, my RA had the standard rotors/pads/calipers on it when I got it. I have changed to rotors locally CNC'ed from blanks cast in Italy (half the price of using PFC rotors). I am also running Carbotech endurance compound pads.

I think that the additional load generated in a GTS is probably related as much or more to the torque compound of the pad being used. Remember that the RA comes with PFC 97's which are a low torque pad. Similarly the endurance pads I run are not as high torque as what you will run in a GTS for sprint type racing. I note a couple of comments about RA brakes being lower spec. The only major differences are the pads/lack of bias adjuster/larger rear master cylinder, all other components are essentially the same as the GTS as far as I am aware.

On the design side though Uwe I point out with interest that the RA brakes use 8 aircraft grade bolts to attach the disc hub to the wheel hub. There are 8 floater bobbins and bolts between the disc and disc hub. I see that the newer brakes use only 5 bolts between the disc and the disc hub/hat. The reduction from 8 to 5 bolts will mean that there is a less efficient clamp between the parts requiring a larger dia bolt and a higher torque loading to prevent fatigue. What dia are the 5 bolts and what is the torque loading on them?

Personally I am happier with the 8 bolt arrangement and will not be going out of my way to change this anytime soon !! (especially given your experiences).

For the record the PFC97s feel great once you get some speed in the car and can get them up to temp. Traqmate shows that the GTRA is hitting 141 on VIR's main straights now. Brakes are my favorite part of the car.

For the record the PFC97s feel great once you get some speed in the car and can get them up to temp. Traqmate shows that the GTRA is hitting 141 on VIR's main straights now. Brakes are my favorite part of the car.

If you like them now Brian, then you will absolutely love them with a higher torque compound pad fitted. The 97's are a great all round and long lasting pad, but compared to some of the more recent high torque compounds they would not cut the mustard in sprint racing (i.e 6 - 8 lap events).

Kel.

The performance and stress on the brakes is also directly proportional to the grip of the tire. If you can lock up your tires, no need for more agressive pads.

The performance and stress on the brakes is also directly proportional to the grip of the tire. If you can lock up your tires, no need for more agressive pads.

:grinno: what a true statement.

The performance and stress on the brakes is also directly proportional to the grip of the tire. If you can lock up your tires, no need for more agressive pads.

Agree Jim. Are you easily able to lock the brakes in your car with good DOT's or used slicks on? To really get the best out of an RA braking wise I have found that you really need to change the rear master cylinder down in size and put a balance adjuster in (both of which the GTS and GTWC have). Without these mods the car will lock front brakes a lot more easily, particularly on DOT's.

I have only had wheel locking occur (fronts regularly) when I had a shock absorber problem, no balance bar and the large rear master cylinder (which puts more bias to the front brakes). When I had this issue I rebuilt the front shocks and added the balance adjuster and smaller rear master cylinder. The car was then able to be bench set up (balance bar) as per the GTS manual. This balance setup was then so close to what I need to run at my local track I now leave it alone. In my car in its current configuration, I believe that I would benefit from a higher torque pad for sprint racing than say the PFC 97 or the Carbotech 9 compound that I currently have.

I guess this is also very dependent on the track surface you race on. Whether it is true or not I am unsure, but I have been told that many of your Stateside tracks are a bit slicker than the asphalt surfaces we generally race on over here. This could be due to lower ambient temps over here as much as anything though.

Kel.

" The reduction from 8 to 5 bolts will mean that there is a less efficient clamp between the parts requiring a larger dia bolt and a higher torque loading to prevent fatigue. What dia are the 5 bolts and what is the torque loading on them?"-
Personally I am happier with the 8 bolt arrangement and will not be going out of my way to change this anytime soon !! (especially given your experiences). [/quote]I blew the quote format, you guys get the idea.

Kel, based on my recent experience I was thinking the same thing. The 5 sheared bolts are 5/16 hardened and black oxided socket head cap screws (Adapter to hub). I have 10 bolts attaching the adapter to the rotor using the hats. I don't have my RA anymore so I cant do a visual on the differences. I believe you are saying that you have 8 hub to adapter bolts. as well as 8 adapter to the rotor bolts?

So the manual states:
Rotor Disk to Rotor hat 60 in. #'s 10/wheel
Rotor Hat to Hub 25 ft #'s 20 total

So it appears on the GTS's, even the older style had only 5 bolts/wheel

I did like my PF brakes with the exception of occasional front lockup which as you stated the balance bar and cylinder change would correct. I never had to worry about this type of failure.

I believe you are saying that you have 8 hub to adapter bolts. as well as 8 adapter to the rotor bolts?

Yes that is correct. At least on my RA.

I went ahead and replaced the new hat and hardware on the right wheel which broke. I also disassembled the left hub/rotor assembly to inspect the hat to hub bolts and out of these 5 bolts, I found one loose and 2 snapped off completely; which left only 2 bolts holding this rotor in place. Clearly this rotor was just waiting to let go.

Here is a pic of the broken bolts.
http://i463.photobucket.com/albums/qq359/wessbecher/GTS/bolts002.jpg?t=1255187072
My hand was a bit shaky, but clearly these bolts have been snapped for a while now, judging by the rust at the break points.

So here is the brand new hat which Panoz is now outsourcing to someone other than Brembo. The new non-Brembo parts are now gold anodized. The color is the clear distinction whereas the Brembo hat is black anodized and actually has the Brembo P/N laser engraved on it.
http://i463.photobucket.com/albums/qq359/wessbecher/GTS/trailer001.jpg?t=1255187357

Without getting to much into the dimensions, the new hats are .010 thicker at the mounting flange than the Brembo hats. As we all know the bushing (bobbins in the manual) have a fixed length which determines the float of the rotors. The Panoz engineer stated that they would like to see a min. of .014 clearance (float). I inspected all my bushings and I see a .004 overall length variance over all 10 bushings. The tolerance stack up between the hat flange and the rotor flange creates a problem. My clearance with the new hat calc.s out at only .004 clearance (due to the thicker hat). With the out of plane condition of the rotor I end up with no float when pulling/pushing the rotor by hand. When I turn the individual bushing/bolt sub-assemblies I can get them to move from flat to flat (stop to stop). Panoz stated that they have sold many of the new gold hats and have not had reports of problems. This is mainly an FYI, but it could be an important one. I have 3 track days on the car since assembly and haven't noticed any difference in performance. My understanding is that the float is to allow heat dissipation by letting the rotors find a neutral position between the pads. Can anyone confirm that this is the main purpose of the float?
I was under the gun when I found the left side broken the evening before I had to leave to the track. I had no time to order a new Hub to replace the one which had the 2 broken bolts inside the treaded holes. I very slowly and carefully (carbide) drilled out the hardened bolts to the minor thread diameter and then counter-bored the hubs from the backside and was able to drive the remaining thread (which now looked more like a helicoil) out through the other side of the hub. So I couldn't help but wonder why some of you are replacing the hubs. This part is so beefy that I don't think it would ever fail. Why aren't you guys just driving out the bearing races (at bearing replacement time) and reusing the hubs? Has anyone ever had a hub actually fail?

I have had front spindles shear off. I have not had the rear hubs fail and I agree they are beefy. We do drive the bearing races out and reuse them but all parts fatique. And if you are truely pushing a car to its limits ALL parts will fail and the $100 hub is not worth a big failure at speed. Every part needs to be replaced and whatever schedule you use depends on how hard you drive. We drive HARD and parts break. I wish we drove the same tracks to really understand... 1.58 @ Daytona, 2.13 Sebring, 1.27 homestead w/ banks 3/4, 1.29 without banks, 1.30 Barber, 1.28 Mid-O, 1.33 RA or better (have not been with current mods) to name a few....and those are all repeatable times.

No doubt you push harder than I ever will. I am trying to figure out the correct balance of economies for my level. I'm definitely not a slouch though. I've been doing pretty well.

I wasnt comparing skill levels more just helping determine the levels. We all have room to grow. We determined what we thought was a good replacement routine based on racing hours of use. The routine was developed by failed components. It took years to figure it out. We have owned 2 GTS for 5 years. We didnt replace anything the first year or so and so alot of failures so we then changed everything and got a baseline and went from there.

No worries, I got the relevance you were drawing. I agree, I do need to consider the level you are at vs. mine. It does become relevant I think. Tons more power and traction creates exponentially more strain on all the components. The only reason I referenced my driving level is because I am already pushing this car pretty hard even though it is new to me. Again more strain, relatively speaking!

Do you feel that I should be concerned about the lack of rotor float due to stack up tolerances?

not sure about the bolt tolerances. What did PAD stop providing the Brembo part? Is the gold one cheaper, stronger???

I would use the parts that work together even if its more money. Cutting corners to save a buck has never worked for me in racing.

One thing I have always loved on the cars is the brakes. We run top of the line SRF fluid and have always been rewarded with great brakes.

They didn't say why but it was probably to save $'s. On the manufacturing side, not ours. They had it reverse engineered and outsourced. It definitely is not for strength, as it looks to be the exact same design. They stated that the flange thickness that I measured was exactly on nominal to their +/- .005 tolerance. As I stated previously the Brembo part was .010 thinner. The gold anodize is a type II (not a hardened Type III). I checked it! They just changed the color to be able to easily distinguish between the newly outsourced vs original Brembo parts.

I wish they had redesigned it and added 3 more bolt holes to the hat and hub. Based on my experience, that would have been a worthwhile improvement.

I would buy the brembo part...will they still sell you the brembo one?

Dont know, but I will find out.

I went ahead and replaced the new hat and hardware on the right wheel which broke. I also disassembled the left hub/rotor assembly to inspect the hat to hub bolts and out of these 5 bolts, I found one loose and 2 snapped off completely; which left only 2 bolts holding this rotor in place. Clearly this rotor was just waiting to let go.

Here is a pic of the broken bolts.
http://i463.photobucket.com/albums/qq359/wessbecher/GTS/bolts002.jpg?t=1255187072
My hand was a bit shaky, but clearly these bolts have been snapped for a while now, judging by the rust at the break points.

Uwe, where are the cap screws breaking with reference to the joint that they are securing? Are they breaking just past the joint face within the threaded holes in the hub, or at the joint interface?

I note that the cap screws are threaded for their whole length, this is not very good engineering as they should have a plain shank portion to bear evenly against the sides of the holes in the hat (you will never find this in a well engineered aircraft component thats for sure).

Are you able to drill out the holes in the hats and drill/tap the holes in the hubs to go up a size with the bolts? If you can do this, I would. I would also change to UNF thread form (as the cap screws appear to be UNC) and use an aircraft grade bolt.

Kel.

Kel, Excellent suggestions on the mods. Once I put out some of those other fires I'll circle back to that.

Strangely one bolt broke off 2 threads down into the hub and the other 3 threads down. Both well beyond the parting lines. What are your thoughts on that? I believe it indicates a lot of flexing of the bolts. That makes me wonder if I should actually go up to a harder bolt. A harder bolt could actually snap earlier under repeated flex. These are through, not case hardened.

I'm hoping to get my lift soon. I have a handle on a used Nussbaum (German quality) for about $1900 (new is somewhere around $4.5K) Then I'll have space to put in a manual lathe, Bridgeport mill, parts washer and other small stuff that I have had in storage since I sold the biz. I'm really excited, I feel like an arm has been cut off since I haven't had access to anything. That will give me the opportunity to get into the kind of fixes you are recommending. Then it is only a matter of having the time. I guess we are all feeling that pinch.

Kel, Excellent suggestions on the mods. Once I put out some of those other fires I'll circle back to that.

Strangely one bolt broke off 2 threads down into the hub and the other 3 threads down. Both well beyond the parting lines. What are your thoughts on that? I believe it indicates a lot of flexing of the bolts. That makes me wonder if I should actually go up to a harder bolt. A harder bolt could actually snap earlier under repeated flex. These are through, not case hardened.

I'm hoping to get my lift soon. I have a handle on a used Nussbaum (German quality) for about $1900 (new is somewhere around $4.5K) Then I'll have space to put in a manual lathe, Bridgeport mill, parts washer and other small stuff that I have had in storage since I sold the biz. I'm really excited, I feel like an arm has been cut off since I haven't had access to anything. That will give me the opportunity to get into the kind of fixes you are recommending. Then it is only a matter of having the time. I guess we are all feeling that pinch.

Yes, like you I am thinking that the failures are related to cyclic fatigue of the bolts. The failure point is probably the point of flexure given the tolerance/fit of a UNC type fastener. This convinces me that going up in fastener cross sectional area (edge distances allowing) is the best fix Uwe, in combination with using a top quality fastener with a plain shank portion for dealing with brake torque bearing loads.

Kel.

It'll be awhile before I get back around to that, considering some of my other fires. In the short term I'll keep a seriously close check on the bolts. I think you are 100% right on with the fix. I'll check to see what up-sizes we have clearances for.

I agree with the changes except one problem. Dont you think Brembo knows what they are doing and designed something that works? Maybe you had a previous owner that decided to use his own hardware in lieu of paying out the nose for Brembo hardware?

I agree with the changes except one problem. Dont you think Brembo knows what they are doing and designed something that works? Maybe you had a previous owner that decided to use his own hardware in lieu of paying out the nose for Brembo hardware?

Brian, great idea regards checking that the hardware used is actually correct, I have assumed this to be the case. Does your car have fully threaded cap screws fitted such as Uwe has found in his? If so I would not be happy to run this fastener setup in my car, period.

Regards your question about Brembo's design capabilities, I cant answer that as I am a first time Brembo owner and have had no issues as yet. There are 2 observations that I would make though;

1. The GTRA has a higher spec attachment system (8 bolts) than what is now on the GTS (5 bolts) and I find that intriguing given the far higher load that the GTS brake system operates under.
2. There are countless manufacturers out there in the racing world producing products which fail in the environment for which they have supposedly been designed to operate in. I.e. no manufacturer is immune to design shortfall. I have seen this many times in the aircraft world as well.

Kel.

You both make vary valid points. I wonder who actually spec.'ed these 5 bolts in question. The hardware on these didn't come from Brembo but rather from Coleman. Remember these are old technology Impala style hubs. It does make sense to have a shouldered bolt if I can find one of the proper shoulder length. I never posted close up photos of the failed hat. The threads were imprinted on the Brembo hat flange holes. Presumably this happened when the 2 bolts snapped and the hat tried to spin and therefore dug into the sides of the screw threads. I dont know what types of loads were induced upon these Impala hubs in the day or what they were designed to withstand. Needless to say I'll be inspecting these bolts often now. Hopefully I wont have any more failures to report; nor anyone else.

You guys are a great resource for a new guy. I replaced my mounting bolts yesterday. All were rusted near the bolt shoulder and 1 snapped as soon as I put a wrench on it.

Would not have thought to check them without this site.

Thanks to all.

Rich

Rich, I'm glad these discussions helped you. This is definitely a safety issue. Great that you caught it before an incident. I was told by PAD that they hadn't heard of this failure. That means most everyone has been doing the replacements on a correct schedule. Unfortunately yours and mine hadn't been done in time.

Uwe, my RA had the standard rotors/pads/calipers on it when I got it. I have changed to rotors locally CNC'ed from blanks cast in Italy (half the price of using PFC rotors). I am also running Carbotech endurance compound pads.

I think that the additional load generated in a GTS is probably related as much or more to the torque compound of the pad being used. Remember that the RA comes with PFC 97's which are a low torque pad. Similarly the endurance pads I run are not as high torque as what you will run in a GTS for sprint type racing. I note a couple of comments about RA brakes being lower spec. The only major differences are the pads/lack of bias adjuster/larger rear master cylinder, all other components are essentially the same as the GTS as far as I am aware.

On the design side though Uwe I point out with interest that the RA brakes use 8 aircraft grade bolts to attach the disc hub to the wheel hub. There are 8 floater bobbins and bolts between the disc and disc hub. I see that the newer brakes use only 5 bolts between the disc and the disc hub/hat. The reduction from 8 to 5 bolts will mean that there is a less efficient clamp between the parts requiring a larger dia bolt and a higher torque loading to prevent fatigue. What dia are the 5 bolts and what is the torque loading on them?

Personally I am happier with the 8 bolt arrangement and will not be going out of my way to change this anytime soon !! (especially given your experiences).

Kel, you may have shared this but can you provide more info about the rotor blanks you're using? Where did you get them, etc.? A few of us are shopping for rotors for the GTRA and this is an issue.

Thanks,
Jim

Interesting thread - love all the discussions.
So, thought I'd share - I have not had any issues with this topic, but upon my winter projects -- the rumbling noise I heard in the wheels, was not the bearings - however:

http://dcazin.c4-motorsports.com/LS1/SDC12762%20%5b1280x768%5d.JPG

I guess you used them up COMPLETELY!

I guess you used them up COMPLETELY!

The way I see it, he still has half left...:sarcasm1::lol:

This is the discussion some of us were having. What is causing the excess wear at the mounting holes? I am going to talk to a tech at PFC when they get back in the office after the holiday. I would like to get the correct torque specs too.

The way I see it, he still has half left...:sarcasm1::lol:

This is the discussion some of us were having. What is causing the excess wear at the mounting holes? I am going to talk to a tech at PFC when they get back in the office after the holiday. I would like to get the correct torque specs too.

Cool - please share if you find them - mine are as "tight" as they were when I took them off. :confused:

The wear I thought, was odd too - I am just surprised I did not have other issues. Could have been bad.

That's scary. We need to get this figured out. I nominate Jim Pomroy to figure this out and report back. We're behind you all the way, Jim.

That's scary. We need to get this figured out. I nominate Jim Pomroy to figure this out and report back. We're behind you all the way, Jim.

Great idea. We'll all send our broken stuff to Jim, Jim puts it on his car and tells us when it's really used up, not just junk! I don't want to be behind him when he finds out!

OK, a little more seriously, it seems to me the issue could be hardware quality. I think the issue of what the proper hardware really is needs to be settled. Are there any advantages to the newer GTS system? Could John Leverett shed some light on all this and some of the GTS guys?

Mike

We had one set of rear pfc rotors that lasted forever. I am talking years of racing. We wore the vanes off the rotor. No cracking or anything. The brembo stuff never lasts that long.

Curious why PAD switched on the GTS to brembo instead of PFC. It might have been a sponsership deal or something like that?

Snoop it out!!!

Great idea. We'll all send our broken stuff to Jim, Jim puts it on his car and tells us when it's really used up, not just junk! I don't want to be behind him when he finds out!

Mike

You sure won't be in front of me any time soon....:loser::lol:

Jim, That's true, but lapping is allowed.:eek7: Never know what can happen when fear takes over, off the track would also avoid the exploding brake parts as you go by! Remind me to use my off road Cepek's when you are doing your brake durability testing.

By the way GTS drivers, I have three new GTS Brembo rotors I'd like to trade for PFC rotors. If interested send me a PM and I'll give you the details. I'm pretty sure they are rears, but I need to remeasure them to confirm as well as rights or lefts. I'd consider selling the three for $450 plus shipping. I'm looking for two or three PFC rotors to complete a set for my GTRA. CRS strikes again.

Mike

See Devin, I told you you use the brakes too much!! :-o

Kel, you may have shared this but can you provide more info about the rotor blanks you're using? Where did you get them, etc.? A few of us are shopping for rotors for the GTRA and this is an issue.

Thanks,
Jim

Jim, I purchased the discs ready to fit from an Auckland New Zealand based company called 'Znoelli' http://www.znoelli.co.nz

I supplied Znoelli a front rotor as a sample and they then CNC machined a pair of discs for me out of blanks that I beleive are sourced by Znoelli out of Italy. I used these discs in the 6 hour enduro with great success.

If disc pricing/sourcing is an issue in the States and interest is strong enough, I would look at getting a production run done here by Znoelli and sea freighting them up to the States. Pricing would be dependent on order size I expect.

Kel.

Jim, I purchased the discs ready to fit from an Auckland New Zealand based company called 'Znoelli' http://www.znoelli.co.nz

I supplied Znoelli a front rotor as a sample and they then CNC machined a pair of discs for me out of blanks that I beleive are sourced by Znoelli out of Italy. I used these discs in the 6 hour enduro with great success.

If disc pricing/sourcing is an issue in the States and interest is strong enough, I would look at getting a production run done here by Znoelli and sea freighting them up to the States. Pricing would be dependent on order size I expect.

Kel.

Kel, did you ever look into this?

Eric, Gator AC had Coleman make some rotors for him. I am sure he will chime in and give details.

David

When we switched to the new style GTS rotors on the GTS cars.....Panoz told us that they could no longer get the old ones. The new style was common to other race cars (I think they said some Nascar series, but not sure) and thus availability was the issue.

A friend had Coleman make several similar rotors for his Mustang race car. I suspect that will be our next step as the Brembos are pricey and don't seem to last as long as the old ones.

Somebody break the Coleman ice...

BTW we NEVER reuse the fastner set.

Kevin

Ding:p

I am currently running a set of Coleman rotors made to my specifications up front. The machinist misread the drawing and I did have to take them to a local place to take a few thousands off of the mounting plate thickness. The drawing has been edited to keep that mistake from hapening again. I'll get back to you on how they wear after a few years.

My PFC97 pads last about 60 hours. The rear PFC rotors are on the 2nd set of pads right now. They will do 120 hours easy, maybe 180. The fronts would be close but re-using hardware and not checking them means the mounting holes have worn excessively on the left side and I needed to replace before the braking surface was used up. I put a used rotor on and I have no idea how many hours are on it. The log book says they were used when they were put on. Check your brake hardware after every event.

Keep in mind braking styles and hp make a difference in how the consumables last. I'm running stock GTRA power and nothing catches me under braking. YMMV