Lugs loosening up at the track
08-15-2014, 12:51 AM
#21
Le Mans Master
Thread Starter
The wheels are used wheels. The 3rd and 4th session had minor lug loosening... Much better than the first two sessions.
It seems that the inside of the wheel fits into the beveled rotor hat area and the wheel is sitting flush to the hat to my eye....When I hold the wheel against the hat, there is no wobble. The spacer I was sent I believe is 4mm thick.
I always torque and remove lugs in a star pattern.
On a side note, something was rubbing the inside of the right front wheel when I was turning. Noticed it more so when turning left. There were no signs of any wear or rubbing on the caliper or rotor. No wheel weights were disturbed, yet the outer 1/3 of the inner barrel of the right front wheel appears as if something was scraping or rubbing something!
I'll post pics tomorrow evening, but anyone have any ideas??
It sounded almost like when a rotor is warped or needs to be turned...
I'll also try to post a pic of the wheel/rotor hat contact area.
Thanks!
Ron
It seems that the inside of the wheel fits into the beveled rotor hat area and the wheel is sitting flush to the hat to my eye....When I hold the wheel against the hat, there is no wobble. The spacer I was sent I believe is 4mm thick.
I always torque and remove lugs in a star pattern.
On a side note, something was rubbing the inside of the right front wheel when I was turning. Noticed it more so when turning left. There were no signs of any wear or rubbing on the caliper or rotor. No wheel weights were disturbed, yet the outer 1/3 of the inner barrel of the right front wheel appears as if something was scraping or rubbing something!
I'll post pics tomorrow evening, but anyone have any ideas??
It sounded almost like when a rotor is warped or needs to be turned...
I'll also try to post a pic of the wheel/rotor hat contact area.
Thanks!
Ron
08-15-2014, 12:34 PM
#24
Race Director
Think of the rotor hat (wheel mounting surface) as a 9" diameter flat disc and the back pad of your wheel is 7" in diameter. No problem with this, as you have good, solid, load bearing contact. No spacer needed.
Now, with the CCB's, think of your 9" flat disc (hat) and your 7" back pad....
but this time the 9" flat disc has a 0.160" (~4mm) deep section of the center machined out, with a diameter of 6.900". With the back pad of your wheel being 7" in diameter and a 6.9" diameter, 4mm deep section of the rotor hat (wheel mounting surface) removed, you only have a .100" wide ring supporting the entire load you are putting through the wheel, and a 4mm gap under 95+% of the back pad. The spacer fills this gap and allows for solid contact with the entire back pad.
The hats are this way bc that's how Ferrari spec'd them and GM did not want to spend the money to have a hat machined to accept their wheel as it was cheaper to lathe turn a step in the backpad of the wheel to make that diameter fit the hat. Running without the spacer is VERY dangerous on the street, and worse on the track.
Call me tomorrow and I can get you a set.... And I do not recommend driving the car on those wheels until you have them.
BTW, all of the measurements listed above are to illustrate what is going on, and are not precise.
Br,
Daniel
Now, with the CCB's, think of your 9" flat disc (hat) and your 7" back pad....
but this time the 9" flat disc has a 0.160" (~4mm) deep section of the center machined out, with a diameter of 6.900". With the back pad of your wheel being 7" in diameter and a 6.9" diameter, 4mm deep section of the rotor hat (wheel mounting surface) removed, you only have a .100" wide ring supporting the entire load you are putting through the wheel, and a 4mm gap under 95+% of the back pad. The spacer fills this gap and allows for solid contact with the entire back pad.
The hats are this way bc that's how Ferrari spec'd them and GM did not want to spend the money to have a hat machined to accept their wheel as it was cheaper to lathe turn a step in the backpad of the wheel to make that diameter fit the hat. Running without the spacer is VERY dangerous on the street, and worse on the track.
Call me tomorrow and I can get you a set.... And I do not recommend driving the car on those wheels until you have them.
BTW, all of the measurements listed above are to illustrate what is going on, and are not precise.
Br,
Daniel
So it "nestles" into the "void" and builds it up to a slightly higher level that is then available for the mounting surface of the rim to touch no matter what the pattern on the rim (I have seen many)?
If yes, then what a totally stupid way to engineer a brake rotor hat.
08-15-2014, 03:14 PM
#25
Former Vendor
So the spacer is SMALLER in diameter than the machined out surface diameter of the hat?
So it "nestles" into the "void" and builds it up to a slightly higher level that is then available for the mounting surface of the rim to touch no matter what the pattern on the rim (I have seen many)?
If yes, then what a totally stupid way to engineer a brake rotor hat.
So it "nestles" into the "void" and builds it up to a slightly higher level that is then available for the mounting surface of the rim to touch no matter what the pattern on the rim (I have seen many)?
If yes, then what a totally stupid way to engineer a brake rotor hat.
The hats are pre-machined with the Brembo package for the Ferrari 430 and 458 - their wheel has a smaller back pad and bot circle diameter. GM decided to use this rather than to pay Brembo to change things, and had them drill the Corvette bolt circle diameter. If you look at the hats, because of the larger diameter bolt circle, the stud bores are not even centered in the recess.
The engineers know it is not the best way, but they have a budget to hit.
Last edited by Finspeed; 08-18-2014 at 12:38 PM.
08-15-2014, 05:29 PM
#26
Race Director
Yes you are correct.
The hats are pre-machined with the Brembo package for the Ferrari 430 and 458 - their wheel has a smaller back pad and bot circle diameter. GM decided to use this rather than to pay Brembo to change things, and had them drill the Corvette bolt circle diameter. If you look at the hats, because of the larger diameter bolt circle, the stud bores are not even centered in the recess.
The engineers know it is not the best way, but they have a budget to hit.
The hats are pre-machined with the Brembo package for the Ferrari 430 and 458 - their wheel has a smaller back pad and bot circle diameter. GM decided to use this rather than to pay Brembo to change things, and had them drill the Corvette bolt circle diameter. If you look at the hats, because of the larger diameter bolt circle, the stud bores are not even centered in the recess.
The engineers know it is not the best way, but they have a budget to hit.
One poster was smart enough to figure it out himself, I think I probably would have too, but how many casual HPDE noobs would not? Probably most of them. Then let's say a guy buys some used rims and has xyz shop install them. XYZ shop, has the oil change guy bolt them on. You think he's going to notice?
Then you & I & others are on track @ 125 plus with this car waiting for a wheel to come off.
Sheesh.
08-15-2014, 10:46 PM
#29
Race Director
LOL not much to post about lately too busy with work and no time to get on the track 
by the way did i see some finspeed wheels on some cars in the tudor race last weekend? thought the one porsche in gravel trap looked it might have had finspeed rims on it
by the way did i see some finspeed wheels on some cars in the tudor race last weekend? thought the one porsche in gravel trap looked it might have had finspeed rims on it
08-16-2014, 05:13 PM
#31
Le Mans Master
Thread Starter
The spacer is 4mm thick that I got though. Seems a bit TOO thick to me, but maybe it need that thickness for it's structural integrity...???
Any ideas about the below that I posted earlier anyone???
On a side note, something was rubbing the inside of the right front wheel when I was turning. Noticed it more so when turning left. There were no signs of any wear or rubbing on the caliper or rotor. No wheel weights were disturbed, yet the outer 1/3 of the inner barrel of the right front wheel appears as if something was scraping or rubbing something!
I'll post pics tomorrow evening, but anyone have any ideas?? I assume it had to be the caliper somehow, but I didn't see any wear unless it was on the very bottom of the caliper or something. You could hear it!
It sounded almost like when a rotor is warped or needs to be turned...
Last edited by Dr.Ron; 08-16-2014 at 05:30 PM.
08-16-2014, 07:29 PM
#33
Le Mans Master
Thread Starter
No, I don't have them. Feels like metal on metal. I'll have to look at the bottom of the calipers closer I guess.
But if it's that, wheat can I do??
But if it's that, wheat can I do??
08-16-2014, 11:08 PM
#35
Burning Brakes
It looked like the wheel fits into the recess, but I'll measure both tomorrow and we'll know for sure I suppose.
The spacer is 4mm thick that I got though. Seems a bit TOO thick to me, but maybe it need that thickness for it's structural integrity...???
Any ideas about the below that I posted earlier anyone???
On a side note, something was rubbing the inside of the right front wheel when I was turning. Noticed it more so when turning left. There were no signs of any wear or rubbing on the caliper or rotor. No wheel weights were disturbed, yet the outer 1/3 of the inner barrel of the right front wheel appears as if something was scraping or rubbing something!
I'll post pics tomorrow evening, but anyone have any ideas?? I assume it had to be the caliper somehow, but I didn't see any wear unless it was on the very bottom of the caliper or something. You could hear it!
It sounded almost like when a rotor is warped or needs to be turned...
The spacer is 4mm thick that I got though. Seems a bit TOO thick to me, but maybe it need that thickness for it's structural integrity...???
Any ideas about the below that I posted earlier anyone???
On a side note, something was rubbing the inside of the right front wheel when I was turning. Noticed it more so when turning left. There were no signs of any wear or rubbing on the caliper or rotor. No wheel weights were disturbed, yet the outer 1/3 of the inner barrel of the right front wheel appears as if something was scraping or rubbing something!
I'll post pics tomorrow evening, but anyone have any ideas?? I assume it had to be the caliper somehow, but I didn't see any wear unless it was on the very bottom of the caliper or something. You could hear it!
It sounded almost like when a rotor is warped or needs to be turned...
As for the rubbing it's most likely just track debris getting caught in between the caliper and the wheel barrel. Usually only tire turds get caught there but occasionally I'll get a rock or a bolt/screw sandwiched there and it will gouge up the wheel pretty good. Both of my front calipers are beat up pretty bad from getting stuff caught in that area. If you have ever walked a track on foot you would be surprised how much random crap is on the track like nuts, bolts, screws,etc. I wouldn't worry about it as long as you don't see anything caught in there.
08-18-2014, 11:57 AM
#36
Burning Brakes
So the spacer is SMALLER in diameter than the machined out surface diameter of the hat?
So it "nestles" into the "void" and builds it up to a slightly higher level that is then available for the mounting surface of the rim to touch no matter what the pattern on the rim (I have seen many)?
If yes, then what a totally stupid way to engineer a brake rotor hat.
So it "nestles" into the "void" and builds it up to a slightly higher level that is then available for the mounting surface of the rim to touch no matter what the pattern on the rim (I have seen many)?
If yes, then what a totally stupid way to engineer a brake rotor hat.
See how the rotor hat is recessed. The reading on the scale is not a true measurement, I just used that as a visual reference.
08-18-2014, 12:48 PM
#37
Former Vendor
4mm spacer is perfect.
As for the rubbing it's most likely just track debris getting caught in between the caliper and the wheel barrel. Usually only tire turds get caught there but occasionally I'll get a rock or a bolt/screw sandwiched there and it will gouge up the wheel pretty good. Both of my front calipers are beat up pretty bad from getting stuff caught in that area. If you have ever walked a track on foot you would be surprised how much random crap is on the track like nuts, bolts, screws,etc. I wouldn't worry about it as long as you don't see anything caught in there.
As for the rubbing it's most likely just track debris getting caught in between the caliper and the wheel barrel. Usually only tire turds get caught there but occasionally I'll get a rock or a bolt/screw sandwiched there and it will gouge up the wheel pretty good. Both of my front calipers are beat up pretty bad from getting stuff caught in that area. If you have ever walked a track on foot you would be surprised how much random crap is on the track like nuts, bolts, screws,etc. I wouldn't worry about it as long as you don't see anything caught in there.
Also, if material removed from the inner barrel, there may be reason for concern. The barrel stress is very low when compared to the spokes, but if more than .015" of material has been cut away by the contact, you should call John and get his opinion. I am not sure what CCW's barrel thickness is, but I am confident .015" is greater than 10% of the barrel wall.
08-18-2014, 01:59 PM
#38
Le Mans Master
Thread Starter
5mm seems to be the minimum clearance to avoid grooving from track debris. If this noise is something he is hearing consistently, it is likely not track debris.
Also, if material removed from the inner barrel, there may be reason for concern. The barrel stress is very low when compared to the spokes, but if more than .015" of material has been cut away by the contact, you should call John and get his opinion. I am not sure what CCW's barrel thickness is, but I am confident .015" is greater than 10% of the barrel wall.
Also, if material removed from the inner barrel, there may be reason for concern. The barrel stress is very low when compared to the spokes, but if more than .015" of material has been cut away by the contact, you should call John and get his opinion. I am not sure what CCW's barrel thickness is, but I am confident .015" is greater than 10% of the barrel wall.
Here is the filler plate on the rotor.
Here is the scraped area inside the wheel's barrel. The top of the pic is the outer edge of the wheel (for orientation) and you can just see the tape over the wheel weight. The scraped line(s) are obvious. Ignore the light reflection and rubber turds above the scraped lines. The left side is not as much. I only felt and heard the rubbing on left hand turns, but that doesn't mean on right hand turns it wasn't happenning. It just may have been less.
Here is the top of the caliper. No apparent scraping. Just the one black area.
Here is the bottom of the caliper. Besides the black marks-no apparent scraping. So what the heck is scraping??
Could it be the black areas??
Last edited by Dr.Ron; 08-18-2014 at 02:02 PM.
08-18-2014, 02:55 PM
#39
Former Vendor
See if the 3 white marks on top of the caliper line up with the grooves on the wheel.
BTW, it is hard to tell from pics but those grooves look pretty deep. I definitely wouldn't be mounting anything that takes elevated pressures to seat the bead (racing slick). Call John and send him the pics.
BTW, it is hard to tell from pics but those grooves look pretty deep. I definitely wouldn't be mounting anything that takes elevated pressures to seat the bead (racing slick). Call John and send him the pics.
08-18-2014, 06:25 PM
#40
Le Mans Master
Thread Starter
See if the 3 white marks on top of the caliper line up with the grooves on the wheel.
BTW, it is hard to tell from pics but those grooves look pretty deep. I definitely wouldn't be mounting anything that takes elevated pressures to seat the bead (racing slick). Call John and send him the pics.
BTW, it is hard to tell from pics but those grooves look pretty deep. I definitely wouldn't be mounting anything that takes elevated pressures to seat the bead (racing slick). Call John and send him the pics.
What do you mean about "not mounting anything....?"
The grooves are not very deep, more of the finish color removed, but what do you call pretty deep?
Ron
Last edited by Dr.Ron; 08-18-2014 at 06:28 PM.