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05 pepper white MCS modification project

Drivetrain (Cooper S) MINI Cooper S (R53) intakes, exhausts, pulleys, headers, throttle bodies, and any other modifications to the Cooper S drivetrain.
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  #1101  
Old 11-14-2018, 06:54 PM
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racing pads made of cheese

This was the 5th set of Wilwood BP-30 front pads. I installed them for a 2 day event at ORP, which was a new track for us and we ran in different direction each day. Mini trashed a set of brand new BFG G-Force Rival 1.5 tires. I should have flipped the pads after the first day of driving but I was too complacent. Only returned home that I discovered how badly the pads had wedged (like cheese cake slices) when I performed the post track day inspection.

This is the last set of BP-30 that I bought at bargain basement price on fleeBay. It appears that these are old school pad compound but not too abrasive on the rotor. They perform quite well on the track and even useable on the road, except they have very short life, or Desire is especially good at killing pads besides tires.









total mileage driven - 365 miles


 
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Old 11-14-2018, 07:32 PM
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whoops I flip them after every event, most are 2 day events but I've never had taper like that! I'm running st43 pads in mine now, very happy with them but they do need heat, I have to block my bumper ducts at NCCAR or they wont get hot enough and will put down a strange glaze on the rotor, and it takes a LOT of pedal pressure to stop the car.

I did pickup a set of those bp30 and I use them when we go up to tail of the dragon, I had the paint catch fire on one run after we stopped but otherwise they have worked well
 
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Old 11-15-2018, 09:48 AM
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The BP-30 pads are a less heat tolerant than Wilwood’s other race pads. What I have seen is that the wedging shows up more on a pad like the BP-30, I think, because it is at or beyond its upper temperature limits and that leading edge is being “melted” away.. This also may be the source of your braking vibration.. I saw both of these conditions at Watkins Glen using the Poly H pads and had none of it with the Hawk DTC60 pads. I attributed the vibration to “melted” pad deposits. It feels like a wrapped rotor, but it comes and goes and the rotor isn’t warped. The Poly H pads were fine at Lime Rock, as were the BP-30 pads. The DTC60 were way too aggressive for Palmer, probably never got up to temp and ate up a set of rotors. WGI is very hard on brakes through the whole track; LRP has one really hard braking zone and a few lighter ones. Palmer has no hard braking zones. I am coming to the realization that I need a different pad for each of these tracks... That said, I would suggest using the Poly B or H pads for that track that is eating up the BP-30 pads.

Yes, Hawk makes an 11.75” rotor in their DTC line of parts, that fits our Wilwood BBK. These are popular with the E30 and E36 race crowd around here. There is also a company called “Coleman” that supplies the stock car world who also makes a rotor (curved vane or straight) that fits both the 11.75” and 12.2” applications. The Coleman rotors are the least expensive of the three (including Wilwood). I have used all three. Can’t say one is better than the other based on my experience (which may be different than other’s opinions because of that stupid eLSD and poor cooling, all of whichl caused me to eat up rotors)
 
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Old 11-15-2018, 12:38 PM
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Originally Posted by Eddie07S View Post
The BP-30 pads are a less heat tolerant than Wilwood’s other race pads. What I have seen is that the wedging shows up more on a pad like the BP-30, I think, because it is at or beyond its upper temperature limits and that leading edge is being “melted” away.. This also may be the source of your braking vibration.. I saw both of these conditions at Watkins Glen using the Poly H pads and had none of it with the Hawk DTC60 pads. I attributed the vibration to “melted” pad deposits. It feels like a wrapped rotor, but it comes and goes and the rotor isn’t warped. The Poly H pads were fine at Lime Rock, as were the BP-30 pads. The DTC60 were way too aggressive for Palmer, probably never got up to temp and ate up a set of rotors. WGI is very hard on brakes through the whole track; LRP has one really hard braking zone and a few lighter ones. Palmer has no hard braking zones. I am coming to the realization that I need a different pad for each of these tracks... That said, I would suggest using the Poly B or H pads for that track that is eating up the BP-30 pads.

Yes, Hawk makes an 11.75” rotor in their DTC line of parts, that fits our Wilwood BBK. These are popular with the E30 and E36 race crowd around here. There is also a company called “Coleman” that supplies the stock car world who also makes a rotor (curved vane or straight) that fits both the 11.75” and 12.2” applications. The Coleman rotors are the least expensive of the three (including Wilwood). I have used all three. Can’t say one is better than the other based on my experience (which may be different than other’s opinions because of that stupid eLSD and poor cooling, all of whichl caused me to eat up rotors)
Thanks for sharing your insights.
I have little experience with various brake pads being used on track and this season has been a valuable learning experience. I bought 5 sets of the BP-30 as they were so cheap that was no brainer at the time. I didn't feel comfortable go spend over $100 for a set of front pads so I wanted them to tide me over a season or two. They have nice modulation and the right amount of grab for my driving skills. In retrospect having gone thru 5 set as well as used MINI OE, and Hawk I now have better idea what to expect. I think the BP-30 we bought at fire sale prices were obsoleted out for this reason. They just wear poorly. The fleeBay seller lives within a few miles of Wilwood is no coincident. He must be an employee or have connection to score a pallet full of BP-30 the company scrapped out of the inventory (the book) for next to nothing. For what's worth, I drove the newly installed BP-30 on the road only briefly trying to bed them in before track event, and I notice they wear easily so this suggests they simpler just wear out fast. Elevation temperated still likely accelerate their demise.

I have been reading up on the various race pads Miata track people use and I'd like to try out the ST series compound from Raybestos, as Mr. Blah reported good result with ST-43. Funny the company named Reybestos. I cannot shake off the thought that they used to use plenty of asbestos.

My brake induced front end shake is definitely not due to uneven brake pad compound transfer. There is no sign of deposit on the rotor. Also the tremor is triggered by hard braking at the end of a straight followed by a sweeping turn. It distinctly is a suspension or driveline vibration, without brake pedal pulsation nor shaky deceleration. I was hoping it is a wheel bearing, but I am resigning to more likely a front axle joint that is on the way out. A mildly worn CV joint can manifest all sorts of symptoms that are extremely elusive to find, and to make matter worst for FWD the outer joints have the toughest job of any drivetrain components. My Mini is just under 50k and the axles are original. I never abuse them nor slammed the suspension. I think turning them often close to the lock at low speed did the most damage in my case.
 

Last edited by pnwR53S; 11-15-2018 at 12:43 PM.
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Old 11-15-2018, 12:57 PM
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8" wide wheels

I took Desire out for a short test drive with the new 8" wheels and 225 45R15 tires. I want to make sure there is no hidden problems that I didn't anticipate. I also want to check out the steering feedback as these tires are 2 sizes wider than stock, and the 2.5 inch wider rim inevitably move the center line of the tire outboards. Going with wider tire typically tend to reduce steering feedback and the wheel may feel dead. If there is any I would say there is very little change from the 7" Konig that I have been using for the road. I know the true tests will require taking the car to the track and pulling max Gs in turns, hitting a few curbs while braking etc.

Here are a few photos including how much the tires protrude from the fender lips. These wheels being differ from the 949 Racing counterpart on the 34mm vs 25mm ET. Mr. Blah has 949 and his needing spacers reconciles well for these main difference.




rear


front







 
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Old 11-15-2018, 01:08 PM
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super fund

Super fund - not my budget for Desire's bottomless need for parts and consumables for track events.

So Raybestos indeed, like just about all other brake lining manufacturers used to use asbestos for friction material. Per wikipedia:


 
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Old 11-15-2018, 02:03 PM
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Originally Posted by pnwR53S View Post
Super fund - not my budget for Desire's bottomless need for parts and consumables for track events.

So Raybestos indeed, like just about all other brake lining manufacturers used to use asbestos for friction material. Per wikipedia:

Yup. Back in the day (and that wasn’t too long ago), if a school board want to ensure renovations to a school would get approved they would take air sample in the school near a street corner. It would likely show up as high asbestos in the air. That would trigger an asbestos abatement action and the renovations would go along for the ride. Of course the asbestos was car related, not school. But it worked for when work needed to get done. Then again, think of what all of us old farts have been breathing in our youth.
 
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Old 11-15-2018, 04:33 PM
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I might try afco 921-6640101 next, 55 $ a pop
 
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Old 11-15-2018, 07:37 PM
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Originally Posted by MrBlah View Post
I might try afco 921-6640101 next, 55 $ a pop
Good to know another alternative.
 
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Old 11-15-2018, 08:11 PM
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wheel hangers

I took Desire across town to get some live seafood and grocery shopping. I could tell she is obviously very thrilled with the shinny new wheels. She purred all the way despite we vigilantly negotiated the bad traffic. On the way home we dropped by the hardware store to pick up a couple of 12mm 1.5mm pitch bolts to make another set of wheel hangers to keep at home. The Konig wheels center bore is 73.1mm and I am resisting converting the lug bolts to studs as long as I can.

love, love this little car





I planned to use my old school craftsman's skills - just some elbow grease with a hack saw and the bench grinder. No CNC precision machined to 0.001" tolerance.

this is the first set I made last year
 

Last edited by pnwR53S; 11-15-2018 at 08:27 PM.
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Old 11-17-2018, 11:08 AM
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trade war is easy to win - and now we are paying the price

It seems that the import tariff of steel and AL has finally having impact on the consumers and vendors. This is just my observation of a few products. I was eager to grab the Konig Dial-In 15x9 from Amazon given the great price and free shipping. I have observed that the Konig Dial-In wheels in different size, finishes, has gone out of stock at Amazon. Checking other dealers also shows that they are nearly all sold out. Equally impacted are 949 Racing's most popular sizes, as well as Team Dynamics Pro Race 1.2. Out Motoring now outright stopped selling them entirely - blaming on the UK company.

949 6UL 15x8 is no longer available



note the red text that the company no longer sells Team Dynamics wheels - the UK company (Team Dynamics) is suffering from a double whammy - Brexit and US/China trade war

first this was 1 to 4 months out








then it is out fo stock indefinitely


If you are an importer of these products you would want to take a wait and see rather than passing on the cost to your customers. Many has front-loaded their inventory before the tariff took effect but these inventory has now depleted.

Oh, and yes. The Xiaomi Mi eScooter price that I bought from Amazon has jumped 20%.


 
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Old 11-19-2018, 10:29 AM
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With the crazing and cracking of the front rotors, do you think that slotted rotors would help with that? The slots should get more of the hot gasses out and possibly lower the temps on the rotors. Just a thought.
 
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Old 11-19-2018, 11:10 AM
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Originally Posted by Thought of a good one View Post
With the crazing and cracking of the front rotors, do you think that slotted rotors would help with that? The slots should get more of the hot gasses out and possibly lower the temps on the rotors. Just a thought.
I think drilled rotor, and less so slotted are full of hot air. I won't say the latter do nothing. I infer the benefit is less than measurable. Crazing and eventually cracking of rotors is facts of life of tracking your car, not unique to the Mini's. This happen even on Porsches that typically have big brakes. It is just that when you push your little econo square box to keep up with the big boys the problem becomes more acute.

The heat build up on the rotor can mostly reduced with ventilating the rotor to keep it cooler with effective air flow management to the vented rotors. However this alone is an insurmountable challenges with the tight wheel wells of the Mini and heavy front bias of FWD, and further aggravated by going with 15" wheels. Rotor temperature is a function of energy it has to absorb, and dissipate to air, from turning kinetic energy into thermal energy. When the thermal energy cannot be transferws out the temperature rises - as dictated by conservation of energy per the laws of thermodynamics. From what I read, cast iron rotor once reaches circa 1300 F the metallurgy structure of the iron is changed irreversibly. This is when the crazing first form. With each addition lap more crazing accumulated as well as the micro fractures grow bigger through all sort of reasons, and one obviously one is thermal cycling.

Without getting into all the trade offs of what are the best brake pads and rotors the take away is treat the brake components as major consumables as the tires.
 
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Old 11-19-2018, 12:57 PM
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Originally Posted by Thought of a good one View Post
With the crazing and cracking of the front rotors, do you think that slotted rotors would help with that? The slots should get more of the hot gasses out and possibly lower the temps on the rotors. Just a thought.
Originally Posted by pnwR53S View Post
I think drilled rotor, and less so slotted are full of hot air. I won't say the latter do nothing. I infer the benefit is less than measurable. Crazing and eventually cracking of rotors is facts of life of tracking your car, not unique to the Mini's. This happen even on Porsches that typically have big brakes. It is just that when you push your little econo square box to keep up with the big boys the problem becomes more acute.

The heat build up on the rotor can mostly reduced with ventilating the rotor to keep it cooler with effective air flow management to the vented rotors. However this alone is an insurmountable challenges with the tight wheel wells of the Mini and heavy front bias of FWD, and further aggravated by going with 15" wheels. Rotor temperature is a function of energy it has to absorb, and dissipate to air, from turning kinetic energy into thermal energy. When the thermal energy cannot be transferws out the temperature rises - as dictated by conservation of energy per the laws of thermodynamics. From what I read, cast iron rotor once reaches circa 1300 F the metallurgy structure of the iron is changed irreversibly. This is when the crazing first form. With each addition lap more crazing accumulated as well as the micro fractures grow bigger through all sort of reasons, and one obviously one is thermal cycling.

Without getting into all the trade offs of what are the best brake pads and rotors the take away is treat the brake components as major consumables as the tires.
The craze cracking and the ultimate crack failure is caused by the difference in temperature between the vane area of the rotor and the outside surface of the rotor. The outside surface heats up more than the inside resulting in compression of the steel on the outside surface and tension of the steel on the inside. This constant cycling of the surfaces into compression and tension causes fatigue to occur in that area. Because steel at elevated temperatures has a lower fatigue strength at higher temperatures than lower temperatures, the fatigue cracking (craze cracking) shows up first on the outside surface. The rotor, at some point, will crack through. It is a matter of when, not if. Cooling of the rotor and pads will help as this will reduce the peak temperature and the average temperature of the rotor so the steel will be perform with higher fatigue strength. This will result in the rotors lasting longer, but they will eventually crack.

So, yes, the rotors are a “consumable”.

Plain versus slotted versus cross-drilled. I had a change to talk to the owner and driver of the Jägermeister 962 Porsche about his brakes, which are cross-drilled. Thinking that this is a no-no and that the cross-drilled rotors on 911s and the like are just for show, I asked him why cross-drilled on his real race car. He said that the braking feel and performance is far superior with the cross-drilled than either the plain or slotted rotors. He said he has used slotted on the car but without the success of the cross-drilled. There is also a cooling aspect with cross-drilled with forced cooling. The 962 has a 4” hose from ducts on the leading edge of the car’s nose that is fitted to a form-fitting piece (looks like a hub cap, but on the inside of the rotor) that channels the air into the base of the vanes, pumping tons of air through the brakes on that car.. I did ask about the holes in the rotors causing cracking, to which he replied “all rotors crack”.

Now that I have most of my brake issues worked out, I am able to notice the more subtitle difference going on with braking on my car. I now notice that the titanium heat shield spacers that go in with the pads add a little flex to the system and that results in a softer feel to the brakes (I don’t like). I have recently gone back to slotted rotors and, like the Ti shield, there is a difference in the brake feel compared to the plain face rotors. However, unlike the Ti shields, I like the feel with the slotted rotors better (more solid). I can’t say that the slots add to the longevity of the rotors through. I can say the with the cooling and the correct pads, the rotors last longer and the wrong pads, alone, will eat up a rotor.
 
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Old 11-23-2018, 02:38 PM
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porsche also casts some of them with holes, supposedly they do not crack as quickly as the way drilled rotors do
 
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Old 11-23-2018, 03:25 PM
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Originally Posted by MrBlah View Post
porsche also casts some of them with holes, supposedly they do not crack as quickly as the way drilled rotors do
I had heard something like that. Castings will grow grains where it cools first, so the grains will go around the holes. Fatigue can be grain direction sensitive and the holes willl be stronger in fatigue. At least that is my thought about it.

If I can get back into doing track events next season, I do planned to get a set of rotors with cross drilled holes to compare to the slotted rotors I have. Coleman, who made my custom rotors, has their own drill pattern for their curved vane rotor castings.

One other thing about cross drilled rotors is the size of the holes. I tried a set of the MINI Gen I JCW drilled rotors. The problem that I ran into is the brake dust collected in the holes as the holes were too small to allow the dust to pass through them. This cased massive vibration as that brake dust smeared onto the rotor from each hole. It was a real mess. My friend ,with a Gen I JCW and a Real Brembo BBK, doesn’t have this issue with the Brembo cross drilled rotors. The difference is the MINI rotors have about 1/8th inch holes whereas the Brembos have about a 1/4th inch hole. The Porsches I have seen with cross drilled rotors all have holes that are about 1/4th inch.
 
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Old 12-06-2018, 11:58 AM
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pnrR53S - a compliment about your thread here:
https://www.northamericanmotoring.co...ml#post4435933
 
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Old 12-06-2018, 11:56 PM
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Old 12-07-2018, 04:56 AM
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Originally Posted by pnwR53S View Post
I took Desire across town to get some live seafood and grocery shopping. I could tell she is obviously very thrilled with the shinny new wheels. She purred all the way despite we vigilantly negotiated the bad traffic. On the way home we dropped by the hardware store to pick up a couple of 12mm 1.5mm pitch bolts to make another set of wheel hangers to keep at home. The Konig wheels center bore is 73.1mm and I am resisting converting the lug bolts to studs as long as I can.

love, love this little car





I planned to use my old school craftsman's skills - just some elbow grease with a hack saw and the bench grinder. No CNC precision machined to 0.001" tolerance.

this is the first set I made last year

Ahhhhhhh, .0001 not .001 for those really into CNC . . . . . . . .
 
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Old 12-08-2018, 08:10 AM
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Originally Posted by pnwR53S View Post
I took Desire across town to get some live seafood and grocery shopping. I could tell she is obviously very thrilled with the shinny new wheels. She purred all the way despite we vigilantly negotiated the bad traffic. On the way home we dropped by the hardware store to pick up a couple of 12mm 1.5mm pitch bolts to make another set of wheel hangers to keep at home. The Konig wheels center bore is 73.1mm and I am resisting converting the lug bolts to studs as long as I can.
Why wait to put in studs? Are you not running centering rings with the Konig wheels? Not sure why that would make a difference with switching to studs. My Wrangler has studs and no centering rings for the wheels I just got, but I may get some as I have a slight vibration that I think may be related to not having them.

I switched to studs on my MINI a while back and, after I did, I wished that I had done it sooner. I got the Turner ones and they are great, but a little expensive. Their bull-nose feature makes it possible to put the nuts on with a impact wrench, just like a real race car (I think Desire would like that...). But that bull-nose feature does take up a bit of what could be threaded length. As a result their 55mm long studs, that I have, are only good for a wheel with no spacer.



 

Last edited by Eddie07S; 12-08-2018 at 08:14 AM. Reason: edit and typo
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Old 12-08-2018, 01:54 PM
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Originally Posted by Eddie07S View Post
Why wait to put in studs? Are you not running centering rings with the Konig wheels? Not sure why that would make a difference with switching to studs. My Wrangler has studs and no centering rings for the wheels I just got, but I may get some as I have a slight vibration that I think may be related to not having them.

I switched to studs on my MINI a while back and, after I did, I wished that I had done it sooner. I got the Turner ones and they are great, but a little expensive. Their bull-nose feature makes it possible to put the nuts on with a impact wrench, just like a real race car (I think Desire would like that...). But that bull-nose feature does take up a bit of what could be threaded length. As a result their 55mm long studs, that I have, are only good for a wheel with no spacer.


Thanks for bringing this up. It must be my non-trusting personal quark. Where do I start?
  • Where were these studs made, and their purported quality? I trust the original OE bolts that came with Desire and I knew better never to let anyone else but me to torque these bolts, never with impact wrench but a old fashion hand torque with a torque wrench.
  • I infer the original OE bolts were made in Germany. If anything, I can discern by their appearance and the lack of wear on the threads.
  • I read too many horror stories with wheels came off the Minis on the track. To name just two, our friend at SpecR53 Mini blog and my Miniac track buddy that tracks with a $50k car both had wheel stud failure.
  • The typical cost for a set of these wheel studs and nuts run about $100. I would be almost OK if I know they are of adequate yield strength to withstand repetitive torque and re-torqued to circa 90 lb-ft (or ft-lb which mades no difference). My OE bolts are paid for and I trust them. Why spend $100 for the unknown and questionable quality fasteners when your life depends on them?
Lastly, for me I have read enough about hub vs lug (bolt or nut) centric. It is the most misunderstood subject on automotive forums. I am no ME, but this should be a very simple discussion for those with a bit of mechanical aptitude. If the wheel has conical bolt/nut recess it is bolt/nut centric and the hub is just there to facilitate wheel change. Hub centric wheels use normal bolts/nuts with flat flange that lack the conical interface. How can a plastic (or even a AL) hub ring center a 3000lb/4 dynamic weight on a wheel against the conical nuts/bolts?

Here is an excerpt from 949 Racing about their 6UL wheels:
  • No 6UL's are hub centric except our Spec Miata and Spec E30 specific 15x7
  • No wheel, including 6UL's "requires" hub centering rings if the wheels are made correctly
  • The purpose of a centering ring is to facilitate installation. Once the wheels are torqued, they are just along for the ride and neither support or transmit load.
 

Last edited by pnwR53S; 12-09-2018 at 08:11 AM.
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Old 12-08-2018, 06:07 PM
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Originally Posted by ThumpR52 View Post
Ahhhhhhh, .0001 not .001 for those really into CNC . . . . . . . .
No 0.0001" tolerance ambition here . My shaky hands and the constantly walking bench grinder can probably hold 0.01" tolerance on a good day .









Finally I broke the bank and invest in a real brass hammer when the price is right.

a one-pounder this is
 
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Old 12-09-2018, 08:39 AM
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Originally Posted by pnwR53S View Post
Thanks for bringing this up. It must be my non-trusting personal quark. Where do I start?
  • Where were these studs made, and their purported quality? I trust the original OE bolts that came with Desire and I knew better never to let anyone else but me to torque these bolts, never with impact wrench but a old fashion hand torque with a torque wrench.
  • I infer the original OE bolts were made in Germany. If anything, I can discern by their appearance and the lack of wear on the threads.
  • I read too many horror stories with wheels came off the Minis on the track. To name just two, our friend at SpecR53 Mini blog and my Miniac track buddy that tracks with a $50k car both had wheel stud failure.
  • The typical cost for a set of these wheel studs and nuts run about $100. I would be almost OK if I know they are of adequate yield strength to withstand repetitive torque and re-torqued to circa 90 lb-ft (or ft-lb which mades no difference). My OE bolts are paid for and I trust them. Why spend $100 for the unknown and questionable quality fasteners when your life depends on them?
All very valid points and much the same ones I struggled with. These are many of the reasons why I took so long to make the switch. I too have seen the broken studs and what can happen as a result, including a new m5 that lost its front left wheel in a high speed right hand turn because of broken wheel studs. Not only did he hit the guardrail hard, he flipped the car. He was OK, but the car was toast. An expensive mistake when he found one stud that had broke and only replaced that one. In hindsight that was an indicator that the other 4 studs were on the way out, which is what happened.

I chose Turner as these are the studs they use in their race cars and many of my questions are answered by their web page:
https://www.turnermotorsport.com/p-3...6-e9x/?pdk=AQE

These are not cheap, but, as you say, there are few things on your car that you trust your life to. I figure you get what you pay for. Turner’s studs will be about double of what others go for. I seem to remember that I also considered the studs that Way sells. I just liked the idea of the bull nose on the Turner studs and that their studs are “tested” on their race cars

The wheel bolts and studs are considered by many to be wear items. Every time they are loosened and retightened they go through a fatigue cycle and after “X” number of cycles they will develop cracks which will lead to failure. On that bases I have been told that we all should be considering replacing these (studs and bolts) periodically. I think I have heard something like every 2 years.

You are also very right in the need to use a torque wrench to tighten the studs/bolts and do it by hand. I cheat a bit by using my variable speed impact wrench to spin the nut up snug (not tight), just to save some time. It is also important to know how to properly use the torque wrrench. That is, to slowly approach the wrench’s set point and to not go any further. Moving the wrench too fast as well as going past the “click” can result in greatly overly torquing the bolt or stud.

Originally Posted by pnwR53S View Post
Lastly, for me I have read enough about hub vs lug (bolt or nut) centric. It is the most misunderstood subject on automotive forums. I am no ME, but this should be a very simple discussion for those with a bit of mechanical aptitude. If the wheel has conical bolt/nut recess it is bolt/nut centric and the hub is just there to facilitate wheel change. Hub centric wheels use normal bolts/nuts with flat flange that lack the conical interface. How can a plastic (or even a AL) hub ring center a 3000lb/4 dynamic weight on a wheel against the conical nuts/bolts?
My thought on the hub centric rings is that they facilitate centering of the wheel and this allows the conical bolts to better align the wheel. In industry, a while back, the design engineers of pressure vessels included matched pairs of spherical washer in the stud design of their closures. The thought was these would slide against each other while tightening the closure bolts and by doing so would compensate for any misalignment and reduce bending stresses in the bolts, which, in turn, reduces fatigue stresses. Nice thought, but it practice they found that the spherical washers would lock together as soon as any load was applied to them and they would actually be misaligned more than if they were not used at all. I have read posts on NAM here of people not using centering rings and the wheels having a bad vibration. The addition of centering rings seemed to have fixed the problem. From this I think it can be concluded the wheel was not being fully aligned by the bolts alone, as the addition of the centering ring cured the wheel vibration issue the person was having. I am guessing that when the wheel was being put on without the ring, it was getting locked in place before being fully centered by the bolt.

You are correct in saying that a plastic or aluminum ring can’t withstand the radial loads that a wheel sees. But by evidence of the wheels not having any issues of staying properly located without the rings, these rings actually see no load at all once the wheel bolts or studs-nuts are properly torqued. It is the stud load creating clamping forces between the wheel and hub along with the friction between the hub and wheel that withstands all of the radial loads that a wheel experiences. The concentric rings only facilitate alignment of the wheel so the bolts/studs-nuts can fully do their main job. That is, keeping the wheel clamped to the hub.
 
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Old 12-09-2018, 12:29 PM
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we agree to agree

The truth is we agree more than disagree on the matter of wheels, especially on how to properly mount, and most important, torque down a wheel.

It is amazing how quickly I managed to mangle my hub/lug centric discussion. I put the foot in the mouth incorrectly stated the load on the hub ring once the wheel fasteners are torqued to spec. Any load on them should just the tug of war due to tolerances between the hub and the tapered lug bores. It is the clamping force imparted by the 4 wheel bolts that hold the load of the car corner.

For a properly made wheel, it should be both hub and lug centric. I know it sounds contradictory. The reason is majority of, except rarely even in the high end shops, the wheel balancing machines relies on the center bore of the wheel to carry out dynamic balancing for the sake of expedience and low skill labor that is all too common these days.

here is a balancing machine (looks to be a Hunter model with Road Force balancing) that clamps the wheel with pins at the bolt holes instead relying on the hub center hole; credit MartijinGizmo post at Minitorque

I suspect this machine give you the option of using a wheel center hole or the 4 mounting holes. The latter is likely an optional accessory that most shops elect not to invest.

My track buddy's R53 wheel studs failed on track at high speed was catastrophic. He told me it lost a front wheel and caused extensive damage to the front end as well as the drivetrain (engine and transmission).

There is no question that Mini's 100mm x 4 hub design is very inadequate for track use. Adding spacers to the wheels only put additional strains onto the lug bolts/studs. One benefit of stud conversion is you save the wear and tear on the threads of the wheel hub, though I don't know if there is documented case of screw threads on the hub fail. One thing I dislike most stud conversion is the risk of scrapped knuckles when handwashing. The bullet nose ones by Turner does not have this problem. Truth be told, I tried to buy a complete set at ECS for just $0.79 each. Of course if it is too good to be true, it likely is not. The fire sale price is because there were only 6 left and I try to buy 16.

note that this is 95.5mm


I recently became the proud owner of a Ridgid cordless impact wrench for the cost of a good set of stud conversion . It obsoleted the HF Earthquake pneumatic counterpart. I only use it to undo the lug bolts. I do use it to speed up the installation but just set it to snug up the bolts (set to 1) before hand torquing them to spec, with the similar method you use - small increments in a X diagonal sequence with the wheel not bearing the weight.




Lastly the true hub centric wheels should have lug bolts or nuts that has flange and no tapered face, like the center one below.







Evidently real rallye wheels has press-in steel inserts rather than rely on the soft aluminum for the lug bolt/nut interface.
 

Last edited by pnwR53S; 12-09-2018 at 12:45 PM.
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Old 12-09-2018, 12:41 PM
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all pimped out interior

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