Having the air only going to the vanes and not blowing on the rotor face is very important to help mitigate rotor cracking. The Gen II S has those MINI provided brake ducts that blow air to the inside of the wheel. When I pulled the dust shield off with the thought that it would help with brake cooling, I found instead that they over-cooled the inside of the rotor as compared to the outside and the temperature differential exasperated the stress cracking on the outside face of the rotor. That one you show looks good in the pictures. Hopefully the scoops look as well made.

 

I totally agree with how they should work as you detailed. A set is on the way here.

 

I brought the pyrometer to the track this past weekend. I like the meter as soon as I tested it. It is simple and easy to use. Very low thermal mass probe that is ergonomically designed. It defaults to Celsius upon turning on each time. From the time you poke the probe tip into the rubber to the reading stabilize is about 3 seconds.

I wanted mainly to gather some data as I had yet to read up on the subject matter. I took three measurements on each tire starting from the front left going CW. The sequence has been what I have been using to check pressure and brake temperature. The three readings were outside, middle, and inside surface where rubber meets the road. I was rather surprised the inside and middle read higher than outside. One thing that I would change going forward is to start with inside and work out as the inside tends to be higher than outside. Reason is heat transfer is proportional to temperature gradience.

949 Racing has a great article on why and how to use a pyrometer. Of course being 949 Racing they assume you have a Miata rather than the fun wheel drive Mini.

As it was a preliminary test I didn't take the reading until after one or partial cool down lap, since I now know the front left outer ball joint boot was killed by radiant heat from the red hot rotor. In the future we will have the pit crew do this in the pit lane as soon as the driving talent docks.

Here are the readings from two sessions but not hot off the track immediately. The absolute values are less important than the relative values.




All these number are just preliminary tests. I didn't measure the tire pressure but they are my typical pressure that I have been using. Note that the middle is the highest, the inside next, and the outside lowest. Each set of reading took no more than a minute or so and I call out the reading into a sound recorder phone app. With this method, there is no reason to wish that the pyrometer has built in fancy feature for logging multiple readings for each tire. It would just be more time consuming and chances for error. I highly recommend this pyrometer which happens to be the most reasonably priced one out there.

The numbers look good to me as the front wheels doing triple duty.

 

Dissatisfied with the external microphone for the GoPro placement I moved it to the storage net behind the passenger seat back hoping to lessen the wind noise and may be pick up more of the exhaust sound. It didn't work well there and the sounds that I want to capture is too muffled. Next time I would experiment by moving it up onto the dash center hoping to pick up more engine sound and less wind noise and rattles.

In this past weekend I concentrate to improve my time, the lines, but not overdriving. Video like this is helpful for me to review my own driving and I can identify many places that I can do better. For example where I might be able to have more throttle, lift up less, or hold more throttle while left foot braking. My lines have been quite consistent. There were few instances that I shaved too close for comfort. I also remember to patiently allow the tires to warm up and gradually increase the speed during the first session in the morning and after lunch. I also been employing more overlapping of left foot brake and right foot throttle application in turns that are applicable.

There were only 6 cars that day so most of the time we have the track all to ourself. We ran CCW on this second day at Oregon Raceway Park.

 

I am getting a bit tired with the Harry's Laptimer app. It may be just the iPhone and usual poor cellular coverage at this remote track. Often the app the lap timer does not auto start. The other thing that I hate the most about the app is each time you switch app and back, it may lost its continuity and you have to start from scratch, say OK to the annoying legal disclaimer and load the god damned track again.

I am considering the AiM Solo II DL. The DL is a data logger and should support R53 Mini's can bus interface so it can pull realtime engine parameter directly from the CAN bus (at the tach harness). My Miniac track buddy just has his shop installed the Solo II DL with the optional Smarty Cam though I have not seen the installation. Also he has aftermarket ECU so what work in his case does not necessarily would in my stock ECU car.




The installation is pretty simple. This install video is for a BMW M3 circa 2004 which is the same era with our Mini. The main difference is we would tap into the CAN bus at the tachometer harness.



available channels




One of the side benefit is the DL LEDs can be set up as shift light. Of course the most powerful features are the ability to perform detail performance analysis post driving on a PC or iPhone.

 

A lot of great info in your last few posts. I’ll be interested to see the brake ducts kit you get.

Your disappointment with Harry’s is interesting. Your’s works differently than mine. Mine always retains the track and I never have to go through the startup screen, unless I shut it down. Of course, now that I have said that, it will probably now do what yours is doing (I’ll find out tomorrow) ....

The thing that I have not liked about Harry’s is only going though the OBDII port. It tends to be slow and there is info that you can’t get. On the MINI, braking info is one thing that is a must but can’t get. I have heard about the CAN bus but knew nothing about it and figured it was something that was beyond me. But, maybe I should have looked into it more, as with your quick description it seems pretty simple. AIM is one that seems to have a good product. It will be interesting to see what you come up with and how much out of that CAN list of things you can actually read.

 

The truth is I have a lot of respect for Harry's and the app served me well at PIR and our early journey into track driving. I paid for the Gran Prix version. The problems are more has to do with if you want to play, you'd got to pay, plus the OBD data from these earlier cars are just far less than rear time. Additionally, apps like this relies on the "GPS" of smartphones which aren't as smart as most thinks. Smartphone's so called GPS should be more accurately referred to as pseudo-GPS. They work damn well in metropolitan because they rely on cellular towers as well as known wifi location to augment the rather poor GPS geolocation. I believe they only use one constellation, and only if it can "sees" at least three satellites. So there are a lot of interpolations going on that we casual users that ignorance is bliss. At ORP some Harry's videos have the G force update like once every 2 seconds. It might be the iPhone needed to be rebooted because of rough apps' memory leak.

We should be very grateful that we are not relying on LORAN, or worst inertial guidance system like in aviation before GPS for our geolocation fixing.

Out at ORP in the middle of nowhere all these pyramids collapse and the limitation of the "smartphones" lay bare. I don't blame Harry's for poor car parameters processing via the OBD port. Our earlier car has crappy OBD data rate that is "we get there when we get there" parameter update. I invested in BT and WIFI ODB dongles and only to realize just money down the toilet - with no fault of Harry's. ODB are not intended for providing close to realtime car parameters.

On the parameter list that AiM shown for Mini, I would be a real food to think all are available. Too good to be true and do not pass the sanity test. I know what I can expect. I would be very happy with just RPM, throttle position, brake switch, clutch switch (I am damn sure there is no clutch switch), and wheel speed sensors (and I hope they prioritize GPS over the speed or wheel speed sensors for MPH). I don't want garbage in garbage out data processing.

I suspect our differ experience with the need to re-agree to the disclaimer and reload track has to do with background app processing of our phones, as well as the poor cellular coverage at ORP. Harry's is a nice app for occasion track driving. I would not take it's lap time to the bank nor assume the G-force reported is accurate.

As for the AiM Solo 2 GL, I want to be able to analysis my driving with its data logging. I was initially dissonant seeing the price difference of the Solo 2 and the Solo 2 GL which mainly differ just the added memory capacity and firmware. The ability to utilize one column of LEDs for used as shift light make the investment more palatable. I will hold off buying the Smarty Cam though as $1000 camera is clearly a lot of gravy these day when you can get a high end sports camera for a couple hundred dollars.

 

I was glancing through Solo 2 DL specifications and saw it has gyrometer as well as magnetometer sensors inside. They perplexed me as to their uses. Well this video answer the former that is the gyroscope sensor. It is for lean angle for bikes. Good, I can use it to analyze my relatively soft Swift spring suspension which I wonder if they are too soft for my applications. Still the magnetometer sensor leave me still perplexed for its rolls and purposes.


Here is a short shift light video also:

 

I quickly dropped the smart phone GPS and added the Dual Bluetooth antenna. This also increases the sample rate to 4 - 5 per sec. It makes the Harry’s data much better. But, as you noted the OBD port data is not very good. So, I get limited use out of it.

I’m headed out to LRP today for an event tomorrow. I’ll check out the AIM videos later...

 

I have a Dual BT GPS also but too lazy to set it up as it is PITA may be just the iPhone.

I unwittingly signed up for a track event tomorrow before I discovered the left axle boot puncture. It will be a wet track so we will mostly likely driving at parade speed, especially behind the Mustangs, Cameros, AMGs, M3/M5, Porsches, and Vettes holding up Desire on the track.

 

We have been running with parts logistics more like hand to mouth situation. Just too much stress hoping the supply would arrive in time for the next event. We decided to institute a prefetch pipeline supply logistics to ease some anxiety. The two most important areas are tires and brakes. Like they says when push comes to shove it is the rubbers that meet the road that counts. Having two sets of rims is good, three would be better. With the set of spare ready we can also be able to utilize these wearables closer to the last good drop.


these Nitto NT01's were mounted only 4 track days ago



now they are like slicks and Desire likes it



thanks to our prefetch pipeline supply, the set of Toyo R888R is waiting in the wings; we bought this set to the event last weekend but didn't need it as we were squeezing out the last good drop off the Nitto's



Desire is sliding towards becoming an all track car; this would be her first set of semi-slick; why 3, you ask? it is a long story and hopefully one more will arrive soon


we were hoping for good to the last drop utilization of the consumables and our wish was granted



hard to squeeze more out of these ST-41s; they would be dissected to see what they are made of



happiness is a set of new Raybestos and spanking new rotors fitted into the Rose Gold Limited Edition Wilwood calipers

 

We had more than our share of challenges with the usual consumables. We had a slow leak on one tire. We had multiple cracks on the front rotors and we are running on empty with the set of Raybestos ST-41's that is on borrowed time but still we managed, and in both days we were the last men (we would count Desire as man with her valiant can do attitude , sound sexist but we are not as we are the Spartans ) standing.

We tired very hard to hold off the big bad BMW purpose-built track car but a mis-shift the big bad wolf pounced. Desire put up a good fight until the miss-shift (@5:02) in this last session on the last day. Only two of us were still playing, and we by then had a leaky tire, cracked front rotors, and paper thin brake lining remained.


Undeniably the BMW is a faster car and the driver has much more experience with this track and track driving experience. This was our forth event on this track. I am very pleased with Desire given her very streetable modest modification list. We can see OS Giken clutch in the horizon. This track is very hard on the clutch, brakes, and tires; and we say, in unison, F*** the engine mods because that are the last things we need.

 

A lot of newbies to the track think that the first mod they should do, absolutely need to have, must make is a boost in power! The heck with brakes, or tires. No self-preservation there.

I am continually amazed at people who think an upgraded street pad is adequate for the track. Yesterday I felt it necessary to explain to an experienced driver that a Hawk HPS pad isn’t adequate for the track and that was why he was having brake issues. I think that the only thing that gave me some amount of credibility was that the classroom instructor said that I plenty of experience with brakes and that he personally knew that as has had to help me out of my own brake issues.

I ran the BP30s for a 3 rd day. They seem to get gummy and leave rotor deposits if they don’t get hot enough (we had rain part of the day). When they got more heavily used they were fine. It may be that they have a moderate wide temp band. Like the three bears - not too hot, not too cold...

I had a couple of more thoughts about your wheel bolt loosening issue...
People underestimate the importance and contribution of the rear brakes for slowing down a MINI. Just to throw out some made up numbers - Say the rear brakes are only doing 20% of the total braking (because of race pads up front and street pads in the back) and you increase the rear braking load by 50% by putting race pads in back there, then you decrease the front brake load by 15%. I run DTC 60 pads in the rear and I have no issues with lock up or squirreliness. And it did help with the front brakes. This would benefit both the brakes and the bolts by keeping everything cooler.

I re-thought the Porsche stud switch. That actually may be a good idea. Not because they are “Porsche” studs; any studs will do. My thought is that heati is getting into the threaded area on in the hub, and this is causing the hub threads to expand. The bolts hang out in the air on the other side of the wheel which means they run cooler, including where they are threaded into the hub. This causes a difference in expansion between the two and might be causing the bolts to loose preload (same as using a torch to help loosen a rusty bolt). If you put studs in (pressed in ones or Loctight-ed ones), then the load bearing threads will be in a cooler part of the assembly. This would help to keep them from loosening from heat. That is my theory and I’m sticking too it...

 

I have huge brake ducts, at nccar (easy on brakes) I have to block them off or the bp30 will lay down pad material on the rotors and lose a lot of torque. They never act up on the street with the ducts. This track has a 1/2 mile straight and the rest is light dabs into the brakes.

Once I realized what was happening one session with the ducts blocked fixed the rotors

 

Thanks Eddie and Mr. Blah for your posts. Your insights and experiences are invaluable to me and appreciate your posts. I have gathered a lot of new data points and tested fitted the brake duct shield and scrutinized many challenges. We certainly would have some healthy discussion and experience sharing for many posts to come. First thing first. It is passed 5 PM and I just have a chance to grab a first bite to eat for the day. Just finished the inevitable post-track event maintenance and swapped out the bad left front axle.

We signed up the last minute for TNiA here at our PIR home track for yesterday late afternoon. Desire is the little piggy that left her peers here in the local swine sty to see the world and she has faced challenges at Oregon Raceway Park and thought she had learned something. She have driven there 6 days now with 3 CW and 3 CWW. We thought we would come back to the home track is see if she really learnt a few things as she thinks she had.

We signed up for the Advanced group. Our first session didn't start until almost 5:45 pm. The forecast was not encouraging. Showers likely, mainly after 5pm.




Showers likely, mainly after 5pm. So to be safe I changed the Nitto NT01 that *** semi-slick to the brand new Toyo R888R, and installed a set of $35 apiece cheap Wilwood rotors and a set of Raybestos ST-45 pads. We didn't take the trailer nor the motorhome. We loaded up Desire with the set of very worn Nittos and headed to PIR. Our expectation is with so much learning from ORP we want to see how well we fare at this small flat track.




this is the most cargo Desire'd ever haul and she was not too happy but the thought of showing off at PIR kept her from complaining



yep, two exotics



there were 3 Civic Type R's all counted






quite a few S2000's



good for the Ferrari owner that he signed up in the novice group; more on the McLaren to come



















the McLaren driver donning a Bondurant racing school T shirt drove in the intermediate group





desire lined up behind this red Gulf R; behind her is a S2000


a nice and rare Celica ST back when Toyota wasn't totally building just beige cars


some of these much higher HP cars sure intimidated Desire


this is an Audi S3 RS R - lots of Rs must be very fast


the last session we were the first car out, and the Vett never caught up to us


Desire ran ~72 miles and empty close to one full tank of fuel; we barely made it back home without being stranded

We had a few showers before and during the sessions. Two hours before the run our team decided to take a chance and swapped in the Nitto NT01 *** slicks as we really want to use up the last drop of the rubber left. We thought we might just get lucky and have a dry afternoon despite the not so promising forecast. It would proved our wish was misplaced but we decided to not change the tires. We wanted to learn something and our thought was as long as it does not rain hard that the tires need to channel water we should be fine. It would prove that this thinking was correct.

We ran three sessions. We had too much tire pressure in the first session and the tires stayed quite cold. We lower the tire pressure for the second and third sessions. We also check the lug bolt torque after every session and they didn't work loose. We applied what we learnt from driving at ORP. The new brakes worked really well and we were braking ever later at the end of the two long straights. I used plenty of left foot braking, and often modulated the throttle in conjunction to left foot trail braking. I can now brake with the left foot even on those after a short straight and requires very hard braking like turn 7 at PIR. We were cautious not to be cocky and overdrive in this seemingly easier and flat track.

In all three sessions we had light showers and wet track but never too wet. In total there were about 90 cars spread out in three run groups, with the least cars in the advanced group. We were very happy to see our friends and acquaintances including a neighbor with his Miata.

 

The rain clouds moved in around 4pm and we were biting our nails. We kept thinking as long as it does not rain hard and causing enough wetness that the tires need to channel water we should be fine, but that is just a rationale. Can you take rationale to the banks?


Desire and her comic huge amount of wheel gaps; but don't judge the book by the cover


While it was our first day of the season driving this track, we did pretty well. We beat our best time last season in our first session with less than optimum tire pressures. In our the last session we bested our last season's best by over a second. Our average times were more consistent than last season's. In three sessions the only faster cars were the Gulf R and the Honda Civic Type R. There were 3 Vettes and a couple of BMW M cars. A few GTIs, and a couple of racy Audi's including a TT, two S2000, a few Miata's, a Cayman, a Viper, and the rest we couldn't tell from the shrinking images in the rear view mirror.

 

Sounds like you had a day like mine and, like mine, it was filled with fun.

 

I have been keeping this resource to myself, mostly because I was unsure if it is just one of those intermediate stepping stones and soon I would be over it any never look back. I only begun driving on tracks in earnest less than 2 years ago. I was tempted to buy a few books on high performance driving but luckily for me I came across this site and found there are much for me to test out and learn, and I didn't buy a single book. Let me just say for most of the skills that I acquired in life, I leant most by just do it and leant from mistakes myself. Performance driving is hardly any different. All counted, I had instructors sitting next to me 4 sessions. The experience were mixed, especially when you are driving a front wheel drive. A lot of folks thinks that FWD are just plain wrong but I like to be able to drive any cars fast no matter what configuration they are. Randy Pobst's favorite car is a Volvo FWD and if FWD is good enough for Randy I am fine with being handicapped.

I have been tempted to buy one of those countless advanced driving books but in the end I was too cheap to do so. Instead I have been keeping this to myself more the less. This site Race & Track Driving have helped me in my track driving more than anything else. Only today, after spending a lot of time trying to find the site again, that I dig a little deeper of who the person is behind this writings. Evidently it is a MX5 driver Oleg Pudeyev.

If you are inexperienced as I was in 2007 and want to learn fast, I highly recommend reading his articles, according to your lever of performance driving.

I leant to drive ORP all by myself, and never did I have an instructor sitting next to me. It may be just how I learn and I tend to turn to myself and try to be analytical. With patience and care I learnt the countless subtleties of this track. The cones did help but often the cones were not placed correctly.

 

Randy Pobst writes a monthly, 2 page article for the SCCA magazine. I alway look forward to reading these as he does really well at picking a relevant topic and digesting it down to the salient points in those 2 pages. At times I found that he doesn’t follow the conventional wisdom on driving. That must be due to that Volvo driving he did...

 

I thought you might be interested in seeing this post on nether Brake Duct thread...
https://www.northamericanmotoring.co...ml#post4470646

 

Since started really tracking in Jun 2017 I started with stock pads, and that was fine for a while. Soon I I was driving with Hawk HP+ and that was fine for a while. It is all about with improved skills we are all become harder on the brakes. All 5 sets of BP-30s simply didn't last for me. They worn out in 2 days at ORP. They might have lasted another 1/2 day had I not forgot to flip them on fifth set after one day.

I don't know what to make of why you need to blocking the ducts on track. Were the temperature simply too cold with the ducts? They don't seem to drop off that fast/much at the low ambient end.



I agree whole heartedly that rear brakes are just as important. I have a set of Cobalt XR5 in the rear that I acquired for a song. They are not that aggressive though and I will want something that compliments the ST-45 this time. Racing pads on stock calipers are crazy expensive and most listed for ~$200 a set for the rear. All cars will get squirrelly if you brake hard enough at the end of a long straight or worst going down hill. My Porsche got pretty upset when I brake too late and it has no shortage of brakes.




At PIR I met with this M5 owner that I acquainted from last year. One day at PIR he was the most unhappy M car driver that I've seen. He said he didn't have enough brakes because he has stock brake and road tires. He left after 1 session.

This time I thought good, he came prepared and sure enough his spirit was high. I asked what he did to get the car track ready? He put on better tires just for the track and I asked what about the pads? He mumbled something about he order them, but still have the stock pads.

 

Our talk of the potential cause of the lug coming loose may due to excessive heat got me very worry. I most worry about the Wilwood AL rotor hat to the rotor bolts working themselves loose. They are augmented by red Loctite per installation instruction and still I worry that the temperature exceeds ~500F of the red Loctite. I braced for what I may find when swapping out the cracked front rotors and replace them with $35 straight vane garden Wilwood.

To my relief none of the fasteners were loose. They required considerable torque to undo and I could tell the red Loctite was not compromised by temperature.




I had a hard time to torque the Torx bolts for the rotor hats to 25 ft-lb. Even my Made in USA Torx socket bit bent to hell. I know you can get a kit with normal hex bolt head from Wilwood for used with safety wires. For now I reused the Torx bolts with red Loctite.






I am quite happy with this HF torque gauge; it keeps me sane for not worry about the HF clicker torque wrenches being way off





As a post mortem I have been suspecting that the new Konig wheels might had contributed to the lug bolts coming loose. I examined this new set and there is no pain on the countersink. However they are quite smooth, and is possible have a coat of clear coat on it. Eddie has 14mm lugs on R56 but we mere mortals with R53 have to live with 12mm. I think 12mm is simply too weak especially with 4x100mm lug pattern. It does not deliver enough clamping force to hold the Wilwood rotor hat from turning. The other factor is the rotor hat lug holes are designed for used with 14mm lugs.

When I need to replace the front hubs I will want to use the one for late R52s which has 14mm lug holes. My research suggests they are most likely just R56 hubs.

 

To prepare for PIR I swapped out the badly cracked Wilwood Spec 37 directional rotors with much cheaper straight vane ones that cost 1/4 the price. I wanted to try the cheaper rotors at least until I get the front brake ventilation sorted out - which will be a challenging project to get it done right.

I have been plagued by inadequate clamping force by the 12mm lug bolts since day one of the Wilwood BBK. The Torx countersink bolt that serves as a installation aid has been bending to hell and I swapped them with the ones from the rear. I have not replace them thinking that new ones will just get bent the same so why bother as long as the head has not sheared off.


left front rotor; you can see the rotor has rotated WRT the hub due to the sloppy 14mm lug holes with 12mm lug bolts



the right front rotor; same problem with inadequate clamping force



left front Spec 37 rotor with 2 bad cracks



right front Spec 37 rotor has 3 cracks

the most perverse thing about these $130 "Spec 37" rotors is the packaging it come in are just plain ****! badly design packaging like fit for a pizza that got destroyed in shipping





to the contrary the packaging for the cheap utility $35 straight vane rotor has excellent packaging





even the plastic bag is thicker and heat seamed





I ran 3 sessions at PIR with these cheap rotors and so far they held up quite well. I am going to monitor them closely in the next event at ORP (with no brake ducts).

 

By now I have little doubt the leading cause of my premature cracked rotors is extreme temperature differential between the inside rotor face and the outside rotor face; or that the outside rotor face simply starved of cooling while the inside one does not.

Both rotors has multiple cracks on the outside faces but none on the inside faces. I too reason as Eddie has written that the right way to cool the brakes is to direct the air current only to the inside of the rotor where the vanes intake is. This is the only way to help dissipate the heat on the outer rotor face. Designing and installing brake ducting on our Mini is easier said than done. I have not attempt but I have inspected and gave the matter a lot of thought given the constraints that I observed in the front wheel well.

I received the AAF front brake duct brackets and I am very pleased of how well design and made they are. The biggest challenge for me is how best to utilize them. I defer ordering the duct hose knowing that I may likely take a less than conventional route. These silicone hoses are not cheap.

 

I performed the post track event inspection on Desire. I swapped the racing pads and replaced them with the lowly Wilwood BP10 for safe street driving. I wanted to test out these Raybestos ST-45 pads and utility Wilwood straight vane rotors (I know Mr. Blah had) for myself. I knew they should hold up fine at PIR but at ORP the jury is still out. They are cheap and I can afford to replace them after 3 days of use, I thought; until I get my ducks ducts in order.


swapping in the Wilwood BP10 street pads and the Raybestos ST-45 out during post-track day maintenance and inspection



these ST-45 saw three short session at PIR



the left front rotors looks fine though some modest wear



the left front pads do not show excessive wear but some wedging that is inevitable



the right front rotor looks similar to the left front



the right front ST-45 looks similar to the left front



the other side of the pads