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The temp paint will pick up the near-peak temperatures of the rotors during braking. The brakes will cool several hundreds of degrees before you reach the grid and stop to take a temperature measurements.
I have some of that temperature changing paint and have seen temperatures in the 1100 to 1300 deg range. I am not sure what you will do with data that is 300 to 400 deg below that. Also, the temp paint was $60-$70, which is probably less that a IR thermometer that can read into the 1000s of degrees. OK - you posted before I got mine posted. I stand corrected on the price of an IR thermometer..
Last edited by Eddie07S; 06-19-2018 at 07:33 PM.
Reason: Edit for above post.
OK. I concede my plan is flawed. I agree that the peak is what matter, though a relative long peak. I went to AP racing and can no longer find the three bottle kit they sold. But Racing Shopper has a similar kit. I read that the all-in-one can be hard to read.
I agree, the all in one is hard to read and it is about +/- 100 deg. So, not real granulated, either. It is not like getting a recorded digital reading at 10 or 20 hz. The best that I found it useful for was to ensure my brake pads were rated for above what I was reading.
Try to avoid a bad day because the wheel locks up. I don't know if there is always time to catch it before the crack becomes a fatal hazard. I read some put their car into a wall because of it.
I just received a few more photos from our track team photographer for the Jun 8 track event. Not much to show for really. I was hoping to see one with the rear inside wheel in the air but the track was too slippery for that.
Try to avoid a bad day because the wheel locks up. I don't know if there is always time to catch it before the crack becomes a fatal hazard. I read some put their car into a wall because of it.
can you repair this?
Whooow...That’s a pretty good crack.
I have seen worse. It is interesting that there is very little craze cracking on that one. Likely the flaw started down at the mounting bolt hole and worked its way up. But that is a discussion for another time.
My experience from having cracked and seen many a Wilwood style rotors that have cracked, is that they tend to crack in a very “kind” fashion. That is, they will start to craze crack. While it may be all over the surface, it is the width and depth of the cracks that you look for. Once you see some depth or “measurable” width, then they are almost done. When they do crack through a face, they feel like a warped rotor. If you have been checking them, you should expect this. They tend to crack in a straight line and they tend to crack on the outside before the inside (which means they stay together and they will fell warped). All of this means that you should get a warning that they have cracked and that should be before they get so bad they put you in the wall.
I run with a group that also race E30 and E36 BMWs and they run the same rotor style, and they crack them. I say “style” because these rotors are made by Wilwood, Hawk and Coleman Racing (that I know of). All are different castings and all have cracked the same way; that is “kindly”. Everyone at that level carries a spare set of rotors. Usually they change out the rotors when the craze cracking gets “heavy” and those become the spares. I have had problems where I have had to used some of those spares and have gotten 2 more days out of them...
I did see a Wilwood rotor that had cracked and lost a silver dollar size chunk. The guy drove 4 hrs home on it...
I don’t know anyone who has correlated brake temp with a prediction of when the brakes rotors will crack. Everyone just watches the rotors closely and changes them when the craze cracking gets to be “heavy”. Not sure if I can give a measurement to go by, but I get concerned when the crack depths get to be about a quarter of the way through. Your picture shows light craze cracking, which is the point I would start watching the rotors closely. On my car, I would expect another 4 or 5 days on that rotor.
I also got rid of the Wilwood Torx screws as I have had the heads pop off (I am careful of with torquing them) during use. I replaced them with Grade 8 bolts and carry a spare set of those too. Actually, when I go to the track I carry a spare set of: piston seals
Rotors
Hats
Bolts
SS brake lines
Brake fluid
Plugs for the lines
On a 2 or 3 day event, almost anything can happen.
Whooow...That’s a pretty good crack.
I have seen worse. It is interesting that there is very little craze cracking on that one. Likely the flaw started down at the mounting bolt hole and worked its way up. But that is a discussion for another time.
My experience from having cracked and seen many a Wilwood style rotors that have cracked, is that they tend to crack in a very “kind” fashion. That is, they will start to craze crack. While it may be all over the surface, it is the width and depth of the cracks that you look for. Once you see some depth or “measurable” width, then they are almost done. When they do crack through a face, they feel like a warped rotor. If you have been checking them, you should expect this. They tend to crack in a straight line and they tend to crack on the outside before the inside (which means they stay together and they will fell warped). All of this means that you should get a warning that they have cracked and that should be before they get so bad they put you in the wall.
I run with a group that also race E30 and E36 BMWs and they run the same rotor style, and they crack them. I say “style” because these rotors are made by Wilwood, Hawk and Coleman Racing (that I know of). All are different castings and all have cracked the same way; that is “kindly”. Everyone at that level carries a spare set of rotors. Usually they change out the rotors when the craze cracking gets “heavy” and those become the spares. I have had problems where I have had to used some of those spares and have gotten 2 more days out of them...
I did see a Wilwood rotor that had cracked and lost a silver dollar size chunk. The guy drove 4 hrs home on it...
I don’t know anyone who has correlated brake temp with a prediction of when the brakes rotors will crack. Everyone just watches the rotors closely and changes them when the craze cracking gets to be “heavy”. Not sure if I can give a measurement to go by, but I get concerned when the crack depths get to be about a quarter of the way through. Your picture shows light craze cracking, which is the point I would start watching the rotors closely. On my car, I would expect another 4 or 5 days on that rotor.
I also got rid of the Wilwood Torx screws as I have had the heads pop off (I am careful of with torquing them) during use. I replaced them with Grade 8 bolts and carry a spare set of those too. Actually, when I go to the track I carry a spare set of: piston seals
Rotors
Hats
Bolts
SS brake lines
Brake fluid
Plugs for the lines
On a 2 or 3 day event, almost anything can happen.
I have been browsing the WWW for cracked rotors on iron disc, and I agree there is no simple way to predict when the crack will set in except to be extremely vigilant about your brakes as with your wheels and suspension bits. Drilled rotors are definitely to be avoided. There is no evidence that slotted make any difference except for arguing other benefits.
I started out travel very light to the track but I am beginning to bring more excess baggages. Still I am not ready to bring these spare parts until I get a AL light weight trailer. p.s. I looked into getting a spare set of Wilwood rotor hat, and found that the price is ridiculous - $135/ea list plus $15/set of fasteners. It should be no surprise as if you build Mini from parts it will cost a million $.
An eye opener for me is to see that the LF brake works much harder than all others for a CW track PIR is. I found more crazing on that rotor as well as faster pad wear.
That is just a random cracked rotor photo I scouted on the web. It looks like a 911 left rear.
It is becoming a ritual or habit. I did a early burrito run which serves many purposes. Prepare easi track side meal for my crew and Mini. Mini's is most expensive as it has hog's veracious appetite. The short trip also gives a last minute road worthiness check that most, if not all is well.
People joke that I could pull an engine and rebuild it with what I carry. Not quite but I do put a lot into my MINI. A full set of tools, jack, air pump, jumper cables, chair, table, sun shade, 2 - 2.5 gal gas cans and 4 spare tires/wheels, in addition to the brake stuff, camera stuff, food, helmet, harness and a box of miscellaneous things (oil, brake fluid, spare brake pads, etc). Oh, where will it ever end...
It is becoming a ritual or habit. I did a early burrito run which serves many purposes. Prepare easi track side meal for my crew and Mini. Mini's is most expensive as it has hog's veracious appetite. The short trip also gives a last minute road worthiness check that most, if not all is well.
I carry all that stuff too, and an ezup, along with spare belts for 15% and 17% cars, I have sold a few of these to get other mini's going again
if I use a tool to fix the car at home, I make sure I have that tool in the trailer too so I do not forget it. I try to make sure those tools all stay in the trailer, and it's cheap stuff mostly harbor freight in case it goes missing
There are so many ways to get the amenities to the track.
Desire's idea is not to tow one, but to ride in one; like this one worth more than Mini and its spare parts combined. Too bad it is not even available on the left coast unless you want to pay hefty shipping. When a used one comes up on sale they don't last for a couple of days.
At least Desire is not dreaming of an enclosed trailer, which just about every one has at the local race days.
We had a 1.5 burrito day today. We lucked out weather wise as it was forecast to be near 80 a week ago. We ended up with the day time temperature not exceeding 70F. Track event is measured by units of burrito. One full track day is 1 burrito. Track Night in America is 1/2 burrito.
our track team were the first to arrive
After four 20 minute sessions Mini was hungry; aka running on empty.
Mini was starving after four 20 minute sessions
106.7 miles to a tank; and there are like 6 miles are not track driving
13.5 gallons
Doing the math, Mini got may be 7.7 MPG on the track. And yes, this is just a 15% pulley, no tune, and no cam. In all Mini traveled 160 miles flat out, and consumed more than one and a half tank of premium petrol.
I beat my last best lap time by 1.70 s today. My best before today was 1:37.82. Today's best was 1:36.12. I learnt to be gentler and smoother on the brakes, as well as picking up time here and there at many turns that I left on the table. I also braking consistently later at the end of the straights.
When I first installed the Wilwood the much stronger brake torque threw off my heel and toe as the brake pedal is that much more touchy. It has taken a few track days to adjust to it, by consciously not to jerk the brake when on the supercharged Mini you have to blip the throttle much harder and longer than an atmospheric engine.
Last edited by pnwR53S; 06-22-2018 at 06:06 PM.
Reason: corrected minitue:second.hundreds of second punctuations
The numerous cones are misleading. They are there for the pre-grid. It was a fun fun HPDE event.
While we were having fun, on the other side of the city a single lightning strike took out 3 giant trees. They are over 150 yards apart. All three trees instantly exploded from the awesome energy. The lone tree up on the hill caught fire and the top section fell off with a near miss of the house.
Had that lightning struck a human body, there would be nothing left for autopsy as it would just vapourize instantly and return to the things in the elements table.
Desire has been ******* this M3 with a turbo I6 a few lapses. It wasn't exactly walking away from us. For some reason Harry's Laptimer (really was the iPhone) must had connected to someone else bluetooth ODB momentarily so no speed info.
I was trying to concatenate two GoPro video files that it created banging my head trying to use GoPro Quik app. I only later realize it is meant to be a quickie for lazy people. It will only generate max length of 60s. So this is the fruit of the exercise. I hate, hate crap videos like this but here you have it.
I invested in two versions of Sony Vegas for Windows many years ago, and that too are some of the worst non-linear editing tools money can buy. PC resource intensive and falls over all the time even with trying to create the shortest clips. GoPro evidently used to have a desktop app that can do this but no more.
I came upon this most unusual race car built with a gen 1 Miata body. The frame is tubular but take advantage of some of the Miata floorpan and body panel sheet metal. The design and workmanship is top notch. It sports an America small block V8 with Edelbrock aluminum cylinder heads. It has Wilwood brakes front and back. There is a thread someone remarked that Wilwood brakes are fashion but I took it in stride.
Wow, that is beautifully done!
Was it the first time on the track for that car? It is way too clean, unlike my car.
Wilwoods are used in all sorts of serious racing. Not sure why someone would see them just as “fashion”?????
I didn't get to see it run. I like how it is constructed, using the underpinning of a gen 1 Miata. It looks more like a hybrid chassis consists of tubular modification to strengthen the Miata unibody floorpan where it makes sense. There are always so much to be learnt at the track just observing all sorts of interesting cars. Some of my best instructors track/race the humblest of cars, while others have the most coveted Rennwaffe.
06-19-2018, 06:21 PM
I agree that the peak is what matter, though a relative long peak. I went to AP racing and can no longer find the three bottle kit they sold. But Racing Shopper has a similar kit. I read that the all-in-one can be hard to read.
GoPro evidently used to have a desktop app that can do this but no more.
