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Ok, time to take it for a spin - but before I forget: When I tested the rears before putting the wheel up, I realized the dustguard was rubbing on the rotor. They need to be bent inward on the upper side, just before the caliper. Easy to do, and 1/4 inch does it. Now nothing is touching or making noise.
Then it was time for a test drive to bed the pads. The first time I wanted to stop the car, I needed a lot of pedal pressure. Hmmm....
The second time, - ah, much better! The third time - holy crap - those brakes bite!!!!!!
Test drive successful - the black coating is almost entirely gone already
when I arrived at the house after the test drive the brakes were quite hot, and there was a bit of smoke and brake smell. They still need to be bedded/broken in some more.
The pedal is nice and firm, but I will still probably flush it a bit tomorrow, just in case any small bubbles have collected near the bleeding points.
SUMMARY:
I am not a mechanic - and this was quite a bit of work, maybe 5 hours all in all. I was most concerned about the brake lines and the bleeding, but should not have been. That part was very simple (using a power bleeder). The rotors are labeled right and left. Unfortunately that did not stop me from putting a rear rotor in the wrong spot first, so I had to redo it...... Someone more experienced than I can probably do it in 3 hours.
In terms of the RacingBrake kit: Great quality and everything worked. I have 2 small suggestions for perfecting the kit for future orders:
1. Rear brake hoses need to be 30 mm longer
2. The front calipers are sitting 2 mm too far inboard compared to the rotor centerline. Not really an issue as the pads have enough play and the pistons simply adjust. However, with thicker pads this might be a problem when new, so, for perfection, the adapter should be modified to move the calipers 2 mm outward. However, that one I will confirm/remeasure after the brakes are completely set. It works just fine as is. EDIT: THIS TURNED OUT TO BE MY ERROR. AFTER BEDDING IN THE BRAKES, IT TURNED OUT THE ROTORS ARE PERFECTLY CENTERED IN THE CALIPERS. SEE FURTHER DOWN IN POST 85.
3. Even though I have the racing pads (XT970 in the front/XT960 in the rear), the is NO squeal at all so far.
Mort, in principle a good idea, but washers would move the calipers further inward. I'll look again tomorrow, but frankly, it works fine as it is.
Maybe there is a certain variation car to car. Let's see whether Blkrokt and MBNRG see the same thing or not.
Just took the car for another spin. The brakes now bite great even when cold and still not a trace of squeal with the 970/960 pad combo. Loving it!
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Wow what a great write up Wobble! Thanks for being the guinea pig on this. For a new product it seems that the RB guys really did their homework to make sure this would be as easy as possible.
I'd like to see the hose issue and caliper spacing issue corrected before my order ships. Hoping to hear from RB on this...
Blkrokt, don't jump the gun on the adapter and caliper centering. It works great and may just be variability car to car. I am confident it will work for you too.
Yes, the rear brake hoses need to be a bit longer.
Regarding the space for weights: my rims are unusual, the are reverse mount custom ADV1s. Behind the flange you see in the photo, there is plenty of space for weights. I will definitely put aluminum tape over my balancing weights to not lose them, though. I had them fall off before, due to heat. ....
Here are the final 2 pieces to the puzzle (I think):
As you can see the rear brake hoses are perfectly fine when the car sits on the ground. There is only tension, when the car is jacked up (or when getting airborne). Almost long enough, but for longevity needs to be made a bit longer.
18 inch winter wheels fit fine in the back. In the front they fit 'almost'. Front rotors need to be changed back to stock for winter, as expected
I re-measured the rotor centricity (whether the rotor is right in the center of the calipers or not). Now, after the brakes a bedded in the right rotor sits within about 0.25 mm of the perfect center of the caliper. The left front rotor within 0.6 mm. I would say, that is pretty darn perfect!!!!
The RacingBrake pads have groves for the stock wear indicator that our cars have on the right side, btw. They can be pushed right in and connected just like with stock brakes.
This is good feedback so far. After the bedded in, seems the only suggestion so far is lengthening the rear brake lines.
Whenever I'm due to upgrade, I'm sure I will go with their rotors and pads since it will be cheaper than OEM.
I am all set to go to NCM Saturday. It will be a scorcher though with 95+ F. A torture test not just for brakes but for cooling incl. oil and transmission in general.
When will the next kits be delivered to the other customers who already placed orders?
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Nice! Tell us about the brakes and cooling!
Also, what laptimer are you using? I'm using Harry's Laptimer on my iPhone but haven't taken the time to figure out how to overlay it on my GoPro video. Yours looks better.
NCM in Bowling Green, Ky is a phenomenal track. It is very complex - more complex than Laguna Seca, Mid Ohio, Lime Rock or Putnam Park, for example. We drove the Grand Full variant with 3.2 miles and 23 turns. There are elevation changes, turns that tighten late in the turn, off-camber turns - you name it, they got it. It took me most of the day to get to know the track. The start/finish straight reaches about 130 mph (braking down to 50 mph at the end) and the back straight (it is anything but straight, rather a fast combo of turns), lets you get up to 125 mph with a blind crest to juice it up.
I went there with 10 10ths Motorsports. Their track days are super professional and work like clockwork. You pay 325 for one day (you can also go 2 or 3 days in a row). If you sign up as Novice, you get a personal instructor free of charge for the entire time. He will ride with you for as long as you wish and give you tips on how to get better. he will also graduate you to be allowed to drive solo and take passengers, if you are competent.
The day was a scorcher - 95F in the shade, more on the track and humid. I have the oil cooling upgrade 44O and boy, was that needed! I would have been in limp mode all the time without, I am convinced of that. Even with the upgrade I saw a lot of times oil in the 240s and once in the 250sEngine coolant never reached 200F. Overall I would say the car is thermally tested and proven robust now.
Last time at Mid-Ohio I also smelled gearbox oil from an overheated diff (at least that is what I think, I also found a bit of expelled diff oil from the vent afterwards). Therefore I also installed a finned heatsink as diff cooling and all was well this time. No smell.
The tranny worked great at the beginning of every run, but later in the run gear changes became more laborious and hesitant. The tranny appeared to be struggling. I could feel it, but it was not a major issue.
Gotta go work on the car now before it is dark. More on video/laptimer and brakes later....
I kept that very simple, and apparently pretty effective: I only had a cellphone with Harry's Laptimer on a windscreen mount (RAM Mount) inside the car. As a result you get g-forces, speeds, lap times (all from the built in GPS) as well as a track map. Works very well and costs maybe 50$ for the mount and 20$ for the App.
I also have an OBD Dongle that I connected to the laptimer to show gear, throttle, and rpm. That worked well during the day, but when creating the video, the OBD signal and the video got out of sync and rpm/gearchanges made no sense. So I did not include the OBD gadget in the final video.
This one is a bit complicated. First the good:
1. The brakes have phenomenal bite, are very doseable and have good brake bias. I feel the rear works a bit more than with the stock setup, but it works great when trail braking and no instability of the car at all. Love that!!
2. The setup is completely thermally healthy. As mentioned above, the day was scorching hot and I drove hard, as you can see in the video above. However, the brake was hard and totally trustworthy all day long. Even when only doing half a cool-down lap it was still fine in the pits. Superb!
3. However, the brake developed a severe vibration problem in the course of the day. Watch the video and see what happens when I brake - not only, but especially at the end of the finishing straight. You will hear and see severe vibration. Not bad enough to really slow me down, but severe enough to not be acceptable.
It turns out, that although I had the XT970 Racing Pads, they were not sufficient for the conditions. Given how I drove (the speeds and braking required, combined with the weight of the car with 2 passengers), overheated the pads and made them smear. The result was uneven pad deposit on the rotors leading to uneven friction and vibration.
Today I had the brakes down again and cleaned them with a steel brush on an angle grinder until the rotors became dull silver again. I hope I removed at least most of the deposit. The pads were glassy and cracked. I sanded the glassiness off and put it all together. Tomorrow I will test it and I hope that the remaining residue will be completely eliminated over the coming days in normal street driving.
RacingBrake is working on getting me a higher level (more uncompromising) racing pad set, the XR70 from a Nissan GTR track car. Hopefully that will be up for the job.
So, in summary: There is still work to do. I believe the rotors are great, robust, there is no brake fading or boiling braking fluid. Brake bias is great. But we still have work to do to define the right pad compounds. What you need will depend entirely on how you drive. Street driving, mild tracking or fast tracking. You may not have my issue, if you do not push the car as I do on the track. I drove about 10 seconds per lap faster than the typical novice in a Mustang. The advanced guys were driving maybe 10 seconds faster, typically in lighter cars.
The Michelin Sport Cup 2s are fantastic. My friend drove an M4 with PSS tires. He washed out at 0.9 g, where I pulled 1,0 - 1.1 g. I even saw blips of 1.2. Wear is also good, except at the outer edge. I do not have enough camber.
The Sport Cup 2s are a huge step up from the PSSes and also the Yokohama Advan Neova A08Rs that I had before.
Note: I have a BS body on the car and am driving 255/35/19 in the front and 305/30/19 in the back. The rear ones are giving great traction and have little wear. the front ones are struggling and show more wear, but are still enabling way faster cornering than the other novice cars.
Love those tires!! They also have a 180 threadwear index. They have different rubber compounds in different places (R-compound on the outside for grip, street compound in the middle and inner side for longevity). It is simply a superior concept - with it's price....
Just heard from RacingBrake. Custom fabricated race brake pads with XR70 sintered metal compound as well as a set of XT910 pads for every day use will be shipped to me next week. RacingBrake is refunding the cost of the pads I fried at NCM.
The new custom rear brake hoses with the optimized length are also ready to go. And I will also test their wheel stud bolt conversion kit, which will make it much easier to swap tires. I am using spacers in the front and always need to fiddle to make the rim, spacer and knuckle line up to mount a tire.
07-04-2015, 02:29 PM
