Input needed from those with 2pc rotors
 

I'm currently looking at making some brake system improvements over the winter to prepare for next year's track events. Current setup is as follows: z1 1pc slotted rotors F/R, carbotech pads (1521 for street, xp10/xp8 for track), z1 braided lines, Brembo htc64 brake fluid, stillen brake cooling kit.

In 2 days at Laguna, I've taken my xp10's down to approx 5mm and developed quite a brake vibration in my last session of the 2nd day, rotors (especially fronts) appear to have dealt with TONS of heat, although I don't have much info on rotor temps other than measuring 733* when checking immediately after a session at laguna on one of the fronts. First day at laguna was 9/3 and 2nd was 11/1, and I was significantly faster the 2nd day (thanks to Racers360 coaching and lots of work in the simulator). Purely speculating here, but I'm thinking I may have exceeded the cooling capability of my current setup, although I am not 100% certain. I track with HOD and was fairly comfortably the quickest of the B group (intermediate), with times that seemed fairly comparable to some guys in the advanced groups (purely guessing based on the gap between me and a C7 z06 and everyone else in the B group last time out)

Currently looking at making some inlets for my front bumper and modifying the stillen backing plates (or making my own) to accept 2.5" or potentially even 3" ducting, and going to 2pc rotors. I've been looking at the DBA 5000 T3, Racing Brake 2pc, and Z1 2pc for the front and was looking for any and all input on these rotors and pad selections for both street/track. In doing some reading I've seen issues with RB rotors and some pads when it comes to pad deposits (I believe they recommend Hawks primarily) but wanted input from those with our cars to see what works and what doesn't. I'm determined to keep getting quicker and quicker in the car and am hoping to find a setup that will handle everything I can throw at it now, and also provide some room for growth as I get even quicker.

Thanks in advance for all input.

Sorry I won't be able to provide additional input - but I'm seeing more and more track guys coming up with vibration/issues that are running the XP10/8 and Z1 rotor combo. I have that issue myself, and get this really weird vibration that happened only after I ran Autoclub with that combo. I've also burnt the paint off the rotor rings on the front rotors...

From what you've seen is the vibration exclusive to their 1pc rotors, or does it also seem to be the case with their 2pc rotors as well?

Go with the Racing Brake 2 piece. If you can't stomach the price, next best option is DBA 2 pc.

The Z1 2 pc are almost too lightweight for the track. The unsprung weight is nice but the mass of a heavier rotor like the RB 2 pc dissipates heat soooooo much better, which you really need if you are pushing the brakes.

Which pads do you run with the RB rotors, both for street and track? I'm leaning heavily towards them, but I love the feel of the xp10/xp8 and would like to continue using them, or at least get something similar in feel and performance.

You need the heavier rotors for track days. I love my Z1 2 piece rotors. I have had zero issue in over 100k miles. The heavier mass rotors will help with track days and heat dissipation.

It just depends. I have heard a bunch or really good track rats go to oem or other compatible blanks and do well. I don't have any experience with z1 one piece up front but have a set of their 2 piece rotors that I have been tracked for a couple of years. They have performed as advertised. I did have some shutter the last time I ran with them a Chuckwalla Valley. It was with a new set of pads same as what you were running. I think that my experience was due to it being cold temps in the 40s and 50s and 3" brake ducts. Over cooling is not good with aggressive brake pads.

I would take your time and do the brake ducting first. I would also check out Stoptech rotors. I did their 1 piece on my wife's Audi s5 along with their street pads and they are as good as what I run on the Z. Their 2 piece rotor are a floating rotor and are slightly cheaper that Racing Brakes. They are also heavier than z1 but lighter than oem.

Over cooling is something I didn't even think of, but now that you mention it... When I was at Laguna in September and had no issues with any shutter, it was definitely warmer than it was November 1st. I don't know the exact temperature difference, but it was definitely colder. This has me thinking about finding a way to have adjustable vents to be able to tailor ducting to the cooling requirements of a particular track, like they do in F1. Would definitely take some learning but I'm very intrigued by the idea.

If I had not have blown my motor LOL, I was going to cover the inlet with painters tape.

make sure there you check for the pad/rotor combo before you use it. some combos react poorly

IIRC someone found that DBA 2 pc rotors did not work with Endless pads due to the materials used in each

Ask Rusty.

I've got a set of Z1 2 pc rotors on the car now with XP8/10 pads. There's a good possibility I will swap them out for RB rotors before I get the car on the track. I like to brake aggressively.

Sounds like the OP is also aggressive in his braking. I tend not to wear pad and brakes as some due to my braking style or lack there of, but yeah you have to know your driving style and purchase equipment that matches and suites your ability and style.

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I started using the Z1 2 piece rotors this year along with XP10/8 pads. I also have brake ducts with 3" tubing. This combo worked great for me at Pitt Race in June and the Glen in July. Then in October at the Lightning I had a lot of shudder and vibration. I'm planning on switching over to RBs over the winter.

If your pads get wear down less than half you may get some shudder. I have and new brake pads fixed it. It's a thing with Akebono brakes for some reason.

I think the same, I use the pads for full season or more, where some brz/86 friends with AP racing wearing their pads before the end of the season, there is other that don't wear their pads at all. I have Z1 2-piece rotors with endless mx72plus now and they work great.

It all depends on the habit of braking.