Yes... lots of pressure results in no significant slowing. Feels sort of like fade, but without the soft pedal.

 

Thanks for the tip! I used some ceramic wheel coating which seems to have helped, the dust so far has been super easy to just spray off. I'm going to re-coat the wheels this winter to stay vigilant, so thanks for the heads-up!

I installed my brakes, gave them a couple of hard stops from ~100+ mph on the street, then drove straight to the track the next day. My first session with them at the track was maybe 8/10ths with early braking, and they never really felt like they had much bite. I know I put some heat in them there, and was afraid I might have glazed them or something, because I could smell them after that (and see some heat discoloration in the rotors).

I let them cool after that first session, and did pretty much the same thing the 2nd session. Finally on the 3rd session that first day I drove them mostly like normal, but they still didn't have the bite I expected (and still don't, to be honest). At the time I was afraid I fucked up bedding them in, but that's what the instructions said (basically don't brake them in on the street, or even try, and to do some hotlaps braking early). At this point there's very minimal wear on the pads or rotor, so I've been accrediting it to them still breaking in, they have seem to gotten better each session since I got them on and I'm finally getting some trust in them.

Agreed, very wooden. Not a soft pedal, which usually would make me think I need a bleed. This is a super firm pedal, almost standing on the brakes, and not a whole lot of stopping. They get drastically better if I drive like a doofus on my warmup lap and force heat into them, then I can start to trust them. Otherwise they feel.. wooden.

Interesting. What was your "break in" procedure? I always assumed that if I went out for a full session, 20+m of hotlaps, that by the end of it they'd be fully broken in and feel better. I just haven't done a HPDE or trackday where I get that much track time in one session. Typically we get between 3-5 "sessions" in time attack format (like my videos show), so honestly I've been just telling myself those pads must be way overkill for what I'm doing (I was able to get away with sport brakes on hawks for a few seasons afterall).

Agreed, this is exactly what I'm talking about. I'll start with a fresh bleed, but I'm convinced they aren't broken in, or need more heat to make a transfer layer, or something.

 

I've experienced similar with DTC60s, and at my recent track days at PIR and Sonoma, my stoptech sports felt great, without much, if any, change in bite, however I wouldn't recommend the Stoptechs for much more than 20 minute sessions. Great pad to run around on daily and still work if you get a desire to slap an "instructor" sticker on your car and do a couple sessions.

Shameless plug for my boss who owns the place, but if you guys want a pad that stops the same cold, wet, hot, or on fire, try Cobalt Racing, they last a long time, zero special bedding required, and last down to the backing plate. Bonus, looks like they're cheaper than the R12s by about ~$30. The "optimized" pads have a small amount of extra pad material, but won't fit OE hardware and clips. Lots of aftermarket fitments including Wilwood, Stoptech, etc. If you have any questions about them, I'd be happy to get an answer for you. https://cobaltbrakes.com/shop/oe/mazda

 

Huh.. my "break in" procedure was very similar to yours. I followed the G-Loc instructions to the best of my ability, and I think I tried to take 949Racing's instructions into account as well. Gave my rotors a cut on the lathe to get rid of the old transfer layer, went out at night and did a few stops from 100mph down to 20mph with as much braking force as I could. After 4-5 stops, the pads started emitting a burning smell. If I remember correctly, the directions I had stated to "pull off track, use as little brake as possible, and let the brakes cool for an hour" once they start emitting that smell. I followed that as closely as possible, but my "test road" is 7-8 minutes from where I live and I live halfway down a hill, so I had to use the brakes some to get home.

Maybe also of note, I was swapping back and forth between G-Loc GS1 and R12/R10 pads for street and track. I'm pretty sure doing so had no adverse-effects on the transfer layer adhering to the rotor, since the GS1s are still a carbon-kevlar compound.

From G-Loc instructions:On your out lap (1st lap time on track) on the track perform a few near stops. This will get the two surfaces (disc and pad) to mate up and put down a transfer layer into the micro-grooves on the discs. Then, drive like normal (but back up your regular braking marker/point) for about 3-5 laps. During your 3-5 laps at some point you should feel the pads fade all of a sudden; at that point back off the throttle and cruise back to your paddock spot and stay off the brakes (as much as possible) and let the car sit for NO Less than an hour. DO NOT run more than 5 laps at speed while performing the bedding process (even if you don’t feel them fade). Allow brake pads and discs to cool down to ambient temperatures.

NOTE: Do NOT try and bed your track pads on the street. The only way to properly bed them is on a race track (closed circuit).

949Racing Instructions: https://www.949racing.com/supermiata...4OY_FoEhvRtXZ6

My R12s also bit crazy f*cking hard before I performed the bed-in process. I could sneeze and lock up all four tires, not even exaggerating. After getting to the "feel the pads fade all of a sudden" part, they never bit that violently again, but were still pretty grabby until getting some heat in them.

The fact that you two had similar experiences opposite to mine make me think that I'm probably the one who did something wrong lol.

Edit: Just saw Curly's post. Took too long writing mine before hitting the post button to see it hah. I'll check em out. Haven't seen much buzz about Cobalt before but always game to consider a new option.

 

Biggest complaint I've heard of Cobalts is squealing when cold, dusting, and chunking a bit when worn down past the rivets*. In my experience, that's all standard race pad behavior.

*These are actually screws clamping the pad compound to the plate (with glue** too), each head is individually counter sunk by hand for the final product.

**really fancy glue

 

Looks like fun man! Ya I find it definitely helps having fast people ride along with me to point out little things I'm doing (or not doing) to improve. SM guys are usually the fastest drivers (so I've been told) because they're the only class 30+ cars deep and very competitive. My buddy Dave who's my "Stig" has been kicking butt in SM since switching from SSM but doesn't have the desire (and pocket book) anymore to try and compete nationally and do whole seasons anymore. I'll be curious to see what times he can turn next year when I get a proper diff in the car.

Regarding pads.. just my 2 cents.. I'm not a big fan of G-loc's. I believe they are a sister company/similar pad compound to Carbotech (something like the old owners or something left Carbotech and formed G-loc?). I honestly have never used them but I had several friends who had finicky issues that you guys are describing with carbotechs and bedding them in. I know their instructions are to only use a similar pad compound on the same rotor and to not switch compounds. I started with Hawk HP+ on the honda, and they worked for my first couple track days and had bad fade one time so I stopped using them. Basically just didn't have the bite w/ the same pedal pressure (the compound got overheated). Then I switched to DTC 60's and 30's. Honestly I thought the Hawks were good. Good bite, no fade, ok modulation, zero bedding issues. I stopped using them because apparently the brake dust is corrosive to paint..? Supposedly they're "hard" on rotors also but honestly I think the difference is probably minimal. I switched to PFC (performance friction) and have been running them since. They seem very similar to Hawks, maybe slightly better modulation, good bite, and no bedding issues. Only problem with the PFC is they scream/squeal like a ****. I run I believe PFC 11's up front and 97s in the rear. Downside is they do cost a little more than hawks. I like being able to swap pads without having to worry too much about bedding. I think I run the stoptech street pads on the front calipers on the street. Just my 2 cents.

 

I never had squeal out of PFCs but it was terrible with Hawk products.

Modulation was always perfect on PFCs. I ran Cobalt also. PFCs are my first choice.

 

Ya I'd swear my PFCs didn't squeal badly on my Honda but they straight SCREAM on track w/ the miata. Not sure what's different w/ the miata but they are LOUD. I'd think it was maybe a rock but I've swapped them for different events and both events they scream..?

 

The Hawk's I had on my sport brakes (I think HP+) were TERRIBLE in the noise dept. I can handle a pad that gets loud on the track, but not one that is downright embarrassing to drive on the street.

I really appreciate the pad discussion going on here. I'm currently hoping I can get these G-Loc's to work better for me, but if I can't get any improvement out of them I'll definitely be switching. I'm going to bleed the brakes again, and hopefully do a HPDE session in the spring. I really think they need a good 20+ minute session and they will fully break-in and work for me. Time attack is a weird format, and these brakes are so thicc I just think it's a heat thing.

 

Try hitting the rotors with brake cleaner and re-bed them.

Some say that the back side of the pad rubbing the caliper is the source of brake squeal. If so, it may simply be how snug the pad is in the caliper making the difference.

 

No real updates, took the car for a rip this weekend and all is well. Snows falling in the mountains here, so probably the last mountain run I'll do until the spring. Cars RIPPING in the cold weather, and we had a great time enjoying it. It looks really out of place and kinda crazy out on public roads. I like it.

 

Dang, looks like you guys are about ready for opening day! They're still just blowing manmade snow down here.

Car's looking good! I agree with you regarding track cars on public roads. Love the look of a dual duty track car on the road more so than something with a traditional aftermarket body kit.

I need to get or rig up something like those rear spats/flares you just put on. They're subtle but look awesome.

 

I told myself I would leave this car as-is and focus on the FD, but I decided to tear the car down a bit for some reliability upgrades.

First, I've been sitting on a Supermiata crossflow rad I got for black friday in 2023 and haven't installed. While tearing the car apart I had forgotten how annoying those damn racing beat sway bare re-enforcement blocks are to R&R, and the AWR bolt-in mounts were cheaper than I thought - so I pulled the trigger on those. They were actually super easy to install and I'm thrilled with them.

At the same time I ordered the FM silicone hose piping. This will remove 5 couplers and 10 t bolt clamps from the system, so I'm thrilled on it from a reliability standpoint. I haven't had issues lately, but I have blown a coupler at the track and it SUCKS (ask @redursidae ). Also they should have notable flow benefits compared to my hacked together setup. We'll see how it fits with my kraken kit and not-FM intercooler setup

Speaking of intercoolers I have a fab9 stage2 I/C i bought in 2023 as well. After buying it and see it in person, it's larger than I expected, and I kinda started second guessing that decision. At the time my thoughts were to go overkill on cooling and the big I/C was part of the thought process of getting this car setup to run high boost (15+psi) at the track instead of the ~12 I usually run and keep IATs low. However, after reading every single thread on ducting, oil cooling, and general cooling theory I'm concerned it's too big. You see, my current IC setup allows air to go over and around it easily to get to the radiator, but this stage2 intercooler will pretty much take all the space from the undertray to the bumper beam without much bypass directly to the radiator. I think with good ducting I can make it work though, so I'm going to mock it up and see what it actually looks like, and how each of my I/C's work with the FM pipng, and go from there. Stay tuned for that, and input welcome here. I'd rather not trim or delete the bumper beam, but I've considered that as part of this setup as well.

And speaking of cooling stacks, I'm going to finally get an oil cooler on the car in preparation for longer HPDE sessions. I've mostly decided on the "big as possible behind the radiator" approach, and replace the pass side fan with the oil cooler. I like the simple oil line routing there, and the protection of the oil cooler with this setup, and figure with hood vents and good ducting it should get plenty of cooling, and certainly better than nothing.

Finally, I've been wanting to build an actual splitter for this car. Though I'd like it to be quick release to get it on a trailer. The problem is that none of the kits I found will work with an intercooler (namely the piping), or at least my intercooler setup. Maybe the FM piping will help in this regard, but I don't really see anything off the shelf I can buy splitter mount wise - so I think I'll have to fab something. This is last on my list, but something I've had in the back of my mind for a while. Any suggestions about this here are welcome. I can tell you the 9LR setup absolutely has no hope of fitting with my IC setup, gutentight looks closer but would probably need some things re-worked. I considered getting some of the universal ones from ebay and just building bracketry of my own, but I'd rather find something that bolts on if possible.

 

Hell yeah, love to see it dude! You’re so deep in the RX7 project that the little change of pace here will probably make going back to that project fresh again later.

Are you tracking oil temps as-is already? Curious what they’re getting up to. Even during your guys’ 3-lap sessions, I’d imagine they’re getting decently warm.

Also can’t wait to see what you come up with for the splitter, and what balances out well with the 9LR street ****.

 

Love it.

1. Did you document your valve cover mods in this thread?
2. I like your catch can location!
3. Do you have any shielding on the sides of your radiator to cover the gap on both sides?

 

Maybe trim the plastic bumper support and top of the bumper mouth like I did to allow large amounts of air to travel over the crossbeam to the radiator? I also designed my undertray to leave some space between it and the bottom of the intercooler for airflow to the radiator.

 

Thanks!

1/2) I did document the valve cover mods + catch can, sometime in 2021/22 I think. This was required for my car to turn hot laps without filling up the catch can once I started getting faster at the track on sticky/modern super 200's. The key points were capping off the cold side (pass side) instead of routing it to the can (I think this was pushing most of the oil since my local track is mostly left hand turns), boring out the internal baffling and adding the 2nd vent off the hotside (high volume of PCV venting = low velocity = less oil pushed into the can). Now I go entire track days without looking at the can, and even when I empty it it's maybe a few TBSP collected. Before I'd overflow the entire can in ~2-3 laps. Location choice was just ease/simplicity of line routing, so function > form but I dig where it's mounted as well!

3) The radiator was fully ducted, though in these latest pics all of that is ripped out. But I absolutely ducted the sides/bottom, and had the top sealed off with the aluminum panel/tape to the rad. Ducting was key for this car, and I did not have overheating issues last year with the hood vents. The additional cooling is pro-active so I can run more power and push the car harder for longer.

This is a good idea. I was thinking of trimming the stock bumper support so I can get more airflow but keep the rigidity of the stock bumper beam. I'm not super worried about impact rigidity, but I don't wanna make the chassis any more flexy and cutting that bumper beam out (even with a bolt-in replacement) seems like a bad move to me. I could be wrong.

I'll mock up that stage2 intercooler soon and get a better idea of what that actually looks like, and post here for some input.

 

I recall someone (probably Emilio) posting a picture of a bolt in aluminum brace that went in front of the engine, looking to stiffen up the structure. It was flat plate oriented vertically, with two welded on bolt locations on each frame rail so as to resist any twisting of the chassis.

By and large though, I've not seen anyone say they felt a noticeable loss of rigidity from cutting away the beam behind the plastic bumper. Proper cooling that you never are concerned about on track is definitely more important than a small bit of chassis rigidity IMO.

 

Yeah we always remove the bumper support beam for better cooling. IIRC that's even in the Miata Cooling System Thread/cooling system FAQ.

You can also tilt the intercooler if there's room, though that will of course significantly hurt flow *through* the IC.

Another option is to remove the bumper beam and build a lil duct in there that scoops down partially in front of the IC to direct air up and over it to the rad.

 

After reviewing some trackday logs and thinking about it for a while, I decided to go ahead and run the stage2 vibrant core I have already. It might be overkill but IAT's were hitting 145*+ on higher boost and climbing. The old ebay IC did well, but it's time to go.

This new unit is a HUNK. I'll have to weight it, but it's gotta be 10+lbs compared to the super light, maybe 5lbs ebay core. Good thing I'm ditching the steel IC pipes for the FM silicone pipes, making the weight gains minimal overall.





After reading about intercoolers for a while I can really appreciate the new core vs the old ebay one. Old ebay core:



New vibrant core:



The fin density and staggered fins should be way more efficient on this new unit, plus it's huge, so I expect to be able to hold 15-20* over ambient with this. I mounted it differently than suggested, following the tips of a few folks I've seen install these, and welded a nut into the non-threaded hole. My first welds on this car, which was pretty cool. Not perfect, but I'm a good grinder.




This puts the intercooler in a better position. A few inches further in, which gives air a path over the IC to the radiator. It also keeps it from being mounted so flush to the opening, giving it a better mouth before hitting the IC. Not sure if this is enough, but already a step in the right direction. I do think with some trimming I could get this looking a lot better airflow-wise. I've really got to decide if I want to trim up the stock bumper beam and try that, or just go for the delete.







Also mocked up the supermiata crossflow, which is a damn SEXY unit. It's so light and fits great.