Ideal brake setup w/ 1.6 & 1.8 calipers/brackets?
 

I'm still running the 1.6L brakes on my 93 track car. Stoptech street performance pads front, wearever junk pads in the back. Budget does not allow for 1000 brake kit, and 300 in pads. There's enough pad to lock the front tires (somewhat sticky bfg Rivals), and brakes don't fade on my home track (Nelson Ledges - pretty easy on brakes). So I don't see much reason to go to bigger rotors or calipers, unless I'm missing something? Longer pad life? Yes, bigger = more brake torque, but I can already lock the tires (no ABS), so that is limiting factor. R compounds in the future, possibly, so that may change. Bigger rotor will soak up more heat, but not having heat problems yet.

1. I've read all the hoo-ha about how much better 1.8L brakes are etc etc, and all the stuff about the 1.6L parts being lighter and thus less unsprung weight. Which is faster on a turbo miata?

2. Brake balance is currently front biased, due to more aggressive front pads and stock proportioning valve. I'm due for pads and will be, most likely, going to the Stoptech pads all around. Would going to 1.8 brakes rear only balance things out better?

3. If I'm able to lock the tires and aren't experiencing fade, is there any other advantage to running Hawk or Carbotech compounds?

Anything else I'm missing? I thought I'd be overpowering the brakes at this point, maybe I'm not using them hard enough... No hose ducting yet either, but will be added this winter.

yeah, having a setup where all four wheels help stop is always nice.

Indeed Scott, indeed...

I had actually left the rear with the junk pads on purpose after reading somewhere else that there would be too much rear bias without an aftermarket adjustable rear valve! Must have been the other forum...

Edit - I just saw that mashed potatoes bit... Dare to be stupid!

One thing I did to my 90 Miata track car that gave really good results was installing a 2002 Miata LS sport package braking system front and rear. Hawk blue compound and stainless lines.

I don't have any exaggerations to go with this, it just allowed me to threshold brake through an entire race at VIR with no brake fade.

Thanks Jeff, I've been looking into doing something similar - I assume you mean the larger master cylinder & booster as well? There's a long thread on m.net that I had gone thru.

Did you track the same pads previously on the 90's original 1.6 brakes and experience fade? I'm looking for an apples to apples comparison, hard to get because everyone seems to go upgrade pad compounds when upgrading the 1.8 brakes, so you don't know how much the larger rotors helped.

Also it's my understanding that you can just go to 1.8 rotors and brackets and reuse your 1.6 calipers with 1,8 pads, and get larger area pads as well. I could see that being an advantage to pad life.

for the brakes I used the 02 sport calipers, brackets , pads front and rear. I maintained my OE 1990 master cylinder and brake booster.

Yes when I had my original 1990 brakes with slotted rotors and Hawk blue pads, approximately 15 minutes into any track session or race I would lose threshold braking. I'd find myself hitting the pedal a full 100yds sooner just so I wouldn't run off track. When running down the top 3 guys that loss of braking hurts

Thank you Jeff, that is good apples to apples info. I'm typically running 20-30 minute sessions, so it sounds like going to the larger oem brakes would be worthwhile.

It's possible to make the stock brakes work, but it's not fun. Rover in full PTE trim ran the tiny stock 1.6 rotors and calipers front/rear as required by rules. No limits on the rest of the parts, so I ran NB Sport 15/16" master, NB non-ABS booster, Trackspeed Wilwood prop valve kit, Hawk DTC-60 pads front/rear. The pedal felt like shit, but it was consistently shitty and never really affected the stopping distance of the car. It was fine at most tracks, but it did require that I run high-dollar fluid (Castrol SRF) at Laguna Seca to maintain pedal feel through 30+ minute races.

I've since switched to 1.8 brakes and the pedal feel is better, but not fantastic. The Sport fronts in Thumper are significantly better. Next time Rover needs brakes, I may throw our 11.75" Wilwoods back under it. Nothing touches the pedal feel of the 11.75s.

Thanks Savington, didn't realize the sport brakes were such a big improvement. No doubt the Wilwoods are even better, although that's a massive rotor for a 2k lb car. Do the pads last longer on track vs the 1.6 setup, given the larger pad area & larger rotor swept radius? (I also need to do a bit more reading and verify the sports will clear an OEM NB 5 spoke wheel.)

I guess what I meant earlier with post #1 was that Yes - you can put on a big brake kit, go to Corrado rotors or similar, etc, etc... But isn't there a point of diminishing returns, bigger rotors/calipers being heavier and heavier?

If the car stops and you can lock the wheels if you press hard enough, the brakes don't fade after 30 mins of hard running, and the proportioning f/r is well sorted... what's to be gained by going to larger brakes?
Just a pedal that feels better?

It's worth it to try and evaluate the difference for yourself. As a driver my style differs from your, just as yours does from Mr. Savingtons.

My style with 02 sport brake feels perfect, and with 1.6 felt shatty.

The Wilwood BBKs typically drop unsprung and rotating weight because:
1. Aluminum hats with separate rotor vs. 1-piece cast rotor.
2. Aluminum fixed caliper vs. iron floating caliper

Besides weight, main advantage is lower maintance. The OEM calipers will taper your pads like crazy. You can get a lot more track days between brake jobs with the BBKs.

Jeff, agreed different strokes for different folks. I'm not in your or Savington's league though, you guys have more experience to know what works and what doesn't. And what is fastest, given the available parts. Thank you both for the first hand recommendations.

Hornetball, yeah I get that much, but this is just trackday fun on a budget. Unsprung weight and rotating mass were my reasons for not upgrading to 1.8L brake parts.

Brake pad taper is actually something I keep meaning to measure - never noticed any obvious tapering, but that was just by eye. What sort of thickness differential is expected, and how much is too much?

After another few hours of reading, it sounds like NA folks are running the standard 1.8 bits up front and running the sport 1.8 bits in the rear to get a better bias, with either the NA or NB master/booster...

As with everything else, this is another rabbit hole to fall deeper and deeper down into...

No need to measure it. When you start hitting the brakes often and hard it'll happen and be obvious to the naked eye. It's just a property of floating calipers.

It's not too much of a problem by itself. It's just that the uneven wear shortens pad life. Just keep an eye on them and replace the pads when the wear slot goes away. That's all I do on the Silver car. Frequent brake jobs and I've found a less expensive pad that works for me on that car.

The Red car has the 11" BBK up front and the extra life you get is noticeable and welcome. Pads wear even and you can let them go much longer. But the pads are more expensive, so . . . .

You're right, quit obsessing about it and go hit the track. You'll soon find what you need to upgrade. LOL.

Yeah, that's what I've been doing. I've been waiting to replace the pads til I figure out what I'm doing with the rest of the brakes, so I'll be curious to see how bad they are tapered...
Out of curiosity, what pads do you run on the silver car?

So, here are the options for my 93 using off the shelf miata parts:

1. Upgrade to standard 1.8 rotors/brackets/pads in rear only, thereby improving overall brake balance, and going to adjustable proportioning valve

2. Upgrade to standard 1.8 brakes front and rear, thereby improving heat absorption/shedding, more pad area (and possibly longer life), and higher possible brake torque. Adjustable proportioning valve also, but will probably be full open.

3. Upgrade to standard 1.8 brakes in the front, upgrade to sport 1.8 brakes in the rear, thereby improving overall brake balance, more pad area (and possibly longer life), and higher possible brake torque, and going to adjustable proportioning valve

4. Upgrade to sport 1.8 brakes front and rear, thereby improving heat absorbtion/shedding, more pad area (and possibly longer life), and higher possible brake torque. Adjustable proportioning valve also, but will probably be full open.

Other options:
Could also go to the larger/later NB master cylinder (15/16) for a harder pedal w/ less stroke to actuate, or even the 1" 929 master.
Could also mix and match brake boosters for more line pressure, though it looks like the NA master and booster don't mix with the NB master and booster.
master/booster thread reference:
Some interesting brake information (tech!) - MX-5 Miata Forum


I'm leaning towards option# 3 or 4, and considering going to the NB master and higher ratio single diaphragm booster
Edit: This is assuming running same type pad front/rear, bias taken care of by brake hardware/adj. proportioning valve.

I think you've been reading too much auto-x braking threads. Track guys dont seem to want nearly as much rear bias as auto-x people.

Just fixing a little error from post #5, with the 1.8 brackets and rotors with 1.6 calipers, you still use 1.8 pads, NOT 1.6.

Again, the larger 1.8 pads fit in the 1.6 calipers.

Leafy - yeah, possibly...

Curly - thanks, fixed!

:)

you seem to have your mind in a jumble when it comes to figuring out what system you need/works best. Without diving in to too-much boring information i will say this. the only way you can change TQ on a braking system is

1 Rotor diameter
2 pad compound
3 hydraulic advantage.

Remember the Goal isn't to get the maximum amount of TQ. The goal is to have a balanced system (front to rear) without overloading the tires. If you're racing on 195mm falkens your requirements are going to be drastically different than someone running 225 slicks.

It probably does look jumbled, collectively. But its not confusing, everything is pretty straightforward.
There's also
4. booster ratio, which multiplies your hydraulic advantage
5. tire compound & width, as you alluded to

That's why I'm asking, plenty of folks are running on the same rubber (205 rivals) as me with similar suspension and power. Which combination of parts from post# 14 yields the fastest (and best balanced) car?

Right. just so we are on the same page. the tire Doesn't change the Tq output of the braking system. Changing the MC will affect tq. But because you have a single MC system, changing the MC won't change Tq Balance. FYI a larger MC actually decreases Hydraulic advantage and Tq. a smaller MC increase Tq but it also increases the stroke. In every pedal there is a point of no return, when it comes to mechanical leverage. it's generally at 6 o'clock (straight up and down). If you go too small on a MC your travel will increase, going past that point you're losing mechanical advantage and your pedal will start to become harder.

I was a factory rep For a major Performance Braking systems manufacturer. I know more about brakes then anyone should know.. Dont ask me anything about turbos, i don't have a clue. :P


enough with the boring brake engineering.
Miata's brakes from the factory are very front bias. The majority of this comes from the factory proportioning valve. as you hit the brakes harder it cuts more of the rear flud off. Hypothetical situation as to why mazda does this - if your mom hits the brakes on a wet road, in the middle of town, she doesn't go looping off into some tree. it will simply lock up the front tires and your mom is saved.

if you're in a class that allows it, remove that prop valve and replace it with the flyin miata valve. that's the one i got, i love it. this will remove the choking off of the rear brakes. after that you can run a square braking set up. same compound pad F&R.


If your want to keep your car spec miata legal, then we'll throw a higher tq race pad in the rear to counterbalance the factory prop valve.

- Correct

Tire compound & width will affect how much torque the brakes can generate without locking up and skidding.

My intent was to mix and match components for the best budget brake system - best braking, no fade, able to run less than "race" level pads (ie, the Stoptechs), balanced front to rear (or at least better than it is now), and be wallet friendly. Such a thing as best is going to be subjective anyhow, but thru trial and error I'm sure there are "best/better/good" options. I figured somebody here has done that, whether they're trying to fit into a class, or just a cheapskate like me!

- No worries, you're talking to an engineer :)

Agreed on the front bias, that's what I'm trying to correct with some of the options I listed, adding rear calipers/rotors that are further upsized than the fronts. I'm not worried about fitting into any class, I just do trackdays and hpdes. I probably will remove the factory proportioning valve and go adjustable, though it's another thing to fiddle with on a car that's already pretty fiddly... Ideally the brakes would be balanced without having to really choke off flow to the rears, basically running the adj. prop valve wide open.

Finding a Street pad that will take race temps is going to be hard. the Majority of street pads out there contain fillers that are combustible. see attached img. The stoptechs i assume are like the PFC 10 compounds. able to take elevated heat over a autozone pad, but these are still a street pad. you will find the limit on a track day doing multiple 20 min stints.
https://www.miataturbo.net/attachmen...ine=1406649637
it's cool to try and go cheap on a race car. the sport is damn expensive. but cheaping out on pads is always going to bite. You might save $20 running a Stoptech or PFC .10 over a set of race pads. When your street pads let go it could ruin a weekend that you have over $900 invested.(think track fees + hotel= food ect..)

the cheapest way of going is running the prop valve & 1.8l brakes F&R.
not mazdaspeed brakes, finding race pads for mazda speed brakes is a pain.

That's a great picture!

I had seen a spec somewhere for the stoptech performance pads, I belive peak temp was 1300 F, that's well into race pad territory. I don't know what the friction curve looks like approaching that value ( I suspect it's aleady dropping off rapidly, and pad life is probably awful at such a temp), but I've had them smoldering hot without any fire. I can actually get them hotter on the street with back to back accel/brake runs 70-10 mph (as in rebedding them) than I can on my local track. Obviously that might be different at a more brake intensive track.

Mazdaspeed brakes are NB sport brakes I thought?

Yep they are.
One thing to consider when being cheap you might not be saving any money. My point is replacement costs. I have the trackspeed 11.75 BBK. I have about 100 more hp than most people on this sight (LS1 car). I Ditched the Wilwood rotors that it came with and went with PFC 01 pads and PFC 8x7 rotors. I track my car 2-3 times a month (field rep and my car come with) and i'm on year 3 with the same rotors. I know that allot of spec miata guys go thru pads and rotors allot more often than i do, and they are 350hp less then me.

QFT.

If I ever buy a miata again, first thing I'm doing is upgrading the rear brakes and adding a prop valve.

Looks like my pads are available for both the 1.8 and 1.8 sport/msm brakes. I'm curious which pads aren't available for the sport/msm?

I should also 'splain that I already have 1994 1.8 brakes laying around on my parts car. Sport brakes would come out of my pocket.
So the question still stands, which are the best parts to upgrade to? :)

the larger the rotor the more tq, also larger rotor will last longer. install that 1.8l kit and add a prop valve.

Finally got around to actually checking the calipers and pads (was in the middle of a trans/clutch R&R)...
Hornet called it, my pads were indeed frighteningly tapered after 2 track days with boost. This then is no doubt the fantom crappy brake syndrome I've been chasing, probably just wasn't this noticeable before and I wasn't looking for it. Thanks!

On that note, I'm looking at the front brake setup with the Willwoods and Mini rotors that it appears Relte and EO2k pioneered.
MINI 11" rotor instead of Corrado - Miata Turbo Forum - Turbo Kitten is watching you test compression.

Then going to 1.8 sport in the rear, and adding an adj. proportioning valve.

Thank you gentlemen.