Big Brake fun
 

We're exploring some different brake options for production kits we will offer as well as one-off kits for our S1 Supermiata build, "Vegas". This thread may ramble a bit but I wanted to show what we're doing as we go along.
We just received a pre-production Stoptech ST42 based BBK for the 89-05 Miata. Centric own Stoptech so they can offer a start to finish upgrade kit allowing and NA6, NA8 or NB1 owner to switch to NA8/NB1 rear brakes or NB2 Sport rear brakes with appropriately sized master cylinders and ST42 piston sizes. It's an ala carte system. A bit confusing thus far with all the options. I'll work on a table that makes them a bit easier to understand and post soon. Meanwhile, lets look at the calipers.

The big Superlite 5.98" radial mount on the left is what I'm trying to fit onto Vegas. 15x10 6UL's with common 11.75x .810 rotors so we're hoping they'll clear. If we can make them fit, we also want to experiment with fat 11.75 x 1.0" rings.
Our two objectives with the Superlite are greatly increased pad volume and the potential to fit a 1" wide rotor.
The ST42 based Stoptech kit will go onto Taxi, our 180whp N/A HPDE build with the Quaife Sequential.
Love bridgebolts!

https://cimg4.ibsrv.net/gimg/www.mia...ce87d011a6.jpg
https://cimg5.ibsrv.net/gimg/www.mia...95bc2c5110.jpg

Overall, the ST42 looks to be a higher quality caliper than the Wilwood but that's just subjective external observation. I did notice the pad thrust plates are really beefy, one piece and bolted in. The same item on the much larger Superlite is a thin gauge, spring that clips onto the caliper much like the teeny little plate on the Dynalite. We have had issue with plate wear and retention on the Dynalite in racing environments before so they get timed out and replaced. Several small details on the ST42 impressed in the same manner.
https://cimg6.ibsrv.net/gimg/www.mia...aaff2c6778.jpg

Do you have a 4 piston Dynapro caliper to show as well?

Did not have one handy. It's a tad larger than the Dynalite, smaller than the ST42.

Huh, even if the Afcos are private label manufactured by Stoptech, they're definitely different in a lot of details.

I guess you called Andrew at TSE for some help ? He must know many things on this subject.

My TSE 11.75'' V1 and 6UL 15X9 +36 + 10 mm spacer and I can't have those glue weight inside the wheel as they're no eough room. Anyway, reace car only so it doesn't matter.

joyrider, the caliper isn't necessarily any larger from the hub center than the dynalite is.

dynalite from willwood spec is 6.76inch radius on 11.75 rotor and superlite is 6.81" radius on the same rotor.

that's 0.05inches different. pretty sure the wheel barrel wont be a problem with 1mm of growth.. or since its radial mount, you could probably space it towards the hub a hair tighter than spec but you would need to watch for rotor growth.


How tight are the rotors to the balljoints now? you should be able to spec a slightly higher offset on the brake hat to get a bit more spoke clearance, but I haven't seen how little space you have to work with on 11.75 rotors to other things like the balljoints

The DR22 pad is the same dimensions interchangeable with what is used in the Dynapro Radial 7816. The mount holes for the calipers are different though wont bolt to the same brackets.

The Radial clearance for a Dynapro Radial on a 11.75" rotor is 6.57" major advantage for tight wheel fitment. Also note the Dynapro Radial mounts on the same bracket as the Superlite with .020" difference in spacer height radially and 5mm offset difference offset can be adjuste with washer spacers.

Subscribed.

I'm very happy with my V8R 11.75" Dynapro setup, but I'm interested to see what you come up with for a potentially higher-quality caliper.

Installing kit today on Taxi. Sport rear with Sport m/c and prop valve. Testing this weekend.

https://cimg6.ibsrv.net/gimg/www.mia...7a9b9c9d91.jpg

What is the reason for the sport rear over the 1.8+mtuned?

In the past I've seen you recommend the 1.8 caliper on a sport rotor for cars without extreme aero.

Very cool. Are AP Racing calipers out of fashion these days?

Hmm. Jet nuts on the back of those rotors?

And I don't think AP has anything really suitable in a Dynalite-ish size.

What size rotor is that?

Afaik its only available in 11"

I have a full assembly on my desk here with dynapro 4 radial, V8R radial bracket, 11.75" rotor - based on Wilwood's drawings the Superlight 4 for 0.81" rotor would bolt up to this same assembly with just a 5mm change on the bracket offset (inboard).

Pad volume is a no-brainer, that's a commodity among the current landscape of BBK options. On rotor thickness I'm split. Certainly there's a list of reasons the thicker rotor is better on paper, but all reports/requests I get from endurance racers is focused on pad life. Wilwood economy 11.75" rotors don't apply, but assuming good quality rotor I believe even the 24hr guys are good on one set of rotors. Conceivably, a car with enough power and a long enough race could make a case for more rotor mass than currently available though.

For the life of me I can't figure out why the Miata aftermarket tuner supplier crowd didn't jump on the Dynapro Radial bandwagon years ago. I've had them on my car for over 10 years now. It was well over a 50% increase in pad and rotor life when I first bolted them on my car swapping from Dynalite 11" to Dynapro Radial 11.75" due to a combination of 50% more pad volume to wear through plus the better thermal capacity of the larger rotor and they still fit all the different 15" wheels I was using. It's the tightest caliper shape package of all the suitable calipers.

What rotors are you running?

I had a 4 wheel stoptech brakes on my Audi B5 S4. They were better than the big reds on my 993 turbo! Can't go wrong with that caliper IMHO. I remember reading about them at SEMA.

We have always preferred the NA8 9.4" rear when using an 11" front. Stoptech asked us to provide feedback on their 11.0/10.9" combination with hydraulic ratios and pad .mu bias tweaked to compensate for the mechanical leverage bias. We'll see how it works.
Looks bitchin anyway.

https://cimg1.ibsrv.net/gimg/www.mia...31db1eec8d.jpg