Front big brake on turbo miata - enough ?
 

Hey,

I got front set of NB big brake: calipers, rotors and custom high perf pads.
Stock rear breaks.
Stock NA 97 booster and brake pump.

It is a +200whp miata, after I installed it all I feel the brakes are better at the end of the paddle, none to little brake on the first half of the paddle.

What do I need in order to get real solid good brakes ?

Thanks !

ESL translation needed.


Bleed the brake fluid at the front and rear calipers again.

Do you mean that you purchased an NB sport front caliper and rotor, a M-Tuned Corrado BBK, an 11 inch Wilwood BBK, or the 11.75 inch Wilwood BBK? You know that NB and NA 1.8 cars had the same brakes unless the NB had the "Sport" brakes, right?

We really don't need to know what "custom high perf pads" are, either. Details certainly aren't important. All pads are equal. Some are just more equal.

I got front NB "sport" brake:
(that consist of)
2 front calipers
2 front rotors
and custom made pads from a local brake shop, they use high performance (high temp) materiel on the original pads.

What is ESL ?

ESL = English as a Second Language

So using a larger diameter caliper piston without going to the larger diameter master cylinder? Yes, you will need to push the pedal much further to use your brakes now. The caliper needs more fluid than the old one but you are still using the smaller master cylinder to feed them. Since the rears haven't changed, they might start braking first.

My next step ?

Adjustable proportional valve ?

Anything else ?

That's not the problem. If you want shorter pedal travel then you will need to change to the larger master cylinder.

I want better braking, my 2012 corolla brakes much better, I would like to get at least closer to that braking level...

Then change back to the stock front calipers and buy more aggressive pads for all four corners. You are using stock style pads on the rear and I assume you had stock ones on the front before this change. Yes, they would suck at 200whp.

What tires are you using?

Here's your problem, most likely. Random unknown pads with random mu and random compressibility. Replace with actually good pads that are targeted for your application.

So, what is your application? Street-only? Auto-x? Track-only?

Oh, and so I stop having a seizure, it's a brake pedal, not paddle.

upgrading the fronts brake system without touching the rears can throw off your brake balance. Possibly shift it so the front wheels lock way ahead of the rear which could decrease your overall maximum braking acceleration.

Brake balance should be considered. An adjustable proportioning valve is considered a "band-aid" method of brake balance.

What is your definition of "better"? Are you basing this off of pedal feel alone? Are you doing 60-0 stops and timing them? Do you just want brakes that feel good on the street, or ones that can handle high heat on the track?

if i was upgrading stock brakes, i'd start in the rear personally.

I feel that some clarification of purpose would be helpful here. Is this vehicle being used for competition (eg: multiple-lap races at high speed on a track), or is is a street / AutoX car?

If the former, then larger brake systems can be helpful in that they have the ability to absorb and dissipate more heat than their smaller siblings. Thus, brake fade is reduced. By the same token, pad compounds rated for high temperature are also less susceptible to fade at extreme temperature, albeit with the caveat that they require higher-than-ordinary temperatures in order to function properly.

For a street-driven car, high-temperature pad compounds are generally worse than stock. They do not perform nearly as well when cold, where "cold" is anything less than glowing red-hot.

Likewise, the stock brake system on a 1.6 Miata is entirely adequate to the task of stopping the car quickly from its redline-limited top speed of about 130 MPH, several times in a row, with no ill-effect. In this context, HP is completely irrelevant.


There is a simple test: Can you deliberately lock the brakes (or invoke ABS, if so equipped) at high speed by pressing on the pedal as hard as possible? You should be able to.

If so, then your braking system is not the limiting factor which is preventing your Miata from stopping at least as well as a 2012 Corolla. That would be where you start looking at tires, alignment, suspension setup, the driver, contamination of the braking surfaces, etc.

If not, then something is broken, and slapping on parts from other cars isn't necessarily going to fix this. Maybe you have air in the brake lines. Maybe your power brake booster is faulty. Maybe the master cylinder needs to be rebuilt.




Also, I'm going to repeat the following point, as it merits consideration perhaps more fully than anything else which has been said here:

Beyond the fact that I have literally never heard of a local brake shop custom-manufacturing brake pads for any application, the use of "racing" style brake pads rated for higher-than-normal temperature will, all else being equal, result in poorer braking performance than OEM-style pads in everyday use.



https://www.miataturbo.net/attachmen...ine=1418924965

It does happen. There's a guy in the UK, (MX5 specialist / breakdown recovery company), whose unit is nearby a motorcycle modification company who make their own brake pads, they started chatting and now we have a source of very very good fast road/track pads.

They're comparable in performance to Axxis Ultimates which are thought of pretty well over here, they dust far less too which is a bonus.

Apparently development was interesting, 1st set plastered your face to the windscreen but lasted literally 20 miles. Next set nearly caused an accident, pressing the pedal achieved virtually nothing in the form of slowing down.

Thank you all for the info, let me give some input.

I use the car on weekends for hard driving (street/mountain side).
I use 205/50/15 Toyo R1R tires.
I understand I should use pads that are meant for my application (or at least try them) I can get "Endless mx72" here.

I got a suggestion on miata.net to take off the proportional valve in order to allow some (more?) rear braking.

I will try a better brake fluid while carefully bleeding the system.

I will test my corolla vs miata braking - with hard numbers.

Sorry for the paddle thing :)

I'm still kind of curious as to whether the brakes were working improperly or inadequately before the conversion was performed.

On stock brakes after fluid refresh there were two problems:
1. brake fade to almost no brake after hard driving in the mountains. very bad smell when that happened and very frightening and dangerous.
2. braking was not very sharp.

The 'sharp' thing is initial bite. This is a feel thing and doesnt translate to performance.

As for smelly overheated pads, your pads suck more than Gianna Michaels, buy application specific high quality pads and fit them to new or machined rotors.

BOTH ENDS.

1. Put stock front calipers back on to restore balance and proper pedal travel distance
2. Buy some Performance Friction PF01 pads for front and rear from OG Racing (vendor on this forum)
3. Enjoy your car.


The problem you describe is "pad fade" and it is a result of using a pad that is not made for high enough heat. Be careful if you try another high heat pad because some of them don't work at all when cold. The PF01 works like stock when cold and work very well at racing temperatures without fading. They also don't require special procedures when you first use them like many high temperature pads do. The PF01 pads will also be very easy to control with street tires. Some high temperature pads get very grippy and will lock up tires too easily but the PF01 will not.

Good luck.

I went on the OG site. The PF01's are being replaced by a PF11. Steve, do you, or have you, run these on both street and track?