18 replies to this topic

[miata4me]

We have our spec Miata and I know we can't change the braking system on that car.  However, we recently picked up a 91 Miata that will be used primarily as a street car and occasionally will also be used on the track.  I'd like to upgrade the brakes on this car without spending a ton of money.  Is there a way to add larger rotors/calipers/pads for a reasonable price?  I see that Wilwood offers a kit, but I was hoping to not spend that kind of money on this project.  Any suggestions?

[callumhay]

You could look at the 94-97 brake swap. The caliper brackets from those years fit the 90-93 calipers. You need bigger rotors and whatever brake pads you want. Also add stainless brake lines. Even an after market brake proportioning valve. Search for the graph on line that compares the proportioning system from different years and I think you'd conclude that the 1.6 needs some help there. While you are at the brake rebuild, maybe rebuild the calipers or replace to have everything working well. Lube the sliders!

[davew]

To put the 1.8 SM size brakes on the car you will need:

Front calipers (complete with brackets)

Front rotors

Front pads

Rear caliper brackets (The caliper itself is the same 1.6 vs 1.8)

Rear pads

rear rotors.

 

Brake hoses are the same, I would upgrade. Master and booster are the same.

 

You could also upgrade to the Sport brake package as found on VVT cars. You will need to change calipers, pads, rotors and brackets on all 4 wheels. Along with booster prop valve,and master cylinder.

 

Or there are assortments of BBK's available from Flyin Miata, Goodwin, Moss, etc.

[miata4me]

Is this the Sport brake package that Dave mentioned?  Seems to be, but it never hurts to confirm...

http://treasurecoast...sport-cars.html

 

I don't know anything about Treasure Coast Miata.  If there is another source I should consider, please let me know.

[MPR22]

Just use better pads. hawk makes a streatable pad that can handle track days.

[Johnny D]

[callumhay]

I can vouch for treasure coast Miata. Bought stuff from them ..Never any isdues. Wes and the crew there are racers too.
Cal

[Mark McCallister]

FWIW, it is not my impression that there are any significant performance gains to be made in a larger kit, unless terminal straightaway speed is increased with a turbo or supercharger kit (in which case plan on cooling system upgrades), or an engine swap of some sort.  Stock 1.6 brakes are more than sufficient to flat-spot tires even with SM7 rubber.  Race brake pads for track days, stainless braided lines, and new fluid should otherwise be sufficient?  You can read up on various mods for higher-power miatas over on http://www.miataturbo.net/ ,  miata.net, etc. The vendors mentioned above will definitely have guidance.  Good luck, nothing better than playing with Miatas.

[Danny Steyn]

FWIW, it is not my impression that there are any significant performance gains to be made in a larger kit, unless terminal straightaway speed is increased with a turbo or supercharger kit .

 

Finally - thank you. Miata's are over braked. You can flat spot any standard tire at any time with any brake pad, some pads are way more prone to flat spotting than others. This screams that better brakes are not needed. 

[Ron Alan]

"Big Brakes"...about the biggest waste of money you could every spend on a street Miata! As mentioned...the limiting factor is the grip of the rubber to the pavement! Pads will change the feel and pedal pressure...not destroying your tires will be a challenge with any stock set up!

[miata4me]

I do plan to upgrade the powerplant to a 13B.  I know some will consider this to be blasphemy, but at least I am sticking with a Mazda engine...  My son and I have a 20B in an RX7 and it is an absolute beast.  It would be so much fun to have 13B power in a Miata.  Yes, I know there will be challenges, but the kid and I will have fun with it for sure.  With this upgrade on the horizon, I was thinking why not upgrade the brakes now?  His spec car is a NB.  Having run that in races and now just having run the NA at a local track day, he feels the NB brakes are significantly better.  I guess it could just be the pads.  I appreciate everyone's input!

[callumhay]

I went from driving an NA to an NB and found the same. Some of it may be inexperience on my part but with the NA I felt like the responsiveness was just duller..Or even not as connected to the car as it is in the NB.. I think the difference lies in the size and type of the pads, rotors and the proportioning of the brake system. I think from memory both front and rear brakes get the same pressure to a point and then the percentage of front to rear balance changes after that ..And this figure is different from year to year. The advent of ABS is also a factor to consider in why it changed. But I think that proportioning is probably better in the newer cars than it was in the NA and that factors in to driveability. Correct me if I am wrong, but if anything less than 4 wheels lock at the same time, then we are not at 100 percent threshold?. Locking is going to be a combination of pads, rotors, proportioning, weight transfer in the car, tire grip and driver. if one or two wheels lock, then there is potentially more to gain in the system. I'd leave clarification from those out there with more experience than me, but I do think that in the NA 1.6 that the proportioning of the brake system is an area that could be looked at to improve the car for not much money. I'm not talking about parity, just trying to find an explanation for why your son thinks the NA had a different braking response.

[davew]

The NA brakes feel different from the NB, because they are different.

 

Think of the brakes as a lever. NA rotors are 9" diameter, 4.5" radius. NB brakes are 10"/5". That is an increase in leverage of 11% on the radius. Add that to the larger pad area and you should have brakes that feel different.

 

I know, brakes actually work off of kinetic (heat) energy, but the visual analogy works.

 

Bigger brakes may or may not stop the car better. But they will change how the brakes feel, how long they last and how cool they look through the wheels.

 

If you add much more power to the car, you will want some form of updated brakes. Especially if you are starting with 1.6 brakes.

 

Dave

[luvin_the_rings]

A quick note about the difference between racing brakes and street car brakes: 

 

A purpose built race car will have two master cylinders, one for front one for rear.  The brake pedal is connected to a balance bar which, when turned, can adjust the brake line pressure on front and rear system.  This is not the case with the Miata or any car built for road use.  This is also completely different than using a proportioning valve. 

 

A proportioning valve doesn't actually change the brake bias in the way many people think.  When the brake line pressure is below the set pressure on the valve, the pressures are still equal front to rear.  Once the pressure of the system reaches the set pressure of the regulator, the pressure in the rear stops increasing.  However this also means that the difference in pressure is also increasing as pedal travels more.  This means that brake balance is now a variable based on pedal pressure, which can good for Motorsport, but may hurt reliability on the street.  

 

In short, a proportioning valve can be a useful tool for a racer, but it also adds in problems.  So It's important to know how it works so that you can maximize your gains while accepting the handicaps that it gives.  

[Bench Racer]

A primary orifice and floating orifice.  The two orifices feed to diagonal wheels RF/LR; LF/RR.

Gee, the left coast 1990 Miata brakes must be different than the Midwest 1990 Miata.      Just saying, check your brake lines and see which wheels they go to.

[davew]

Luvin, you are wrong. The lf/rr vesus rf/lr brake setup is only used on front wheel drive cars. Commonly called the X brake due to it's first big usage being on GM X-body cars back in the 80s. Chevy Citation, Buick Skylark etc. The X design was needed because on a front wheel drive car, if you lost front brakes, the tiny rear drums of the day could not stop the car on their own. So the engineers designed an X system that always kept one front wheel usable.

 

On a Miata, we do not use the X system. 

[luvin_the_rings]

edited. 

[William Keeling]

to increase braking I just use the car in front of me

[davew]

8 wheels stop and turn better than 4