Is a sport brake upgrade worthwhile on a '99
 

I've been looking at some brake upgrade options to go along with adding boost soon. I'm wondering if and upgrade from '99 base brakes to the sport brakes is going to be worthwhile or if I should wait until I can afford a Wilwood kit (or just forget about it and stay stock until stuff starts to come up short). Budget is pretty tight, Wilwoods would be a ways off. It seems the stock brake upgrade is more common on the NA but haven't seen much talk of it for NB. Car is primarily a DD with plans for occasional AutoX/HPDE use.

Additionally, I'm running an older FM/AGX suspension which the previous owner installed. Would you put higher priority on a brake upgrade or suspension upgrade?

Suspension. Get good pads and lines for your current brakes.

hold

It's unanimous (so far)!

Like everything in braking the only right answer is “it depends”. Most of the time I look for the chassis’ behavior to tell me what the braking wants. This time I’m going ask you what you want. Before I get into that lets review there are only 3 ways to increase brake torque, (hydraulic advantage, rotor diameter, pad compound). The sport brakes are an improvement over the 1.8l base brakes. They have a larger rotor, larger pistons (more hydraulic advantage) both will help produce more tq. That being said we have built many spec miata cars to have excellent brakes and superb stopping ability. class rules dictate that the cars need to keep the stock 1.8l brakes. We increase the performance out of those systems by changing out the pad compounds. If you’re looking for better performance the simple answer is yes, get the sport brakes. If you’re having a problem, replacing the system will fix that problem like throwing a hand grenade into a closet to kill a spider. Do keep in mind that pads (compound) make up for a lot. You can spend a ton of money upgrading your system. If you go cheap on pads, you can be installing a worse performing system. The 1.8 and 1.6 brakes all have a wide selection of pad compounds. Those compounds have been proven to work well in racing and street applications. So let me ask you this , are you currently unhappy with your brakes, if yes then why? if you are worried about finding the limitation of you brakes no worries. The factory brakes can take a lot. The time I would step up to a v8 roadsters 11.75” kit is just before you start adding power.

Johnny knows whats up!

Like he said, the sport would be a great improvement.

If I were in your shoes I would get the sport brakes, good pads, slot rotors or oem quality, and SS brake lines with higher temp fluid (Whats that blue stuff again?)

In an old civic my ex had, we did just that. New oem rotors, hawk pads, ss lines. Stopped on a dime for a DD.

^erm, that's not exactly what he said.

More like switching to Sport brakes at this point is just throwing parts at a problem that OP doesn't fully understand, and that likely good pads will give him the braking power he needs, allowing him to save more for the eventual upgrade to the 11.75" kit.

the only problem with sport brakes is pad selection. all the top level race pad manufactures overlook the sport brake sizes.

^this. I'm having this problem currently. Selection for pads on the sport brakes is very slim.

Yup. Wish i hadn't removed my 1.8 brakes.

ah, :bigtu:

I re read the post.. :squint:

Also was not aware of the limited pad issue.

Thanks guys, I kinda figured this was the direction it would go. I'm not unsatisfied with what I have now, I was mostly wondering how adding power is going to influence that. I'm running stoptech pads now and I know there are a few steps up I can make in terms of pad quality to increase performance of my stock system. I wasn't aware of the limited pad availability for the sport brakes so I that's another strike against them.

I suppose I'll see how things perform as is and experiment with pad selection when I feel it's necessary. Then I suppose when/if I feel like I've maxed out the stock system I can look to upgrade to those big beautiful 11.75's.

+1, I bought a set of sport brakes, front & rear, calipars, brakets, master, booster and prop. NASA changed the classing before I put them on, they went from no points to three points.
But when I started looking at the available race pads, there were very few, and not the ones I'm currently using on my standard brakes.

As long as you have more brake than tire, (and they don't fade) you have enough brakes.

Get good pads, lines, and fluid. Get some front brake ducting going and they will work well for a long time. Save the 11.75's for when you finally know that you need them.

Yes but let me clarify.
brake fade is a red flag that something is wrong, broken, or about to become a crash. Most of the time with new drivers the fade comes from exceeding the operating temperate of the pads. new track day participants get a helmet but forget about adding race pads. they head out on track with a street pad from "O'auto parts" that has a MAX operating temperature of 600*. for the riggers of road racing you need a pad that has a MAX operating temp in excess of 1000*. any race pad (hawk, padgid, PFC, so on so no..) should be able to obtain this minimum.
you will know when you've overheated out a set of pads because they will never operate at the same Mu (coefficient of friction)



there is also fade from fluid, and rotors.
I got the opportunity to test out the Exomotive XP-5 car. this is basically a LS3 powered buggy. This particular chassis was outfitted with Flyin miata’s Little-Big Brake Kit. Going into the hard braking zones I was getting fade from the rotors (EBC brand). In the motorsports world fade is also called “long pedal”. Going into the all of the braking zones the first ½ of the stop everything seemed fine. The 2nd ½ of the stop the pedal would drift to the floor. That’s why I wasn’t attacking the corners ( enter my best race car drivers excuse). When a rotor gets hot it will deform. Dependent on how it was engineered it will grow. That growth or thermal expansion will result in a deformed rotor. “deformation” comes when the brakes are in a dynamic state. there are many forms of deformation, the first form of deformation it will look like a cone. Brake guys we call this “coning” and it’s a huge source of brake drag in the system. The 2nd form of deformation it will start to look like a cowboy hat

https://scontent-atl.xx.fbcdn.net/hp...64&oe=55D72258
the image listed here is considered a 3nd form of deformation.

https://scontent-atl.xx.fbcdn.net/hp...58&oe=559970C9
Depending on how a rotor is engineered to resist deformation dictates at what temperature it will deform. The rotor listed above was from an autocross. It’s on a jaguar XK. as you can see this rotor has curved vanes but still deformed AT AUTOCROSS TEMPERATURES.

IMO i am not a fan of Wilwood or EBC rotors. they all seam to be built to a price, and not to performance. If they come out with something new i will give it a look but nothing on the market has impressed me.

Boiling brake fluid can create a Long pedal too, fluid boils when it gets hot. Most race fluids have a average boiling point of 450-550* . Generic DOT4 from “advanced AutoZone” will boil around 300-350*. Most of the time when a fluid boiled with a OEM caliper it heated from trapping superheated air coming from the rotor. Vehicles like the Charger, Challenger, 370z, g37 are notorious for the calipers heating up. Generally speaking In a Motorsports caliper the heat will enter the fluid by traveling through the piston. so solve this we ether run a higher tq race pad, or install piston insulators.

We knew the xp5 was having rotor issues because the long pedal would go away, and return. If it was a pad overheating the friction produced by that pad would steadily decrease. When fluid boils the performance will come back faster than cooked pads. With heated fluid the performance of the pedal will stay long to a point. The bubbles from boiling will stay in the system. The pedal will continue to stay long until you purge all the bubbles.

i'm going to share this into the "does anyone have any brake questions" thread

Thanks Johnny for dropping some serious knowledge!

i do my best to help.

My setup: Sport fronts, 1.8 rears, Carbotech XP10 front, XP8 rear. 2-1/4" brake ducts in front. Car is purely a track car, 145-150whp, 2200lbs, street tires and r comps a few times a year. Lap times are typically very near or below miata challenge lap records at most tracks. Most track days are 80-105 ambient temperatures.

100's of laps with this setup and i have never experienced any fade... and I don't mean like, never experienced significant fade... Not once has the engagement point ever moved any perceivable amount. Grab point has been the same each and every time I go for the brakes.

I get about 50-70 sessions per set of pads (12-14 track days) and about 3k street miles out of a set of fronts. Double that for rears. I don't use the brakes often but when I do, I use them like a man. I experience some pad taper but not enough to justify switching to an aftermarket caliper.

YMMV I suppose. I venture I could throw another 50hp at these pads and not see very different results on top of what I see now. I will most likely find out soon enough.

when you do notice "fade" where is it.. in relation to the braking event? also where on track are you? is it late in a session, at the end of a long straight, after multiple rapid braking events?
oh and please put your answers into this thread. i dont want to mud up the forum. https://www.miataturbo.net/general-m...estions-81577/

I simply don't experience fade... ever. I know I sound like i'm being a blowhard but i simply don't. I just finished a day at chuckwalla and I did 12, 20+ minute sessions in 105 degree ambient (143 degree surface temps) and never once had the pedal fade at all. Seriously, not once.

And this isn't a singled out event. I have never had these fad on me. Even when we were doing a 90+ degree day at the ACS roval or a 103 degree day at WSIR... the pedal has never moved off of it's typical engagement point.

More parts I forgot to list: willwood 1" master, motul rbf 600 and stock 99 booster.

Edit: I should add that I wouldn't expect to experience fade based on my data. I use color changing brake temp paint on my rotors and calipers. The outside edge of my rotors seem to get up to about 900 degrees, calipers seem to peak at about 500-600. This means I'm well within the temperature envelope of the XP10's.

oh, my mistake.

So what i'm hearing is that i need to move off of these damn EBC Yellows and just get Carbotechs like a boss so i can be like Eric.

And James should ditch his AGXs for some Swank Force Racing Zyduhs.

Haha I'm just suspicious native caveman that collects data. I know just enough to be dangerous and make the wrong decisions.... as such I just spend a lot of time on track and take meticulous records while doing so. Everyone's experience is going to be different. For example, less experienced drivers are going to brake earlier, longer, with varying line pressures (up, down, up, down) and drag the brakes further into the corner.

I've experienced this myself with i turn the keys of my car over to my father when he comes to visit and do track days in my car. Fortunately for me it gives me alternate data points to see what happens when you're doing it wrong. He's a gold watch wearing corvette/camaro guy... so he drives the miata like an amateur.

As with anything YMMV. I'm too dumb to listen to anyone else and take their word for it. I just put stuff on the car, beat hte hell of out of it, and record what I see.

carbotechs perform well but are expensive. most of the Continental teams that tested with carbotecs found that they wouldn't make it to the end of a 2 hour race. also in the 2013 season they had a high failure rate (material delamination). heck some of the mx-5 chassis where having a hard time making to the end of a race with padgid yellows. Our driver liam dwyer car (freedom auto sport) was campaigning for a class win at seabring this year till his car simply ran out of friction materiel. you can watch the replay and see the car missing a lot of turns and shooting into the grass. We where finding that the PFC race pads would have 2x the life. that's why i say carbotech are expensive because you'll need to buy two to go the same distance.


here's a video from Kevin Parlett. Crewman for a PWC team. he's also a driver for carbotech. had one of the pad failures captured on video.

So much want, so little monies!

Haha no not 949 Xidas, but the old 'bilstein shocks with ebay coilover sleeves' setup. They seem to be the go-to cheap racing suspension.

Ah, I see, my newb is showing. It seems some research is in order!

i'll warn you right now about the afcos :crx:

No problem, read through this thread: https://www.miataturbo.net/suspensio...-thread-78451/

Pretty neat, but PFC not available for my calipers. :( Le sigh.

You can make them fit. Just a bit of grinding.

EBC yellows have a heat rating to 1600 degrees F. I think that they have a lower coefficient of friction compared to some other pads so they might not feel as aggressive. I think the front Cobalt pads used in Spec Miata are only rated for 1200 degrees F.

"Not feel as aggressive" accurately and completely understates their street performance.

I'm hoping something is actually wrong with my brakes, because these things are sketchtastic with what little heat you get in your brakes during street driving.

Many "race" pads have very poor friction when cold. Cruising on the freeway for extended periods is the equivalent to supercooling your brakes, and it's no wonder that the pads have no friction to offer for the next panic stop.

One of the biggest selling points of the PFC line is that they are a full-fledged high end race pad, but also have decent friction even when cold. You don't find that everywhere.

What uses are you trying to cover with your pads? Street, autox, HPDE, race? If you can't get PFC's for your calipers, you may be better served with one of the less extreme track pads which do offer decent low-temp friction - Carbotech XP8, Hawk DTC-30, Porterfield R41 - all of these offer at least decent friction when cold and don't need 300 degrees before waking up, and they all have fade resistance above 1000 degrees.

Any of those will be worlds better than the EBC yellows on the street. Monitor brake temperature at the track to see if the temperature range of the pads above will work for you.

-Ryan

Street, autox, HPDE.

Carbotechs are the right answer i do believe, and i have a spare set of new rotors. I'm just gathering info now for when the rest of the car is sorted and get some miles on it. :)

Run from EBC. They make the biggest joke race pads ive ever seen. They say its rated to 1600 but I wouldn't believe it. Ive seen their stuff fail after being used for only a few laps. Keep in mind too that maximum pad temperature doesn't mean too much in the grand scheme of things. As long as you have a pad thats raded for 1000*+ youll be ok for hpde's.

I've heard from some of the fast guys in colder areas who were trying to run Carbotechs on the street that they were chunking and failing prematurely under street use.

I believe this was in reference to XP10/12, not XP8. I have no personal experience with said issues and have known local guys to street drive XP10s without problems. But down here it's always hot, and I only ever drove to/from the track on XP10s back when I used them.

-Ryan

I've street driven the XP10s down into the 30s without issue.

To the OP's question, yes. 94-00 brakes are good but at stock car weight and above say, 140whp, you start to need some pretty high temp pads with an expert driver. Sport fronts will give a better pedal and pad life. Carbotech offers them in riveted but least they ofer them. For most other Miata pads, the have a mold that allows a full bonded pad, no rivets. That said, we have won a few national championships and set a pile of lap records running Sport front, 94-00 rears. XP10/XP8 with a 1" master usually. Much above 170whp and an 11" Wilwood front setup starts to make more sense.\

You can actually get tiny NA6 brakes to stop a 2300#, 140wh HPDE car, they just feel like crap and taperdestroy pads in about 3 sessions.

Yep. BTDT, although I'd rather have not. 2400lb PTE car, "139whp" (145wtq), stock 1.6L brakes. It takes good ducting, mega-expensive fluid (Castrol SRF), and constantly flipping the pads to combat pad taper, and they feel like shit, and they wear very fast, but the car stops hard.