sixshooter

iTrader: (12)

When you say cheap 205's do you mean older street tires?

aidandj

iTrader: (5)

Cheap all-seasons. Hankook v2 Ventus I believe. I meant to say cheap street tires.

dasting

You're going to melt those tires before you get DTC60s in their happy zone, or just flat spot the hell out of them. If you're not expecting to out perform those tires, HP+ will probably work fine.

aidandj

iTrader: (5)

Will my stop techs survive?

sixshooter

iTrader: (12)

If looking at the PF's it would likely be the 14 in the front and the 97 in the rear according to OG's site. You can't push an all-season very hard or they get greasy as crap. You are approaching that power level.

DTC60 would be to grippy. You would lock them up often.

Maybe a DTC30 if you wanted a Hawk. You must match the compound to the tire.

aidandj

iTrader: (5)

I bet they will. I did 2 track days on R-comps last year and crashed on the second one. I am starting over with street tires and pushing them before I switch back to something grippier.

dasting

I took Stop Tech Streets to the Glen in a stock power miata on old RS3s and they held up fine for 30 minute sessions on NA8 brakes. The car wasn't fast though, I was running 2:30. That said, I think they're a fine match for beat all seasons. Your braking zones are going to be early.

aidandj

iTrader: (5)

Thats what I wanted to hear.

PatCleary

What are you looking to fix with a different pad?

I have StopTechs on my track/ autocross car and so far I've been happy. I know that they have enough torque to lock up a set of Rivals at least once. As I start running deeper into corners I'll want a more consistent, higher temp pad. However, until I reach that point I'm happy to save a hundred bucks a set.

OGRacing

iTrader: (1)

this..

I would be looking at the PFC 97 or 14 compounds. they would be a good match for some cheese tires like that. you will also get the consistency of a good race pad. the max temp for the 97 is around 1600*. so you won't need to worry about going too fast, and overheating them like you would with a street pad.
We also have the hawk 5.0 they caill for a max temp of 1400* and it is a street pad. might be something to try out.

OGRacing

iTrader: (1)

First off there are 3 ways to change brake tq. Rotor size, hydraulic advantage and pad compound.

With your car being all street duty we cannot run a race pad. You will be out of the needed temperature range to keep a transfer layer. Thus the pad won’t work properly. That combined with the iron in the pads, meaning brake dust will rust to your wheels. This will all be detrimental to a street car. With compound ruled out that means to increase tq we will need either a larger rotor, a larger piston, a smaller master cylinder or a combination of all three. For your car I would try going with the V8roadsters 11.75” kit. I would do that before messing with MC sizes. I would also try the hawk 5.0 compounds. They are tasked as a street pad that can take a beating. It would be worth looking into.



i'm going to share your message in the brake questions topic. i hope you don't mind.

OGRacing

iTrader: (1)

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


the image listed here is considered a 3nd form of deformation.


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.

OGRacing

iTrader: (1)

open to answer any new questions. Noobs allowed too.

tazswing

Sickness.

Hats and connecting points for floating rotors: I am trying to pick a front brake system for a full-weight MSM that will be seeing about 200whp and 4 HPDE/yr with a intermediate driver (me) and high performance street tires like R1Rs, etc.

There seems to be a big range in brake systems one can purchase. What I am having trouble getting a clear answer on is regarding the attaching hardware and number of attachment points between a hat and rotor and how important this dimension of the rotor becomes. Wiring in the hardware, check. But 6 vs. 10 vs. 10+ connecting points? Does it even matter for the light frequency I will see? It seems like it is a big deal since those bolts are transferring a great deal of energy.

Thanks.

OGRacing

iTrader: (1)

The attachment points are a big deal. It digs into the Engineering of said rotor, or at least it should. All decent available BBK’s for the miata have 2 piece rotors. The point they attach and the amount of attachments will affect the rotors ability to move with thermal expansion. 90% of the companies that make brake rotors will not take this into consideration when making a rotor. They will build a hat that fits as many rotors as possible. They do this so they will only need to offer 3-4 hats sizes. It’s a business decision not a performance decision. PFC will make a hat for every rotor they make. 1 this makes a very good working system performance wise. 2 It makes it a huge PITA to try and sort through thousands of part#’s to find the right one. What bolt pattern is best is clearly dictated on how the rotor itself is engineered. I cannot say that 6 bolt is better than 8 or 10 bolt.


What kit is right for your car? As a general rule of thumb I try to shove the largest rotor I can into a front wheel. Larger rotors provide longer life, better manners, higher tq, better modulation. When teamed with an aluminum hat they can be lighter than the original one piece rotor. V8 roadsters right now is making the best engineered brake kit on the market. I would like to see them run a floating rotor design, but right now they have the best.

Tim_Aus

Ok so over the last 2 days I have read all 19 pages, but from what I am going to ask I guess I have only taken in 1% of the information, so apologies in advance for asking something that has probably been answered 18 pages prior.

I have an NA8C track only, it is N/A with a measly 120hp at the wheels. I am trying to do one thing at a time, and basically everything I can before I pay someone lots of money to build an engine that will be around 200hp.

Now to get to my brake question before I go on to much further, is something like this Project Mu kit (not with the supplied pads), be worth the extra money over a 11.75 TSE/or the likes kit?

From reading I guess what I am maybe assuming is that the above kit might have more rigidity in the calipers?

Currently for my braking setup I have:
Front
Project Mu SCR Rotors
Project Mu Club Spec Pads
Rear
Stock NA8C rear rotors
Project Mu HC800 Pads

and if you couldn't guess the fluid brand...
Project Mu G/Four 335

I also have a brake booster brace (I think, that thing to stop the firewall flex) and braided lines.

Also have a splitter and GTC-200 wing and running R Compound tyres 205 - 225 R15 (changes between Kumho V70A, Toyo RR and soon Hankook F200)

I guess there is a second implied question above also, is there any glaring flaws with my current setup? (seems to work fine, but looking to future proof, and lets be honest, track bling)

Thanks for you time,

Tim

ThePass

iTrader: (3)

Ooh monoblock caliper..

11.8" diameter and almost 1" thick rotors.

But dat cost though - $3,000 USD

OGRacing

iTrader: (1)

When I first looked at your post I was thinking. “what the heck is all this project mu stuff?” then I noticed you were in Australia, then it all made since. The PU BBK does look interesting, But it does have some features that are not as good as a track speed/V8roadsters. First off it’s using straight veined rotors.

In this post (https://www.miataturbo.net/general-m...9/#post1227678) I covered rotor deformation. The curved shape of the veins in a rotor is an engineering trick to help prevent deformation. It strengthens the rotor. Also as you might already know 11.75” = 299mm. so the kits offered on miata turbo are the same size. I have no idea what caliper pu is using, so I can’t say if it’s a better caliper or not. At this point I would say the v8 roadsters kit would be the better buy. I would need to see the details on the pu caliper to curtain.


For the current set up. That you listed. It all looks very very expensive to me. I am not familiar with the exchange rate. The rotors are a straight vein design, for a high dollar rotor I would like to see curved vein for strength. But if the rotors are dirt cheap (easy replacement) that is something to consider.

I did call The USA dealer of Project MU. He was telling me that the only pad offered for Miata’s is the “club sport”. Basically it’s the double duty pad. In my experience, pads that do double duty are made with compromises. Anyone that has owned an endure motorcycle knows that; it sounds like a great idea but it sucks in application. For the record I owned an enduro motorcycle. It was a dog slow road bike, and geared too tall to keep traction in the dirt. Street race pads have a tendency to not work well when cool, and over heat easily when pushed. If your wanting to go racing, get yourself some real race pads. I’ve had some experience with the boys at PFC AU. Give them a call they might be able to help you out. Performance Friction Brakes - Disc brake pads, Brake calipers, Disc Rotors, Hats, Big Brake Kits

jko

Noob question here.

I'm on a stock powered 1.8 NA using OEM calipers and Napa 'spec miata' blank rotors with Carbotech XP10 pads front and rear. I keep having this brake 'issue' where after a 30 min session or two I will have a longer pedal, but little change in braking performance. The longer pedal will last for the rest of the day, but seems to mostly disappear over night, with maybe a few lingering effects the next day. I was always convinced it was boiling brake fluid, but whenever I bleed them there are little to no bubbles anywhere. I also switched from OEM brake lines to SS brake lines (thinking it was the rubber lines expanding) but there was little change in this behavior.

However, judging from your quote above, does this sound like a rotor issue more than a pad/fluid/brake line issue? Obviously I'm not too shocked judging from the quality of rotor I am using.

OGRacing

iTrader: (1)

I'm not thinking it's a rotor issue. a rotor issue will go away and come back during in between turns. if yours last over night i'm leaning towards fluid. i also think the heat is caused by the pad. i think your using too low of a tq compound, combined with some not so fantastic fluid. Lower tq pads have a tendency to get surrounding components hotter. the pads are in use longer vs. a high tq pad, and the heat has more time to leach into the caliper.

What pads are you using on the rear?
what fluid are you using?