aidandj

iTrader: (5)

Because my pads only cover the upper part of my rotor. Mini Cooper rotor. Dynapro caliper.

OGRacing

iTrader: (1)

that's not advisable. What is happening is that your going to have a super heated outer surface, and a cooler inner surface both sharing the rotor face. this will cause the rotor to thermally shock itself. are there any calipers out there that have a larger swept area?

aidandj

iTrader: (5)

Probably. This has been working for me well so far. Its not the perfect setup out there obviously, but the cheapest one I know of.

codrus

You have dynalites, right? It's not the calipers that are the issue, it's the cheap Corrado rotors.

--Ian

aidandj

iTrader: (5)

Dynapro. Mini cooper rotor.

OGRacing

iTrader: (1)

This is what your rotor is doing. you're seeing the cracks along the inner ride of your hot area. All of those cracks are from thermal shock. you're going to be hard pressed to find a rotor that will live under those conditions. under closer observation the "cracks" are actually Pits. The rotor is flaking off and falling apart. with the rotors not being slotted i'm guessing that material is being imbedded into your pads. when you put on fresh pads do they perform better at first then slowly "fall off" as they are used?

aidandj

iTrader: (5)

Not really. I've had good performance with these for a while now. Went through a full set of pads on these rotors, probably should replace them.

Savington

iTrader: (31)

How is that any different from the difference in temperature between the unsurfaced area of the inner hub and the surfaced area of the rotor? There is no material difference, it's just a machining difference.

Todd TCE

Just for the record: the size of the piston you show being measure is not likely the actual size of the functioning bore. Surprised someone hadn't mentioned that...

What you see is the smaller diameter (most commonly) of the step for the dust boot. The only way to properly measure the piston or bore is to extend it and remove the boot.

*Unless you had firm info from a reliable source and not the dial caliper shown of course.

OGRacing

iTrader: (1)

Savington,
A few differences, Rotor face has much thicker material, also the rotor face has cooling fins. The straight vanes do work, just not as well as curved vanes. Both of those factors help the unused swept area say cool (as compared to the area being used by the pad). To your point, The thermal shock does still happen in the hat-to-rotor-casting area just to a lesser extreme. That's why 2 piece rotors are preferred and it's also good to have the mounting tabs as small as possible.

mekilljoydammit

Was thinking of this on the drive in this morning... how much difference in something like a Miata application do multi-piece pistons like Wilwoods Thermlock pistons or the Performance Friction rocket nozzle insulator pistons make? Or are they really more of a factor of trying to get every last bit out of the setup?

OGRacing

iTrader: (1)

if you're not getting heat into your fluid. Almost no difference at all. if you are having caliper heat issues, it could solve them. think about a Fwd car. all the braking is done on the front axle. all of my conti FWD cars need to take drastic measures to keep front caliper temps down. almost all of those cars benefit from an insulator. on balanced, low power, cars like a miata. the braking balance is well distributed. heat isn't much of an issue.

dasting

This seems like in theory, you're probably right, but in practice, especially for driving at DE day levels, it doesn't matter. I have the m-tuned rear kit to use 11" rotors with the stock calipers, and it leaves rotor area untouched by the pads, and I haven't had any issues in probably a dozen or so track days with them driving a 1-2 seconds faster than SM record times. Lot's of people have that rear kit, and I've never read of issues.

OGRacing

iTrader: (1)

here you go.

aidandj

iTrader: (5)

Different kit. That is a rear solid rotor. Which btw is the exact same way that mazda designed it. On the NA8 brakes the pad does not cover the entire surface of the rotor. I can find a picture later.

Mine is a front vented rotor. That is vented all the way through.

Next track day is my girlfriends first track day. I bought new front rotors. Other ones went on the shelf to be used later.

OGRacing

iTrader: (1)

have fun, don't scare her... or show her you're scared. :P

joshbot007

I got one. So I really want to upgrade my breaks to help with the power that will be coming from the turbo. I have rpf1 15x7 wheels and was told that I can not fit a big break kit with these wheels. I was OK with this at the time of purchase but now that I want bigger breaks I'm kind of in a struggle. So I guess what I'm asking is that without going to a big break kit what is the best or most reasonable break setup (including calipers and breaks if need be) that I can jam (doesn't have to be jammed it could be stock size i'm just trying to achieve good breaking power) in underneath these wheels that will give me sufficient breaking for a 250 whp car.

Chilicharger665

iTrader: (2)

What are "breaks?"

turbofan

iTrader: (1)

This should give you the breaking power you're looking for.

OGRacing

iTrader: (1)

the boys are giving you a hard time lol.

Call up V8 Roadsters. I've been all over their brake kit, and they have taken my advice on increasing the performance. IMO they offer the best kit on the market.