BBK suggestion

[aaronng]

They are KU36 50% tread left...

How old are they? If they are a few years old, then the compound would have hardened, eventhough KU36 starts out with a low 180 wear rating. Once hardened, the tyre grip will drop off very quickly eventhough you still have 50% tread left.

[ALPS]

oem brakes still more then enough for those roads unless your driving like it's a hillclimb championship event which 99.99% of the people here wont be.

Spoon calipers use the same brakepads as your stock calipers.

All i'm saying is that the s2000s OEM brakes are not fine for "ANY road thrashing". For those who do like to drive spirited and more than just a 'sunday cruise' on the mountains. i know people who have mentioned many times how the brakes fade in these circumstances.. I would even believe it if proven that the mountain runs put more strain on your car than what you would on the race track.

[aaronng]

All i'm saying is that the s2000s OEM brakes are not fine for "ANY road thrashing". For those who do like to drive spirited and more than just a 'sunday cruise' on the mountains. i know people who have mentioned many times how the brakes fade in these circumstances.. I would even believe it if proven that the mountain runs put more strain on your car than what you would on the race track.

Having been on both, I'd say that the race track is still harder on brakes because more heat is generated especially if you go non-stop for a 10 minute session (turns my new brake fluid black and pedal feels spongy. Goes back to normal after I bleed it out). However, I will also say that OEM pads are insufficient for mountain runs. That being said, a BBK is also not required for mountain runs. What is required are good sports pads that can withstand the heat and still deliver stopping performance at high temperature.

[ALPS]

very fair statement and i agree! you don't require a BBK for mountain runs or daily driving, and even if you do get a BBK, you need to make sure you have the better pads. But if you're already considering it, knowing cost involved. Why not? i'd go for a brake upgrade if i can justify my funds to go to it anyday..

Having been on both, I'd say that the race track is still harder on brakes because more heat is generated especially if you go non-stop for a 10 minute session (turns my new brake fluid black and pedal feels spongy. Goes back to normal after I bleed it out). However, I will also say that OEM pads are insufficient for mountain runs. That being said, a BBK is also not required for mountain runs. What is required are good sports pads that can withstand the heat and still deliver stopping performance at high temperature.

[aaronng]

very fair statement and i agree! you don't require a BBK for mountain runs or daily driving, and even if you do get a BBK, you need to make sure you have the better pads. But if you're already considering it, knowing cost involved. Why not? i'd go for a brake upgrade if i can justify my funds to go to it anyday..

Agreed, if it is a "want", then the decision is easy. Just go for it if the OP can afford it!

If it was a "need" where the OP was trying to correct a certain deficiency with his AP1, then it gets a little complicated. Since the OP stated he wanted to improve braking performance, it will be important that we identify what braking issues the OP is experiencing now. Otherwise he might end up in an ugly situation where thousands of dollars has been spent but the braking performance has not improved as he expected.

[whokid]

Thanks for all the suggestions, obviously propel have different opinions. Thanks for everyone sharing their own knowledge and expirences.

[aozora]

Sorry but why are s2k rotors prone to crack ? Can you back this up with some examples for everyone to observe


Remember that a BBK comes with slotted/dimpled and possibly cross drilled rotors as standard too ?

http://www.s2ki.com/s2000/topic/7448...re-than-usual/
Knock yourself (yourselves?) out. Plenty more threads on this topic available too.

Yes but I'm talking about an OEM setup
From what I understand, cracking mainly occurs from sudden changes in temperature, metal fatigue or poor metal composition. A BBK rotor setup will ideally be thicker/larger/be 2-piece to allow for thermal expansion and be able to handle heat better through improved cooling vanes making cracking less of an issue. I'm guessing if you over-engineer a setup, you could probably engrave hello kitty on them if you wanted to and it wouldn't crack (braking performance however...) But it also depends on the metal composition and how it has been cast. A lot of factors... probably better to speak to a metallurgist really for a much better explanation

Anyway this page explains some of the points better than I can...
http://www.urgedesigns.com/brakes.html

slotted rotors only alleviate the problem??

Yes and cross drilled even worse - I had an engineer explain it to me through diagrams (not directly about rotors mind you but how to avoid weak spots in metal structures) but I cbf drawning diagrams haha.
The best way that I can (poorly) explain it is to file out a small groove in a pencil. Snap it. It snapped along the groove most likely right? Now snap a pencil without a groove. Which one was harder to snap?
Of all the cracked slotted rotors I've seen, the cracks develop within those "slots" (or on 2 piece rotors, they seem to develop small cracks near the alloy hat bolts and/or through the slots). That's not to say though that you shouldn't use slotted rotors at all... just preferably not on a OEM S2000 rotor setup

[9large]

whokid, if you're just cruising the streets or doing spirited driving/mountain runs, the stock rotors are more than enough. It's a common myth that gets propagated. The only time I've seen rotors crack is at the track where people haven't cooled down or warmed up their rotors properly (read, gradually). The brakes gets a TON more load at the track than even fast mountain runs. There's no way you would generate that much heat on the road, and if you do, you need to take that kind of driving off the streets. And I agree with aaronng - if you just want a BBK, then go for whatever takes your fancy - it won't matter - but you won't need a stronger brake setup for road speeds and driving conditions. After several years of tracking, I can tell you the stock setup is quite strong, especially for a single piston setup. Also, if you want a proper BBK (not just Spoon caliper posers), then 8 +45 is not enough. Sometimes, spoke design counts too.

If your pedal feel is getting soft, try flushing and changing the brake fluid. If you want a different/better feel to the brakes, you can also try changing the pads or fluid. At the end of the day, your limiting factor is your tyres. I've used various brake setups over the years, and it's always disappointing when folks spend $$$ on the notion that their braking is suddenly better, when they haven't considered the car's whole braking system, and all they do is potter around the streets and pose.

. . .

Yes and cross drilled even worse - I had an engineer explain it to me through diagrams (not directly about rotors mind you but how to avoid weak spots in metal structures) but I cbf drawning diagrams haha.
The best way that I can (poorly) explain it is to file out a small groove in a pencil. Snap it. It snapped along the groove most likely right? Now snap a pencil without a groove. Which one was harder to snap?
Of all the cracked slotted rotors I've seen, the cracks develop within those "slots" (or on 2 piece rotors, they seem to develop small cracks near the alloy hat bolts and/or through the slots). That's not to say though that you shouldn't use slotted rotors at all... just preferably not on a OEM S2000 rotor setup

That is relatively true for rotors with channels/slots or holes drilled post-fabrication. The cracks typically form where there is less structural integrity - from the edges of the slot or hole. Your analogy would also be more correct if you had to snap the pencil by standing on it, not exerting a directed force. The slots are used to channel hot gases (and even water) from the surface of the rotor, not to accommodate rotor expansion.

[bennjamin]

Just another point

S2k Shares the same rotors and pads as ep3s , Dc5rs amongst a few - never heard of these cars having stock rotors crack at any degree ?!

[aozora]

That is relatively true for rotors with channels/slots or holes drilled post-fabrication. The cracks typically form where there is less structural integrity - from the edges of the slot or hole. Your analogy would also be more correct if you had to snap the pencil by standing on it, not exerting a directed force. The slots are used to channel hot gases (and even water) from the surface of the rotor, not to accommodate rotor expansion.

You'd hope that all channels/slots are in the cast and not post-fabrication! I would hope it's illegal to do so otherwise (although I hear of people machining the inner surface of their rims to increase offset... and also some drilling other studs in rotors/wheels to change stud pattern.. scary).

For reference, these rotors were only 1 track day old or so before they cracked (pic stolen off Vyet's old forgotten blog )... which also confirms that it's not a distribution of force issue either (At one stage people were saying that possibly the 1 piston caliper was not distributing the pad pressure evenly on both sides, but even with a 4 pot it still happens)

The outer edge to a very small degree would act as a cantilever though as I don't think the force exerted on the "pencil" in this instance is 100% even. But I get what you're saying? And yes I believe slots also help with the deglazing of pads.

Just another point

S2k Shares the same rotors and pads as ep3s , Dc5rs amongst a few - never heard of these cars having stock rotors crack at any degree ?!

I don't understand either, I'm not involved in other Honda communities so I'm not sure why it's an issue with just track S2000s (never seen it happen on a daily driven S2000)? I don't know if being RWD has anything to do with it as that's really the only difference? Or perhaps, the front hubs are slightly smaller and that plays into it somehow? I dunno - just throwing guesses now.
Locally, I know S2000 people seem to crack rotors faster if they're using R-spec tyres. And in the states, I don't know how much more popular the S2000 is over other Hondas for track use, which may explain why there's more notable cases?

Again this isn't to scare away people from using the stock setup. I know plenty of people on the stock setup with plain (myself included) and even slotted faced rotors tracking just fine.
I'd be curious to find out what the OP went for in the end?

[aaronng]

I don't understand either, I'm not involved in other Honda communities so I'm not sure why it's an issue with just track S2000s (never seen it happen on a daily driven S2000)? I don't know if being RWD has anything to do with it as that's really the only difference? Or perhaps, the front hubs are slightly smaller and that plays into it somehow? I dunno - just throwing guesses now.

From my understanding (trying to draw out whatever engineering knowledge that is left in my head after all these years), cracking across the entire rotor like in the photos is usually caused by severe temperature differences across the face of the rotor. To achieve such extreme temperature difference, you will have to be using very aggressive brake pads that will generate that sort of friction (which is what we all want, brake pads with high friction coefficient) and also be able to maintain that friction even at high temperature without fading (which is what we all want as well, pads that work from 200-800 ºC!). So if you go through all the cases where the rotors have cracked in this manner, we should find that a common denominator, which should be the very aggressive brake pads (metallic or carbon metallic), one-piece or two-piece OEM/street/sports rotors, combined with prolonged durations of hard braking (race track with many short-medium straights followed by tight corners, tracks that Honda drivers love).

Locally, I know S2000 people seem to crack rotors faster if they're using R-spec tyres. And in the states, I don't know how much more popular the S2000 is over other Hondas for track use, which may explain why there's more notable cases?

Tyres with more grip will allow more braking force to be generated because they won't lock up or engage ABS. So more temperature generated in the same corner compared with S2000 running street tyres.

Again this isn't to scare away people from using the stock setup. I know plenty of people on the stock setup with plain (myself included) and even slotted faced rotors tracking just fine.
I'd be curious to find out what the OP went for in the end?

My opinion is that the set up needs to match what the car is used for. Most of us track for fun and are not running in competitive events where we are willing to push the car to the limits where a misjudgement results in the car running into the wall. For those who want to push all the way to that limit, then the setup needs to match so OEM rotors or even sports brand rotors will be insufficient.

The combination of the pads, aggressive braking and high temperatures actually necessitate the use of rotors designed for proper racing purpose. Not the regular/mid-range stuff that we all buy.

[curtis265]

some good posts here guys