BoneHeadOtto

Im looking to replace my rotors with slotted or just plain flat and was wondering if there were any lightweight rotors that were recommended. Back in the day when i had a WRX i found that DBA rotors were lighter than stock. But im having trouble finding this information for the S2000. Are there any recommended rotors that are lighter than stock? Seems like a reat way to reduce unsprung weight.

gptoyz

Girodisc for 2 piece otherwise nothing better than stock

afzan

Stoptech makes 2piece also

BoneHeadOtto

Are 2 piece less durable and are they lighter? What is the advantage to two piece over a single piece? I guess its for track days and its less expensive to replace part rather than the whole? Or are there other advantages such as different materials for the disk and hub thus weight savings?

zeroptzero

less chance of cracking if you track your car, not sure if there is a huge advantage for street use, but any weight savings is a good savings, if money is no object.

gptoyz

Here are the benefits of a 2 piece floating rotor:

#1 reduced unsprung mass
#2 reduced rotational inertia
#3 rotor ring is allowed to float between the caliper which reduces caliper drag
#4 rotor ring replacement savings as opposed to buying an entire rotor (this isn't really applicable since s2000 factory replacement rotors are dirt cheap)

In terms of cracking this is really going to be more of a function of the rotor's metallurgy and the total heat generated in the braking system.

In all practical application, unless you have $700 burning a whole in your pocket, there's a whole bunch of other places to gain significant improvements of the marginal improvements of a 2 piece rotor.

BoneHeadOtto

so does anyone have any data on the weight and the savings? Considering how exensive it is to get lighter wheels i thought i might just pay attention when changing my rotors and get somethhing that is a few lbs lighter. Im having issue finding this information. I see this thread here but cant find the stock weight. https://www.s2ki.com/s2000/topic/939...s-aftermarket/
I think there is a real potential to save 2 lbs on the cheap here

BoneHeadOtto

ah ok it appears the S2000 rotors are already reasonably light. I was expecting 15-17lbs but they are apparently 14.5 so not bad. Other brake rotors look to save a lb at most
http://www.stoptech.com/media-center...or-honda-s2000

gptoyz

In summary this is what happens:

OEM S2000 rotor vs X-drilled rotor, 1pc:
while lighter than the oem rotor, you reduce braking performance and increase the chances of cracking the rotor

OEM S2000 rotor vs X-drilled rotor, 2pc:
while lighter than the oem rotor, you reduce braking performance and increase the chances of cracking the rotor, rotors will probably cost $700

OEM S2000 rotor vs slotted rotor, 1pc:
minimal weight loss, increased pad wear, increased cost over stock rotor or stock replacement rotor, can still crack, reduced rotor surface area may reduce braking performance

OEM S2000 rotor vs slotted rotor, 2pc:
~2lbs weight savings, increased pad wear, increased cost over stock rotor or stock replacement rotor, can still crack, reduced rotor surface area may reduce braking performance, rotors will probably cost $700

OEM s2000 rotor vs blank 2 pc:
~2lbs weight savings, minimal brake pad life increase, minimal braking performance increase, rotors will probably cost $700

I'm not sure what your skill level is, but unless you are in competition, increasing performance with rotors is really a lost cause.

Enkei RPF1s are like 4-6lbs lighter than stock wheels per corner and they cost like $250/wheel. At that price, that's a fairly substantial weight savings that will last until the wheel is cracked or bent. The only problem is you would have to potentially alter/modify fenders to fit the wheels.

deepbluejh

SOS makes a directionally vaned sport rotor that is 1lb lighter than stock and that cool a bit more efficiently. They are about $145 each (or about $100 more than plain blanks). You can also buy multi-piece rotors which might save you 2-3lbs, but at a cost of $600+ per set. That is VERY expensive weight savings and almost none of the racers run them The reason is because ALL rotors crack on this car under heavy abuse. Cheap, expensive, light, heavy, blank, slotted, drilled, it doesn't matter. They ALL crack during aggressive track use.

So basically the only people who might even want to spend the big bucks on the lightweight disks are cracking their rotors at such a high rate, they would rather buy cheap blanks at $40 each instead of $400 rings for their fancy two-piece rotors.

If you want to save rotational weight, a set of lightweight wheels is generally considered a much better buy than lightweight rotors. Not only will these last the life of the car, the weight is also much farther away from the center of axial rotation - which means it will have a far greater effect on the rotational polar moment of inertia than a set of hilariously expensive two-piece rotors ever will.


TLDR: Don't bother. Save your money on better mods.