Has anyone tried MS3 Calipers/Rotors on an 8?
 

I've have been kicking this idea around in my head for a while. Has anyone looked at swapping MS3 brakes onto an 8? I have not looked into this fully, but I would not be surprised if the mounting brackets bolted right up (I know it works this way on the regular 3). IIRC the rotors are .1 inch smaller, but the calipers are much bigger. This would provide a more aggressive look. I would not expect there to be any performance increase, at least none that would be noticeable on the street. The MS3 front brakes are HUGE when compared to the RX8 side by side. Another difference is that the MS3 guys are able to run many 16 inch wheels, so for those looking to run a smaller wheel for the weight reduction, reduced cost of rubber, or gearing advantage, this might be another bonus.

I know that I will never get into a situation where the stock brakes are not good enough as long as I keep decent pads on the car, but the backyard mechanic in me keeps me interested in this idea.

RX8
- Front - 12.7-inch vented disc
- Rear - 11.9-inch vented disc

Speed3
- Front - 12.6-inch vented disk
- Rear - 11-inch vented disk

From just the raw numbers it looks like a bad idea, but look at them side by side and you will see what I am getting at.

I wish I could find a picture of the pads or calipers side by side. Has anyone else researched this? Any thoughts?

Flame away if you must.

thought I had seen/heard it all before :lol:

No.

Have you ever driven the braking system to its limits? If so i'm sure you can find a better pad and raise that limit.
The stopping power per se is probably pretty similar, what it's not similar is the brake bias needed in the 2 different cars.
The system you're describing is designed around a fwd, nose-heavy car. The systems have to be different otherwise they'd be using the same components from the factory just for cutting costs.
Also don't be fooled by the calipers' dimensions, they mean close to nothing. Piston number also doesn't count much if the whole system is designed properly.
It is alright to experiment but playing with stopping power in an empirical way is not wise.
What if you increase the front stopping power too much and make the rear too light when turning? you may be stopping a whole whopping foot earlier but at what cost :)

Nah... and what about BBKs ?
They are bigger and I assume they brake better than MS3 brakes.
Damn... even replacing the OEM pads or rotors for better ones could cause You to loose the rear.

I would also be interested in replacing them, calipers mostly.

In my country we also have braking systems called AP Ryking that guys for example put on an Evo. They are about 1/3 of a price of AP Racing and are made from a rotor from Cayene or Touareg and a Porshe calipper + some pads.
I don't have a link now but I can search for one if You wish.

Replacing the OEM brakes is pretty common, usually for better braking, not worse :P

I guess I will just call my local dealer and ask them.
Or maybe brakes from the Speed 6 ?

Solidtrance, could You call Your local dealer as well ?

I actually had a chance to look at MS3 and RX8 pads next to each other on Sunday night and the difference was the huge difference that I though. I would guess that the MS3 pads were 10-15% larger. The MS3 pads are also 15-20% thicker.

After posting this i spent a little time doing actual research and the more I look into it the more it looks difficult.

bse50, thanks for the info. I am currently on a set of Axxis ULT's and I love them. I'm know there are more aggressive pads out there, but I am happy with the ULT's. I have never felt anything from the brakes that would indicate that they were near their limit. I don't think I am capable of reaching the limits of the breaks on my 8. I don't think most people who go with a "big break" kit have maxed out the breaks on their cars, with the exception of the few who track or autox very seriously. Most of the time a big break kit is about looks.

Already made the call, Ordered a rotor from both cars to see how different they are. I doubt there will be an easy way to use the MS3 rotor on the 8 so I need to see how thick the MS3 rotor is. I found a few MS3 Calipers that are available at a local pick-n-pull that are cheap enough that I wouldn't mind picking one up just to use for a mock up. There are some significant differences that need to be addressed. I am just curious at this point and want to find out if it is possible and how much work it would take. I would say that there is little to no chance that I would do this to my car, just trying to answer a question that I have.

That's a lot of assuming that tends to be false. When you put bigger brakes on a car you are adding weight and potentially increasing the total stopping distance as well as disrupting the brake bias.

A lot of people replace their OEM brakes. Many of them do get worse braking from cheap poorly designed systems.

Next thread: Anyone convert their RX-8 to FWD yet?!?

What exacly tends to be false ?:O
You seriously think that AP Racing Big Brake weights so much more that it's stopping power is worse than the OEM brake ? lol... ?

So what would be the point of replacing the OEM brakes on sports cars if the OEM brakes are better (just cuz they weight less) ... ?

Never saw anyone who has a BBK to increase their braking distace comparing to the OEM set.

Solidtrance how aboout Speed 6 or CX-7 / CX-9 brakes on the RX-8 ?

Really. And you think that just because it says AP Racing on the side that it's better? My point is, like all aftermarket performance parts, there's a lot of crap out there and you need to look for real data provided by the manufacturers of the kit to see if it's actually any better.

Exactly how much would your stopping distance decrease with stock rims and tires if you put on the AP racing big brake kit?

I already know the answer BTW.

Ok this shit has got to stop. I've tried to ignore this, I want to be nice, it is the holiday season and all. Maybe the OP is just trying to get the goat of reasonable people, IDK. Stop posting this nonsense and read the Brake FAQ https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/brake-faq-167264/ for a starter. Then go to the Stop Tech site and read all their White Papers in the Technical Information section beginning with the one on Brake Bias http://stoptech.com/tech_info/tech_white_papers.shtml .

Key words you should be on the lookout for are hydraulic, bias, piston diameter, load shift (aka weight transfer), balance.

Then without any further input from me or any of the other people with half a clue, ask yourself why this whole post is a futile excercise in public embarrassment and promise yourself you won't open your mouth without thinking things through more carefully in the future. Please.

^100% - The caliber (no not caliper) of some comments evidenced in this thread is almost totally based on no reasoning at all... :icon_no2: quite an achievement!

..so much "want to look at the difference between this and that" ... like looking at rotors or calipers or pads can tell you anything whatsoever about braking efficiency, ability, or stopping distances...or a braking component's suitability for purpose, for that matter!

Don't some of you realize brakes are "engineered systems"? ...meaning they are "designed to a performance level", not "drawn up in a paint program to look like they'd work"? Metallurgy, pad composition and materials design, in combination with fluid dynamics, design metrics/empirical chassis evaluation are just some of the things that make any car's brakes "good".... not what they 'look like' FCOL!

Some of the comments in this thread FAIL so bad as to be an embarrassment to the whole of performance car-dom. If you think the basics of RX-8 brakes need improvement so much (except for cosmetics)... I'd suggest you 1st need to graduate from an automobile engineering school (or race school driving an RX-8) before embarrassing yourselves further.

I really hope I'm the last person to post here - ever.

I did....

Someone yelled "V-Tech Yo" at me so I switched it back.

Wow, didn't think this would cause so much drama. Jim, I have read many of your posts on this subject already and found them to be really helpful, so I certainly was not trying to piss you or anyone off. Thanks for the link to Stoptech's info. i will read them as soon as I have a little free time.

Everyone relax. I will not pursue this here any longer if it is that offensive. I don't understand why this is so offensive to some? Maybe because the MS3 is a "cheaper" car, or FWD? I wonder how many of you read the whole OP.

to each his own but seriously i don't think there is any benefits to what your doing, your time and money would have been better spent on a set of 2peice rotors and aggressive pads, and a can of caliper paint.

Your not only potentialy upsetting your brake balance by decreasing your rotor radius and changing to ms3 calipers, you're also upping your caliper weight, decreasing brake torque, and your rotors ability to dissipate heat.

The rotor radius is smaller but the surface area of the pad is larger. That is one of the reasons I started thinking about this. After the initial response here, a bit more negative than I expected, I have not taken the time to explain my thinking and what I am actually doing to pursue this. No one seems to care, which is fine. If the thread title referenced swapping brakes off of a Porsche would the response have been the same?

I have a lot of research to do and a lot to learn before I even consider messing with something as important as the break system. This thread was intended to be a part of that process.

from brembo's FAQ

What is brake torque?
Brake torque is essentially the power of the braking system. The brake caliper acts on the disc at a certain distance from the hub center, known as the effective radius. The force exerted by the caliper, multiplied by the effective radius of the system equals the brake torque. Increasing either the force applied by the caliper, or the effective radius results in increased brake torque.

Why use larger discs?
Braking generates heat, and the more heat the disc can absorb and dissipate, the greater the fade resistance of the system. Additionally, the use of a larger disc generally results in a larger effective radius, which increases brake torque.

Is the biggest brake disc the best answer for my vehicle?
Not necessarily. There are many factors to take into account when choosing a performance brake system. First and foremost, a brake system must be designed based on the vehicle parameters, and the type of use it will experience. Brake systems are designed to operate best within a prescribed temperature range. While modern high performance friction materials broaden this temperature range from relatively cold pad temperatures to the high temperatures experienced in performance driving situations, the use of a disc that is too large will limit disc temperatures to the extreme lower end of this range. Not only will the disc temperature not reach the optimum range, but it will also be heavier than necessary. Below you will find an explanation of how reducing the weight of the braking system further enhances performance.

Any place where I wrote that ? I brought up AP Racing just an example.

Sure, thats what we have forums for. To discuss.
Or not... ?

Enlight me please.
Anyone is using the stock tires when it comes to performance ... ?