C63fan

I just got the picture of new p30/31 rotor.
Does anyone know the advantage anf disadvantage of the new design comparing with old p30 two piece rotor?
It seems no weight reducing(13.7kg/30.2 lb) v.s. old p30 rotor.
Does anyone know the price for it in US? As far as I know, the old p30 rotor is USD 1000/ piece.

Thanks for help in advance!

Palladin

Had this discussion a couple months ago and the general concensus was that they are cheaper for Benz to build but not neccessarily any better than the old style. This is just a guess, not sure if anybody really knows, but it is a little strange that virtually all high-end supercars run two-piece rotors. Only other car I have seen with the new style one-piece rotors is the Audi R8.

TexasEngineer

The new P30/P31 rotors are not one piece rotors as stated above. They are “dual cast” two piece Brembo rotors like the ones found on the current generation CTS-V. More information can be found in the link.

http://www.brembo.com/US/Cars/Dual-Cast/

Palladin

Great info dude, thanks. Always nice to get the facts instead of dummies like me just guessing about it. Looks can be deceiving, I always thought they were just fancy looking one-piece rotors. Brembo probably makes the ones for the Audi R8 too.

TexasEngineer

I am happy that I could help.

Personally, if I were going to upgrade rotors I would go with the Evosport two piece rotors. They are lighter than either of the OEM two piece rotors. Also, they appear to be manufactured by the same people who built my two piece UUC rotors for my previous generation CTS-V. Here is a link for reference to the rotors I had on the V. They are strikingly similar to the rotors Evosport offers.

http://www.uucmotorwerks.com/CTS-V_f...ors/index.html

The funny thing is that while both my previous V rotors and the C63 rotors are nearly the exact same size, I only paid about $800 for the V/UUC front rotor set.

C63fan

Thanks a lot and learn a lot, too!

But if I have any further questions, where/who I can ask help from? For example, I don't quite understand how the new design can achieve the same level of "floating effect" of old two-piece-rotor? Is the cast iron "harder" than aluminium so the deformation of aluminium becomes the buffer?

dodger63

Evosports are the way to go

TexasEngineer

Floating rotors are designed to allow the rotor to expand radially outward as the rotor heats up. If you look at the cross section CAD drawing on the Brembo link as the rotor heats up and expands, it will move away from the hat in the center. At the joint where the rotor and the hat are connected, the hat is actually cast around the inward pointing stubs of the rotor. This joint will act as a slip joint allowing the stubs to move inward and outward while maintaining contact on the sides of the stub for heat transfer.

callmiro

Hey Dodger....how the hell did you get the priviledge of being on "Probation"

Wear your badge with honour bro!

dodger63

I'm trying I think I only have 5 days left... But thanks.. I used an improper word on the forum but I did the trick were I put ! In between the sh and the rest of that word so..

callmiro

Fu<k...That's all it took???....i hope i never make that mistake

dodger63

That sums it up!! Let me no how you fare

GHAZAN

I wonder if UUC can manufacture rotors for us...since evosport has a 3 month backorder

C63fan

Thanks again!

Several issues need to be clarified here.
1. Since the hat is actually "cast around" the inward pointing stubs of the rotor, the connecting surfaces of both part are stuck/bound together tightly, right!
2. When the the rotor heats up and expands, the inward stubs should expand toward to center of hat. Am I right? PLS see the attached PDF file.
3. Since aluminum is softer than cast iron, the deformation on the hat will be more as the floating effect provider. Am I correct?

Add another picture for closer look of this new design.

TexasEngineer

1. No. The friction may be high (the are “tight”), but they are not bonded/fused together (this requires a lengthy metallurgy explanation, and I don’t have time, sorry). The casting can be designed to have specific tolerances, and I am sure that there are. Sacrificial pieces can be included in the casting to maintain gaps where needed.
2. The inward stubs would expand toward the middle, but the rotor, a ring, would expand at a higher rate(it is larger, so it will have more thermal expansion). When a ring under goes thermal expansion, both the inner and outer radii increase. The net affect will be that the stubs will move away from the hat, because the inner radius expands at a greater rate than the stubs. I could not get the file to open for some reason.
3. Yes the deformation of the hat should provide some floating effect.

I would like to make a note that I am note claiming that these work better than a standard two piece floating rotor. I am claiming that they work similarly.

Palladin

Very interesting from a technical point of view, but I have to say that I still like the looks and proven performance of the old two-piece floating rotors (EvoSport style) that are still used on most ultra-high-performance cars. And since the new design doesn't really reduce the weight I am going to stick to my theory that the new design is mainly being evolved because it's easier to manufacture. Looks like it can all be done by machine without having to manually fasten the hats to the rotors, hence saving the annual salary of some italian guy at Brembo who has been there for 25 years and makes too much money.

badu

On UUC's website, they have quite a few products developed for EvoSport for M3 application. Therefore, i won't be surprised if EvoSport C63 rotors were also developed by UUC.

Does someone want to talk to UUC about this?

GHAZAN

yea someone call UUC for me....maybe harrower will do it

brad @ evosport

STOP!

Nothing EVER was developed by UUC for evosport.

UUC copied many of our designs for many products! So much so, one owner even tracked down and visited one of our manufacturing facilities once and asked for them to just make our products with their name (many years ago). This has been WELL discussed on many BMW boards and email lists by the way.

UUC products are not sold or even installed in our shop (even if you bring it in). Too many issues and problems and UUC ownership ALWAYS blames the install. lol

This is very serious what you wrote, please get the facts straight on this. I could not be insulted more!

thanks
brad

GHAZAN

well i guess someone other than myself can still call them and see if they can make a rotor for 63s....more options = better value for us

SMP

The best price is not always the best deal. Especially when it comes to brakes. Having all that power is sure nice, but having brakes you can trust and rely on, is more important. I for one, wouldn't want to find out what it feels like to be a passenger because of brake failure.

I would never compromise on brakes, wheels or tires to safe a few dollars.

TexasEngineer

Just curious, who actually manufactures these rotors? Who designs them? I am not talking about taking measurement to spec out the hat and rotor size. I am talking about who actually did the engineering and designing for these rotors. What exactly did UUC copy? When you say “our manufacturing facilities” do you own the facility? Are they a partner or a subsidiary?

Just to be clear, I am in no way advocating for UUC. Also, I believe the rotors offered by Evosport are the best available for the C63. I also believe they are the same exact rotors I had on my CTS-V. I just want to know where they really come from.

TexasEngineer

I completely agree that the best price is not always the best deal, but I know for a fact that the UUC rotors are of very high quality. The fact that the Evosport rotors appears to be the same as the UUC rotors leads me to believe they are also of very high quality.

brad @ evosport

I am clearly not going to detail the subcontractors that we use to do bits and pieces of our work.

Like most all businesses, we outsource much of our work. We have a full fabrication facility in house, however, for production items, they are sourced out to production houses. One such house is where UUC arrived and asked the owner to take our BMW pulleys and put their name and sell them to him.

As far as the rotors, we do the process in house along with our manufacturer. We examine the vehicle and the available disc options. This is limited by fitment with stock calipers. We then select and machine the rotors and hats and assemble with the highest quality fasteners.

The raw discs that others use, including UUC, may be from the same maker, however, the complete product is not, that I know for certain.

thanks
brad

GHAZAN

^ you should be a politician or on DWTS...thats the best 1-2 sidestep