[335fourdoor]

does this co need any beta users? i'd be interested.

[Mr. 5]

Originally Posted by 335fourdoor

does this co need any beta users? i'd be interested.

I think they have that covered for now but will keep you in mind if they need more.

[BrianMN]

If the price is right on these rotors, I will surely buy!

Reducing rotating mass is always a win!

[Mr. 5]

Originally Posted by BrianMN

If the price is right on these rotors, I will surely buy!

Reducing rotating mass is always a win!

I believe that the price is going to be in the 350 range, but not 100% sure.

[DJKhan85]

Did they give a time estimate on these?

[Mr. 5]

Originally Posted by DJKhan85

Did they give a time estimate on these?

They said about 10-14 weeks and the clock started ticking about 2 weeks ago.

[The HACK]

Typical product development cycle. 3 months is usually the standard answer I get from our engineering department. When I got my brakes, it didn't take long for RacingBrake to have a prototype done...Actually maybe a couple of weeks. But from that point on, it was fit, adjust, re-fit, rinse and repeat until they were absolutely satisfied that it wouldn't interfere with any hardware. I was actually ready and satisfied by the 2nd iteration but didn't get a final finished product until about 3 months later. Seems their developer is rather "meticulous" when it came to fitting it on my MZ4 Coupe. Part of the difficulty was, although the MZ4 Coupe shares parts with the M3, it had its own "charms" and that if they can get their rotor hats to fit and balance on the MZ4 Coupe right, the same rotor hat would work for ALL M3s.

Figure on applications specific to the 335i to go a little easier and smoother. But the same test fit, adjust, re-fit procedure is what's going to take a lot of time.

[marconi118]

yesterday saw a Z4 3.0IS and it has 2 pieces Aluminium + Steel rotors
The callipers are the same as the 335i

Have a look at your dealer if they can order these OEM rotors !!!!



PS: the Z4 3.0 IS has the same airbox as the standard 335i, no upgraded one as the DINAN or Alpina

[The HACK]

Originally Posted by marconi118

yesterday saw a Z4 3.0IS and it has 2 pieces Aluminium + Steel rotors
The callipers are the same as the 335i

Have a look at your dealer if they can order these OEM rotors !!!!



PS: the Z4 3.0 IS has the same airbox as the standard 335i, no upgraded one as the DINAN or Alpina

While the OEM 2 piece rotor offers all the tangible benefits of true floating rotors (the MZ4 rotors are true two piece, center mounted floating rotors) in terms of performance, the fastening hardware is cast into the hub and therefore you can not replace the ring only. You must replace the ring and hub at the same time despite the 2 piece design.

Meaning every time I need to swap out my rotors I must pay $300 per rotor since these OEM 2 piece rotors are very difficult to make. There's an exploded view of the OEM center mount 2 piece diagram out on the intarweb somewhere and it is truly fascinating how BMW put these rotors together. Awesome stuff.

[stressdoc]

I will gladly put out $300 per OEM 2-piece rotor -- better than $450 for the DBA ones. Anyone know what the weights are?
Are these the parts you are thinking are interchangeable?

335 01 Brake disc, ventilated 348X30 2 34116770729 $173.91

MZ4 01 Brake disc, ventilated, right 345X28 1 34112282446 $274.42

[marconi118]

I am not talking about the M Z4 but about the new Z4 3.0IS (same engine as 335IS) rotors have exactly the same dimension as the 335i but in 2 piece construction.

[DJKhan85]

He's right. I just checked on realoem.com

z4 35is - 34116773201 -CALIPER HOUSING LEFT
335 - 34116773201 - CALIPER HOUSING LEFT

z4 35is -34116782593 - 348X30 - rotors. No price though.
335 - 34116770729 - 348X30 - Rotors

[tlrid3r]

does any one know if the caliper from the e92 m3 is the same as the e92 335i. it looks the same. I tried to find the info but not success yet. If so I was think what can be done is to use the caliper bracket from M3 and the two piece rotor on the 335i for a OEM big brake kit. kind like the e46 to e46 competition package its upgradeable

[Imperator]

Originally Posted by DJKhan85

He's right. I just checked on realoem.com

z4 35is - 34116773201 -CALIPER HOUSING LEFT
335 - 34116773201 - CALIPER HOUSING LEFT

z4 35is -34116782593 - 348X30 - rotors. No price though.
335 - 34116770729 - 348X30 - Rotors

Tischer lists that Z4 SD 35is rotor at $169.06/ea.

[stressdoc]

Wow, the front ones from the z4 35is should work! I would love to know the weights.

Any 2-piece rotors available for the rear? 336 x 22

BMW used to equip some of the high performance models in Europe with 2 piece floating rotors, which you could special order the parts to get them here. Exact replacements, just 2-piece floating rotors instead of the doggy solid crap they put on USA models.

[JoeyFiasco]

Originally Posted by Imperator

Tischer lists that Z4 SD 35is rotor at $169.06/ea.

that does sound like a pretty good deal. I'll wait 'til I see/get more info though

[stressdoc]

I sent Evan & Jason (aka Tischer) PMs to see if they can scramble together a brake kit for us.

[DJKhan85]

I examined one of the rotors from the z4 35is when I was last at my dealer. I don't think we can reuse the hub at all with a new disc. We would just have to re-buy the whole thing as stated by "The Hack" above.

The 2 piece rotors in development would be around 350 a piece for the initial buy but how much for a replacement "rotor ring"?

[stressdoc]

At $169 per, I am more than happy to replace the whole rotor. Replacement rings can easily run as much or more. Now I just want to find some for the rear.

[stressdoc]

KO has a different sized rotor listed for z4 35is. I wonder if the 338 size is a euro thing? Or just a typo by KO.

Part #: 34116782601-9
KO Price: $136.72
Shipping: Weight Fee May Apply (Approx: $15.20) & *Ship Group
Stock Status: In Stock - Ready to Ship!


Sorry. No picture is available for this part.
------------------------------------------------------------------------------------------
Book #: 34 11 6 782 601
Description: Brake Disc Front 330 X 24 mm
Applications: Z4 sDrive35i E89
Manufacturer: GENUINE BMW

[The HACK]

Just from my personal experience with swapping out the 2 piece OEM floating rotors on the MZ4 Coupe and using the RacingBrake 2 piece floating rotors, there are some subtle differences...

Obviously, the 2 piece floating rotors on the MZ4 Coupe (same as the M3 Competition package) is a lot thicker and more expensive (retails for $360, Tischer sells them for $290-ish) so if I were to replace 2 sets of front rotors with the RacingBrake 2 piece rotors then I would have made my money back, since the replacement rotor rings for the 345mmx28mm from RB runs about $120 ea.

However, there are performance advantages to RB's 2 piece rotors as well, and if this company making the 2 piece application designs their rotor to the same high standards RB does, then I can see two tangible benefits, both on performance and longevity. Now, keep in mind, this is my experience with RacingBrake rotors, whoever is making this new 2 piece application for the 335i may or may not live up to the same standards. We shall see.

First of all, I ran two separate events back to back with OEM rotors on OEM pads, and then RB rotors on OEM pads. While it was done on two separate tracks (California Speedway and Buttonwillow), both are notorious for being very VERY tough on brakes. Buttonwillow especially so since there's very little break for brakes to cool down. OEM pads faded by the 2nd full session at California Speedway, and while Buttonwillow was ran differently (it was a private event some friends and I put together so there are no defined "sessions." You drive when you want to drive) the brakes didn't start showing fade issues until much much later in the afternoon. So from a cooling perspective, without any other modifications the RB rotors seem significantly better at providing cooling to the brake system. Now, whether it's because the RB rotors are slotted vs. the drilled OEM 2 piece, or the patented convergent vanes inside the RB rotors (forces air out at accelerated rate to improve cooling), the aftermarket rotors did manage heat better than the superb BMW 2 piece system.

Another side benefit to that improved cooling capacity/efficiency, I'm now on the 4th year on these same RB rotors on the MZ4 Coupe (again, your mileage WILL vary since the 335i is about 300 lbs heavier on smaller rotors) and they still look brand new. Nary a lip on the rotor. I've gone through 2 sets of track pads now in 4 years (another side benefit, the more effective the rotors evacuate heat, the longer they and the pads last), while averaging about 15 days a year. In the past, at best, I would go through a set of pad a year, sometimes 2 depending on what I was driving.

On a side note, the rotors do show a lot more microscopic surface cracks due to the rapid heating and cooling cycle vs. the rear rotors (still OEM drilled 2 piece). I was told microscopic cracks are normal and nothing to worry about from experienced club racing buddies. At current wear rate, it looks like I will wear through 2 sets of OEM rotors for every set of RB rotors. So far in nearly 4 years of running the RB rotors, the ONLY time I've experienced fade was on a set of Cobalt XR-3 pads with about 40% meat left (typically I don't let it go past 50% but I was waiting for a set of Hawk DTC-60s to become available for a nice discount). Obviously thinner pad equals less thermal capacity and less fade resistance.

[stressdoc]

Tischer put the z4 35is rotors on as an option for their brake package, but evidently they could take a while to get from Germany.

For track use the RB (or DBA) rotors sound like the way to go, as per Hack's discussion above.

For street use the Z4 2 piece rotors seem like a viable option, and one that BMW should be happy to provide warranty for.

Anyone have a clue what the weight savings are between the BMW 2 piece and the solid rotors? 1-2 lbs.?