20% discount reached! Also on this GB is a BBK with e9x M3 sized rotors.
GB for RacingBrake 2 piece rotors for ZCP/Z4M. Also available will be a progressive upgrade for the ZCP rotors, am RB aluminum 4 piston caliper with 40mm/44mm pistons (same as common Brembo and Stoptech piston sizes
for E46 M3 BBK). RB calipers have been measured to give 5-6mm more wheel clearance than the comparable StopTech or Brembo BBK kits.
As another option if you want the caliper upgrade, you can chose to go with E9X M3 sized front and rear rotors with caliper upgrades as well.
For those that chose to stay ZCP sized, at any time later, they may chose to upgrade to E9X M3 sized rotors just by purchasing new brackets for the calipers and new rotor rings. The calipers and the hats are the same!
RB has also offered all participants all of the above options at the same level discount as the GB for future purchases!
Please see the link below for further info.
GROUPBUY LINK at RacingBrake
Good news for those interested in ZCP/Z4M 2 piece rotors!
For ALL participants RB will thrown in a free wheel stud/nut conversion kit:
LINK
This is a 100 dollar freebie for ALL PARTICIPANTS in the ZCP/Z4M rotor GB! For those that want to purchase an additional wheel stud kit, RB will offer a 10% discount on the second set.
From RB site:
"RB wheel studs are made of alloy steel, heat treated, and certified to SAE 10.9 class. They feature an 8mm hex head for easy installation and replacement.
RB wheel nuts are made of alloy steel, with chrome plating for an attractive and lasting finish.
Length: 80mm (3.15") After installation."
Rotors can be found here:
Link to 2 piece rotors
Note that rotors are 30mm in thickness as compared to OE which are 28mm. OE rotors have min wear at 1.6mm however RB rotors will go 2mm, which is typical for most BBK 2 piece rotors. Combined with the extra hardness of the steel used and the much better cooling, these should last significantly longer than OE. User "TheHACK" on Zpost actually runs these exact rotors that are in this GB. In 2010 he posted that he had had the rotors on the car for 4 years and 4000 miles of track duty and they still had life left. NO WAY an OE rotor would take that abuse!
SEE POST
See the below reviews for extensive photos.
The discount is as follows:
15% for 5 or more orders (discounted price: $756.41)
20% for 10 or more orders (discounted price: $711.91)
If we can get enough people this could be a really great deal!
The above prices include RB ET300 brake pads. I've asked if they will offer the discs without pads or with different more aggressive compounds, I'll update when I recieve an answer.
RB will take $30 off the price if no pads are desired and will charge approximately $40 if you want to upgrade pads to a more aggressive compound...see GB link above.
*UPDATE 09-25-12: RB has included a Progressive caliper upgrade as well, comparible to Stoptech and Brembo at a lower price with (arguably) nicer components. Rear two piece rotors will also be made available. For any participants of this groupbuy, RB has stated that they will offer the same discount on the PU upgrade or rear two piece rotors regardless of how many previous participants chose to purchase.
See these review for the RacingBrake rotor review for 335i and 135i rotors, both of which use the same technology as the rotors here.
Cliffnotes from linked reviews below if you don't want to click (though I recommend you do!)
-The OEM rotor is about 145 on the Brinell hardness scale and the Stoptech rotor is around 171.
The RacingBrake rotors that Mr.5 (OP of 335i review) tested were 196 and 193.
-Better cooling than OE rotors due to center mount rotor configuration (that no other rotors use) and convergent vanes. (Though there is not alot of conclusive date to back this up, it's enough for me that the Mr.5 noticed a 30 degree rotor temp difference in favor of RB rotors.
-E90 325i owner fitted with 135i brakes had reviously noticed fade on the track. After switching to RB rotors fade was gone and OP of review decreased 2 seconds off of lap time by being able to brake later towards end of session.
The 335i review shows a rotor temp difference of around 30 degrees under the same conditions (stock on one side, RB on the other).
SEE REVIEW
The 135i review states that OP had issues with fluid boiling and pedal getting soft. RB rotors maintained a nice pedal feel and the OP shaved 2 seconds off his previous time.
SEE REVIEW
*UPDATE: For those interested in the rear rotors, RB informed me that they will be producing both the 2 piece rear rotor with aluminum hat and steel liner for Ebrake function as well as a PU upgrade. They will ship the 2 pc front rotors, then PU upgrade for front, then 2 pc rear rotors and then PU rear. All participants can upgrade/add any of these options for a limited time...as of now the front PU can be purchased at GB discount up to 6 months after front rotors are shipped. Rears will most likely be similar.
The group buy closes 10/15/12.