Here at MRN a cost effective BBK (Big Brake Kit) has been something that has been on the to do list for some time but with the first development car having PCCB it was not all that easy to develop. Luckily the new 987.2 development car has "normal" brakes so a new BBK is going to be available very soon!
This BBK will allow the fitment of 350mm discs from another Porsche model to the front of the following models:
911 996 Carrera 2 and Carrera 4. (Not C4S, Turbo or GT3).
911 997.1 Carrera 2 and Carrera 4. (Not S models, Turbo or GT3)
986 Boxster
987 Boxster and Cayman
This BBK will space out the front wheels by 8mm (per side), a VERY common modification is 7mm front wheel spacers and if you are already running these you won't even need new wheel bolts to fit this kit!
The kit involves fitting a very neat spacer between the hub and the new 350mm disc(s), there were a few challenges to overcome in designing this part as all of the components need to be concentrically located to ensure they run true and balanced when fitted. The biggest issue was reinstating the wheel location spigot as that would decrease from 12.5mm down to a mere 4.5mm and that is not a number we are comfortable with to locate such an important load bearing item. You will be able to see from the pictures below how we got around this issue. The spacer will be secured to the hub in the same way the OEM disc is secured by using 2x countersunk screws, the 350mm disc will then be secured to the spacer the exact same way so all fixings as per the OEM method.
The kit will not typically come supplied with the discs and wheel bolts as the customer will likely have specific colour bolts and locking bolt preferences but everything else you need will be in the kit including spacers for the calipers and spacers for the solid brake line where it is anchored to the upright and all the longer fasteners to suit.
*Pictured above is a 3D printed spacer, the kit part will be CNC machined and anodised aluminium*
Below are "before and after" pictures on an S model, the 350mm disc not only performs far better but also looks so much better, on 19" (or larger) wheels it will look better still!
Standard S model discs
350mm BBK
The 987.2 development car with the kit fitted above has 18" OEM wheels and as you can see there are no clearance issues at all.
The cost of the kit is expected to be around £300, at the time of posting this blog, discs are from £90 each and wheel bolts from £30 for a front set. So all in you could be paying as little as £510 for the entire conversion!*
Below is a short animation of the kit parts
Check the MRN shop for current price and availability of the kit!
*it is recommended to replace brake pads at the same time as fitting new discs