Since about the middle of last summer, I started to notice that at least one of my calipers would seize just a little after being on the brakes for a while. The older 911 calipers were fairly known for this and the logical choice would've been to just replace it with a new OEM caliper or rebuild them. That's not really how I do things especially when there is an opportunity for an appropriate upgrade.
Rear brakes converted to Boxster calipers
In this case, I stumbled upon the Elephant Racing Boxster caliper conversion kit. I was initially just going to order the full kit from Elephant Racing including the caliper, rotors and pads but after consulting with Speedsport Tuning, I had them order just the adapter kit and piece the rest separately so we could better tailor the kit to my needs.
Front brakes converted to Boxster calipers
The kit consists of billet aluminum adapter brackets to adapt the Boxster's axial mounted calipers to the radial mounts of the older air cooled 911s as well as mounting hardware and braided stainless brake lines. These are design to take the base Boxster calipers from 1997-2004. I had them get me new slotted Sebro rotors (from the 3.2 Carrera - 84-89 911) and OEM Textar pads. I could've gone with a more aggressive brake pad compound but it's important to match the pads to the tires, especially on a non-ABS equipped car. Since I run the car on regular Continental DW tires, having an overly aggressive pad would likely be too much and make it easier to lock up the tires under heavy braking.
Clearancing required
There's a little bit of clearancing required to make the brackets work but nothing too crazy. The shop said the hard lines supplied with the kit don't fit really well. They're just a tad too short for comfort so they fabricated correct length lines for me.
New stainless brake lines
New stainless brake lines
Of course, changing out all the brakes like this requires a complete brake bleed. We used standard SL6 DOT4 ATE brake fluid.
Brakes being bled
One of the main reasons I chose to upgrade to modern style calipers is that they are monoblock aluminum, which makes them both lighter and stronger. I could've gone and found some used Boxster calipers to save some money but I had the shop order brand new calipers from Porsche since I felt they were reasonably priced for new OEM calipers anyway. After all the money invested in this vehicle, seems to make little sense skimping out on the most important part of the car...the thing that makes it stop.
Discerning eyes will spot the non-stock calipers behind the Fuchs
Very appropriate OEM+ upgrade
Snarky purists will comment that this isn't really an upgrade and I'd have to agree that yes, from a pure brake performance perspective, the old OEM calipers offer basically the same stopping power (provided they don't bind up). What I do get with this restomod using more modern parts is the improved reliability, decreased weight, and more predictable brake modulation. When it comes to stopping power, having confidence it'll work the same way every time is the most important thing to me.
Looking sweet with her summer setup back on - 3-13-2022
My 83SC has a brake booster and from what I could tell on my long drive home, the pedal feel and balance was still very good. Modulation was easy and it didn't change how the car felt under braking dramatically, which for me, is a good thing. I think if you have a non-brake boosted car, you'd likely have to consider switching to the master cylinder from a 930 turbo to be able to control the larger pistons used in these calipers. I will say that I'm very satisfied with this setup and would highly recommend it for anyone looking to put a more modern brake system into their old air cooled car.
Maintenance Update:
Mileage: 169,654
- 97-04 Base Boxster Calipers
- Sebro slotted front rotors - 91135104123SET
- Sebro slotted rear rotors - 285802CSET
- Textar OEM brake pads
- Elephant Racing Boxster a caliper adapter kit
- Stainless brake lines
- Brake flush and bleed with ATE SL6 DOT4 low viscosity fluid
