The 986 generation Boxster S uses a sweet set of four piston Brembos, meanwhile TTs are stuck with single piston VAG parts bin calipers. How lame is that?
Fortunately, Boxster front brakes swap very easily onto our cars. They use the same rotors, and you can keep the same brake lines. You can get a set of Boxster calipers on eBay for ~$400 or so. If their paint is in lousy condition, send them my way! I'll powdercoat them in the color of your choice.
Here's l88m22vette's thread on how he did his upgrade:
Here's his parts list:
* Mk1 Porsche Boxster (986) front calipers - $415
-- Porsche parts numbers 986.351.421, 986.351.422
-- Brembo 1pc 4-piston aluminum calipers, as opposed to the stock steel 2pc 2-piston calipers. I got them from German Auto Parts Distributors, an awesome source - 706-865-5200. Ask for Joe. I received the calipers in great condition.
* 986 replacement hardlines and bleeder valves - $180. Pelicanparts.com
* Pure Motorsports 986 carriers (with carrier to caliper bolts) - $175
* Hawk HPS pads (or whichever you like)
--- Boxster front pad #: HB289F.610 - $95
--- Audi 225TT rear pad #: HB364F.587 - $50
* SS front/rear brake lines (with spring clips) - $150, ECS
* Boxster caliper-specific banjo bolts (different thread pitch than VAG) - $25, ECS
* New plain, vented replacement rotors for 225 - $160, MJM Autohaus
* Brake fluid - Motul RBF600, $45...I was going to use ATE Superblue, but that will eat up seals.