Trying to put together a list of suspension and brake improvements on the GTS. Please contribute if you find out more.
Front Suspension
Rear Suspension- Dual-adjustable (compression and rebound, individually) dampers
- Height-adjustable spring collars (set at -12mm/0.47" vs. M3)
- Linear race springs (800lb/in)
- Solid sub-frame mounts
Front Brakes by Brembo- 6-piston fixed caliper
- 378 x 32, vented and perforated
- Steel-braided brake lines
Rear Brakes by Brembo- 4-piston fixed caliper
- 380 x 28, vented and perforated
- Steel-braided brake lines