Add to Cart Quaife Birkin S3 Roadster Quaife Atb Helical Lsd Differential, Qdh1L $992.56 Quaife ATB Helical LSD differential for Birkin S3 Roadster is a direct replacement for the standard Birkin S3 Roadster open differential. The Quaife ATB Helical LSD differential transforms your car’s performance. Unlike a conventional plate-style... $992.56 Add to Cart