Ferrea Complete Single/Dual Valve Spring Kit

The Ferrea Complete Single/Dual Valve Spring Kit (KT4040) is engineered to enhance the performance and reliability of VW and Audi 1.8T 20V engines, particularly in high-revving and racing applications. These valve springs are crafted from premium-grade alloys and undergo special thermal treatment, ensuring uniform load and stress distribution even under extreme conditions. This advanced design helps prevent common stock valvetrain issues such as binding, breaking, and valve float, allowing for more aggressive camshaft profiles and higher RPM limits without compromising engine integrity. The kit includes 12 single springs (S10055) with titanium retainers (E11031) and seat locators (SL1025), as well as 8 dual springs (S10056) with titanium retainers (E11032) and seat locators (SL1026). Ferrea's springs are heat-treated and stress-relieved to maximize lifespan and provide the stability necessary for high-lift, high-RPM valvetrains. The accompanying retainers are CNC-machined from various materials, including titanium, offering superior strength and stability. The spring seat locators are CNC machined from 4140 chromoly alloy with a hard Nitrided surface for enhanced toughness and wear resistance. This valve spring kit is compatible with a range of VW and Audi models equipped with the 1.8T 20V engine, including the Audi A4 B5 (1996-2001), A4 B6 (2002-2005), TT Mk1 (1998-2007), VW Golf/GTI Mk4 (1999.5-2005), Mk4 (1999.5-2005), and New Beetle (1998-2010), as well as Passat B5 (1998-2005) models. Specific fitments include FWD, Quattro, and 4Motion variants, as well as particular submodels like the 337/20th edition GTI and GLI.