APR Valve Spring System - 5.0TFSI / 5.2 FSI

It's not uncommon to experience valve float with the OEM valve springs, even below the OEM rev limit. On some applications like the 2.0 TSI, backpressure from the K04 turbocharger has been known to force the exhaust valves open. This has been noticed on vehicles with overly weak OEM valve springs and some with higher miles that have simply lost their stiffness over time.

This issue accompanies misfires commonly above 5000 RPM. In some extreme cases, valves are forced open and the vehicle ceases accelerating any further. A quick datalog of intake mass airflow and boost pressure at wide open throttle will show a sudden rise in boost pressure with an immediate loss of airflow as pressure from the open valves is pushed back into the intake manifold.

On other applications, valve float can begin to occur just beyond the OEM rev limit. While other components, such as higher strength valves are often required for extremely high revving applications, the APR Valve Spring System will eliminate float well beyond the revving constraints set forth by the other components.

APR is pleased to present the APR Valve Spring System.

The APR Valve Spring System is a high performance, lightweight upgrade designed to increase valve control and eradicate valve float common on many applications. APR's design specifications called for a valve spring, retainer and spring seat combination that doesn't overpower and snap the OEM valves or erode the aluminum spring seat, while still maintaining exceptional valve control. The result is an advanced design that's 28% lighter yet 20% stiffer than the high performance OEM Golf R setup and is proven to eliminate the OEM valve train's weakest link. We call it Performance Without Compromise!

• Increase valve train control
• 71% weight reduction over OEM Golf R retainers
• 19% weight reduction over OEM Golf R springs
• 20% stiffness increase over OEM Golf R springs
• Eradicates TSI K04 "ÌÎå«Ì´åvalve float"ÌÎå«Ì´å issues
• Supports higher revving applications
• Weight saving beehive spring design
• ASTM A877A OTSC round wire steel springs
• 6AL4V American titanium retainers
• 4140 heat-treated chrome molly steel spring seats with black oxide coating
• 29 grams per spring
• 2 grams per retainer
• Compatible with OEM valves
• Spring seats included to protects against aluminum erosion in the head

Vehicle Fitment
Audi/S8
Audi/S6 (C5)
Audi/RS6 (C6)
Audi/R8 Mk1 (42 06-15)