Home - Return to Previous Page
Additional Images

APR Valve Spring Kit For 4.2 FSI

Email or Call us at 203-483-6100 for Best Price

MS100091
APR Valve Spring System For 4.2 FSI V8
Pricing: $1,199.99

Qty:
Free Economy Shipping to Cont 48 US

Description

Key Components and Benefits

  • 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 valve float 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
  • Valve Springs

    Weight reduction, and not necessary stiffness, is absolutely necessary to increasing valve control. The APR Valve Spring utilizes a beehive design that allows for a reduction in mass in not only the spring itself, but also through use of a smaller titanium retainer. The springs feature an ovate wire design that allows for even stress distribution resulting in better control at high RPMs through a resistance of harmful valve float inducing harmonics. The lightweight design also accomplishes accurate valve control without requiring an overly stiff spring which has been proven to snap OEM valves in half. Each valve spring weights 29 grams and represents a 19% weight reduction over the OEM Golf R spring. The result is a highly engineered design that's simply plug and play!

    Valve Spring Retainers

    Through the use of a beehive design, APR's Engineers were able to design and supply a valve spring retainer that's smaller than stock to reduce weight as much as possible. In an effort to offer extreme weight savings, at an additional 71% over the OEM Golf R retainers, American 6AL4V titanium was used for its high specific strength weighing in at only 2 grams each. By offering outstanding weight savings, exceptional valve control characteristic are achieved while only requiring a modest 20% increase in stiffness over the OEM Golf R spring.

    Valve Spring Seats

    Often an overlooked piece of an upgraded valve train is the valve spring seat. The factory heads are aluminum, and unfortunately increased spring pressure can distort or erode the mating surface overtime as they mate directly to the bare head. To prevent this from happening, APR's Engineers designed valve spring seats out of 4140 heat-treated chrome molly steel with a black oxide coating. The spring seats are strong enough to withstand pressure from the springs and provide a mating surface that evenly distributes spring load across a larger area than the spring it'self, allowing an increased spring rate without negative side effects to the aluminum head.

    Eliminating Valve Float

    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.

    Extended Fitment Details

    ~

    This product fits the following vehicle configurations:

    YEARSMAKE MODELSUBMODELENGINEFUEL TYPEASPIRATIONENGINE CODENOTES
    2000-2011AUDIA6 QUATTROALLALL/ALLALLALL
    2013-2014AUDIA8 QUATTROALLV8/4.0ALLTALL
    2011-2012AUDIA8 QUATTROALLV8/4.2ALLALLALL
    2007-2010AUDIQ7ALLV8/4.2ALLALLALL
    2008-2014AUDIR8ALLV8/4.2ALLALLALL
    2007-2008AUDIRS4ALLALL/ALLALLALL
    2013-2014AUDIRS5ALLALL/ALLALLALL
    2014-2014AUDIRS7ALLALL/ALLALLALL
    2008-2012AUDIS5ALLV8/4.2ALLALLALL

    Details

    Categories

    Shipping Information

    • Item Requires Shipping
    • 6.0 lbs.
    • W7.0000” x H5.0000” x L9.0000”
    • Free Economy Shipping to Cont 48 US

    Customer Reviews

    Comment Total Reviews (0)

    Write the First Review!

    You must login to post a review.