NitroStick Series Valve Springs are revolutionizing MINIs performance with street/strip applications. The NitroStick Series Valve Spring and Retainer kit is the first and only valve spring kit designed specifically for the Tritec Mini Cooper engine. Titanium retainers reduce inertial load, allowing optimal performance for high RPM and high lift camshaft applications. The NitroStick Spring and Retainer kit is for street and track applications and is the best choice possible for your MINI. The unique Beehive design allows the valve train to handle higher engine rpm and more aggressive cam profiles with even a full race MINI engine but still retain reliability for street driving.

Features
Bee Hive Geometry
The Bee Hive Geometry has several benefits: Beehive valve springs have been known in the industry as having a lower mass at the retainer end thus allowing for better valve control. Beehive valve springs are unique when it comes to coil spacing and rate control,

Oval Wire
Unlike many conventional springs, the NitroStick valve spring is wound with oval wire. This results in more even stress distribution in the spring, and allows for a higher maximum lift.

Ti Retainers
The Ti retainers are custom manufactured for the Tritec MINI application. Ti is a lighter mass material than steel, reducing inertail effects and valvetrain loading.

Specifications
1.061" Outside Diameter
0.550" Max Lift
1.020" Coil Bind
37.3 g Spring Weight
110 lbs @ 1.650" Seat Force

Fits these MINI models:
R52: 2004-2008 Convertible: Cooper S
R53: 2002-2006 Hatchback: Cooper S

Priced individually