Emissions Warning: This product is not designed for public highway or street use, and is only legal for formally sanctioned race use on a racing vehicle that may never be used on a public highway or street.

COMES WITH ALL PISTONS FOR YOUR ENGINE (WITH RINGS, LOCKS, AND WRIST PINS INCLUDED). Piston sets without any special notes are for stock bores - oversized bore pistons will be labeled as such. Each set is matched at CP to be evenly weighted and dimensionally identical. Additional oversize piston options can be ordered for some applications (contact us with your requirements if needed).

CP Pistons are known to be some of the strongest pistons available for your BMW X4 M. If you're looking to add more power to your car, CP Forged Pistons are a great way to help build your motor to handle it. Available in multiple compression ratios and standard or oversize bores, CP makes a piston to handle whatever your plans are. From high compression high RPM screamers to low compression, high boost race applications, or even nitrous, CP has built a piston that will hold up to it.

Each piston starts out by being 3D modeled in advanced computer software, and then subjected to a rigorous Finite Element Analysis to confirm the piston is strong where it needs to be, yet lighter where it can be. This leads to some of the lightest and strongest pistons available. Once the piston has been designed, they are manufactured using state of the art 5 Axis Machining techniques and measured by demanding quality control procedures to ensure each piston meets exact specifications for your application. CP has many features standard on every piston they make to create the best performing pistons available.

Key Features:

• Anti-Detonation Grooves protect the top ring of piston by disrupting the pressure waves created by detonation. These grooves also have the effect of minimizing piston to wall contact during high RPM and high load situations, resulting in less frictional loss and quieter operation.
• Using an Accumulator Groove between the top and middle rings helps prevent any excess blow by from disrupting the top ring seal due to fluttering which happens on other piston designs.
• Double Pin Oilers help additional oil reach the wrist-pin extending the life of the piston and easing the load on the rods and crankshaft.
• Radiused Domes eliminate potential hot spots by smoothing the transition from any variations in the face of the piston. With no sharp peaks or valleys to act as hot spots, the detonation threshold is raised significantly.
• X-Forging techniques (on some applications) allow a lighter piston with less friction by crating pistons that use bracing and internal ribs to create the stiffness needed to perform. This allows CP to adjust the balance of the piston by moving the weight where it is needed, and away from where it isn't. This not only makes a lighter piston, but also allows for use of a shorter wrist-pin which eliminates even more weight.
• Proprietary MIL (Maximum Internal Lightening) machining process to eliminate excessively thick piston faces on contoured designs. By keeping an even face thickness the pistons are not only lighter, but distort less under heat and are more stable.
• Ultra-high strength aluminum forge.
• Custom skirt cam and barrel design.
• Large, deep valve reliefs for +1mm valve sizes and high lift camshafts.
• High performance piston rings.
• Fully CNC machined and balanced to +/- 1 gram.

Fitment Notes: Some applications will not work with your stock connecting rods. For example, if you factory rods are "Pressed Fit" onto your pistons, you must purchase aftermarket rods with these CP pistons. We always recommend a set of aftermarket rods to avoid this. Aftermarket rods will also hold additional power over the stock rods, allowing you to really take advantage of your new CP Pistons.

Compression Ratio Notes: In general, lower compression pistons below about 10.0:1 compression are used in forced induction setups (turbo/supercharger/nitrous) and higher compression pistons above about 10.0:1 compression will offer more power in naturally aspirated engines (and can sometimes still use nitrous)