Cobb Tuning Dual Bypass Valve Kit — R35 GTR

Description

The COBB XLE BPV is a compact and lightweight by-pass valve that is capable of holding very high boost pressure without leaking. Its unique design allows for extremely fast venting of boost when actuated. It is designed to operate in multiple venting modes and can be quickly reconfigured using simple hand tools. Innovative engineering and precision manufacturing result in a compact package able to fit in the confines of a tight engine bay.

Body
Body, mounting flange and secondary outlet cover are constructed of 6061 T6 aluminum.
The body is hard anodized for additional strength.
The primary outlet is rectangular in shape to provide maximum cross sectional area for venting pressurized air as quickly as possible.
The secondary outlet cover can be removed to enable partial vent to atmosphere or full vent to atmosphere modes.
Unit height is only 3.5 inches from base of flange to top preload adjuster,allowing it to fit into the tightest of locations.
Body to mounting flange interface is o-ring sealed, allowing flanges of different shapes to work on multiple applications.

Piston
Lightweight aluminum piston allows faster reaction time than heavier pistons.
The aluminum piston has been hard anodized and impregnated with Teflon to provide smooth movement, reduce surface wear and minimize maintenance.
Rounded piston profile smooths air flow as it passes through the cylinder.
The rounded piston profile mates with a rounded piston seat for superior sealing when the BPV is closed.
Tight tolerance o-rings are used to seal piston to cylinder bore properly at normal engine operating temperatures without sacrificing piston speed.

Preload Adjuster and Spring
Adjuster allows adjustment of spring preload for fine tuning release pressure.
Spring and spring seat are constructed of 304 stainless steel.
Spring preload adjustment mechanism and fasteners are stainless steel.

Operation
Valve vents pressurized air very quickly due to lightweight components, port shape and low sliding friction.
Unique exhaust sound due to speed of air release.
Construction materials make the XLE BPV compatible with alcohol/water injection due to inherent corrosion resistance.
Lighter than most aftermarket BPVs and BOVs.

OPERATING MODES

Full Recirculation – Outlet is plumbed back into the intake tract pre-turbo. This configuration provides the best driveability with stock based MAF systems. This configuration generates the least amount of noise.

Hybrid Mode – Outlet is plumbed back into the intake tract pre-turbo and the auxiliary port cover is removed. When the piston is more than 30% open, the auxilliary port is opened, audibly venting to atmosphere. Less than 30% opened results in full recirculation to improve driveability.

Full Atmosphere – Outlet and auxiliary port are open to atmosphere. Recommended only for MAP based air metering. This configuration generates the highest sound levels.

ADJUSTMENT

Spring Preload – Spring preload determines the pressure differential across the BPV piston required before the BPV opens and releases the pressurized intake charge. The COBB XLE BPV can be adjusted by loosening the locknut and turning the allen-head shaft clockwise for more preload or counter-clockwise for less preload. Once preload is set, the locknut is retightened and ensures the adjustment is secure.

Additional information