Manual for the HKS VPC (Vein Pressure Converter)
I found this in my archives and somebody may be looking for this so I’m adding it to my blog posts.
The HKS VPC is a fuel management device that is designed to physically and electronically replace the OEM air metering devices for improved air flow and precise fuel delivery control. OEM air metering devices, such as Air Flow Meters (Flapper/Plunger types) and Air Mass Sensors (Hot wire / Karmen Vortex types) measure the amount of air flowing into the intake manifold in order to properly control fuel enrichment levels.
Aside from offering no adjustment or reprogramming options to take advantage of dramatically higher amounts of airflow or larger fuel injectors, the OEM air meter also represents a significant restriction to the intake system. To overcome this restriction, the VPC physically removes the OEM air meter to dramatically improve airflow capacity and converts the system to what is referred to as a speed density system.
By utilizing a 16-bit central processing unit, the VPC reads it’s own intake air temperature sensor and absolute pressure transducer (B-MAP sensor) signals and then converts those signals to one that is recognizable by the factory ECU. The VPC also incorporates the ability to upgrade the internal application specific ROM program to correctly compensate and take full advantage of larger, Higher flowing, HKS fuel injectors and/or the greater air flow characteristics of larger turbos. Each application specific ROM program is calibrated for a specific injector size, fuel pumps, camshafts, and/or turbos, ensuring that the correct injector pulse width is calculated to prevent driveability and reliability problems.
Since the VPC “piggy-backs” the factory ECU, all factory systems are still intact and operational. Fine tuning of fuel curves can be further achieved by integrating the plug-in GCC or by wiring in a Super AFR.