What was even more impressive...
What was even more impressive than the added horsepower was the increase in torque. Peak torque now checks in at 335.6 lbs-ft compared to the 280.4 lbs-ft baseline. The largest increase in torque was also realized at 4900. An increase of 58.3 lbs-ft of torque was registered.
Although manual boost controllers are often inexpensive to purchase and easy to install there are drawbacks. There are no load, altitude or density corrections and most manual boost controllers lack consistency from gear to gear. More importantly manual boost controllers are known to cause boost spike, which can lead to severe engine damage. Manual boost controllers can also hinder low and mid-range response.
A'PEXi AVC Type-R Electronic Boost Controller
Unlike manual boost controllers that utilize a mechanical regulator/relief valve to control boost, an electronic boost controller utilizes an electronic solenoid valve or in some cases a stepper motor for boost control. The electronic solenoid valve is linked to a microprocessor box that determines how long the solenoid stays open (duty-cycle). The electronic solenoid regulates the amount of air relieved to the atmosphere away from the wastegate or wastegate actuator so higher boost pressure can be realized. With the help of the microprocessor box and information gathered by the pressure sensor the electronic solenoid is commanded to open and close for a specified time to obtain the optimum boost curve. The electronic solenoid can be run in-line for actuator-type wastegate or T'd for external type wastegate. The microprocessor also receives information from an additional pressure sensor to also help determine the duty cycle of the solenoid valve.
Setting Mode
Like many electronic boost controllers A'PEXi AVC Type-R utilizes a microprocessor box, electronic solenoid valve and pressure sensor for boost control. However, unlike other electronic boost controllers the AVC Type-R unit incorporates self-learning mode as well as scramble boost, rpm boost correction and gear based boost control.
The monitor mode allows up...
The monitor mode allows up to four different data channels to be viewed in three different ways-numerical, analog meter and graph display.
The AVC Type-R is capable of two preset boost levels-channel A and channel B. For example, one can be used for a low-boost setting ideal for everyday driving and the second channel can be used as a high-boost setting for drag strip duty. Turning off the AVC-R unit deactivates the AVC Type-R's solenoid valve and boost control will be regulated by the wastegate spring or actuator.
In the setting mode the user is allowed to adjust the desired boost pressure and solenoid duty cycle. Both boost and solenoid duty-cycle are adjustable by the tuner at the selected eight-rpm points. The tuner can adjust the eight-RPM points between 1500 and 9500-rpm in 500-rpm increments. By allowing boost and solenoid duty cycle to be adjusted at eight different rpm points the boost curve can be custom tailored by the tuner.
Each preset channel can also incorporates a scramble boost feature. By adding a momentary switch, boost pressure can be increased or decreased for a certain amount of time. The user can also choose to increase or decrease solenoid duty cycle to further control the boost pressure rate. This feature is especially beneficial to traction-limited vehicles.