Boost Controller: A'pexi AVC-R

We hit the dyno with 6 boost controllers and a ball valve.

A'pexi suggests having the AVC-R installed at one of its authorized Power Excel Shops. This might be a good idea, as splicing into the car's ECU harness to intercept engine speed/injector pulse width, throttle position, speed, power and ground are required to get the most out of the unit. Wiring in a momentary switch, which is not provided, is also required to take advantage of the scramble mode. If you're comfortable digging through the dash, and making good clean electrical connections, you should have no trouble installing the unit yourself. A'pexi includes ECU pin-out diagrams for most popular Japanese makes.

A single solenoid regulates the signal going to the wastegate, and a separate MAP sensor can be placed wherever it's convenient. The quality of the components is first rate, with waterproof connectors used for all engine compartment junctions. About the most annoying thing in the world is not having the right vacuum "T" fitting when trying to install your new toy at 1 a.m. A'pexi comes through with a vast goodie-bag of tee fittings and hose clamps. Also of note are the vehicle-specific install diagrams for the twin-turbo Supra and RX-7, which interestingly recommend rerouting the turbos to run in parallel.

The control unit itself is handsome, with a huge vacuum fluorescent display that's easily viewed from all angles and auto-dims in low light conditions. Contrast is adjustable from a submenu. An adjustable bracket simplifies mounting on uneven surfaces.

Basic programming and operation are straightforward with a little guidance from the 57-page English manual. The menu-driven interface is clear and intuitive. A'pexi has put a considerable effort into documenting its product and it shows. The two boost settings can be independently programmed, retained, and switched between as desired. Boost can either be set at a fixed level, or allowed to vary with rpm. Additionally, a separate scramble configuration is available for each setting to raise or lower the boost at the touch of a button (any button you want, as the unit just looks for a signal wire to be grounded).

Monitor mode provides a number of methods to display and log all the sensor data available to the AVC-R. A maximum of four digital numbers, two simulated analog dials, or a single line graph can be displayed. Maximum log time is 60 seconds. A peak hold function is also available for all displayed data.

Out of the box the AVC-R worked fine on our Eclipse. Boost response was good, but as we tried for more, things got a little weird. Getting the most out of the unit takes either lucky guessing, or real tuning time. First you set the boost, then duty, Ne-point, F/B speed... While the AVC-R is supposed to tune itself, it seems the brunt of the work is on your shoulders. If you like to fiddle with things, you'll be in heaven.

Controller: A'pexi AVC-R
Pro: Big display, tons of features, works great.
Con: Must splice ECU harness. Takes time to program well.
Cost: $629
Source:
A'PEX Integration Inc.
(714) 685-5700
www.apexi-usa.com
Aesthetics: Nice big display, simple interface, clean design, big buttons.
Ease of installation: Splicing wires into a ECU harness can get hairy, but the instructions show wire locations for most Japanese cars. Installation instructions available on the company's Web site.
Clarity of instructions: Big fat book in English. Diagrams and flowcharts are intuitive.
Features: Fixed boost, rpm-based boost control, scramble up and down, auxiliary instrumentation for rpm, speed, TPS, duty cycle, boost. Data logging and replay, peak/hold display.
Support: Good on phone, answered questions.