Holley Avenger EFI
It's only fitting that the company that invented the most popular performance carburetor platform of all time now offers the next logical evolution in fuel delivery with its new Avenger EFI systems. That company is Holley, and its self-tuning EFI systems are available in three different configurations. The entry-level unit (PN 550-400) comes equipped with a 700-cfm throttle-body and 65-lb/hr fuel injectors, the midrange model (PN 550-401) has a 900-cfm throttle-body and 75-lb/hr injectors, and the top end system (PN 550-402) includes a 900-cfm throttle-body and 85-lb/hr injectors. The respective models are good for a maximum of 400, 525, and 600 hp, respectively.

Like competing systems on the market, the Avenger EFI is a direct bolt-in replacement for any square-bore carburetor and just about anyone can install it in a single afternoon. Holley went the extra mile with several distinguishing features such as ignition timing control that's compatible with most aftermarket distributors, and an extremely powerful ECU. "The Avenger ECU is the same unit used in the Holley HP EFI system. That means it has the capability to control nitrous, boost, multipoint injector setups, and coil-on-plug ignition systems," Holley's Bill Tichenor explains. "You can simply hook the Avenger ECU up to a laptop and access these functions. Although Avenger users won't use many of these advanced features, the ECU can grow with you if you change your engine combination in the future. This same ECU is used on race cars making thousands of horsepower, so there is no need to upgrade it."

If that sounds too advanced for your liking, don't worry. For the electronically challenged, Avenger EFI systems include a handheld controller that walks you through an extremely simple initial tuning process. "All you have to do is answer some very basic questions pertaining to displacement and camshaft size on the handheld controller, and the system creates a base tune for you," Tichenor says. "Then you just start the car and drive while the computer begins the self-learning process once the motor reaches operating temperature. You can also make simple increases or decreases to the idle speed, rev limit, and air/fuel ratio."

"All you have to do to create a baseline tune is answer a few simple questions using the handheld controller." —Holley's Bill Tichenor

By The Numbers
What's included: throttle body, ECU, injectors, wiring harness, oxygen sensor, handheld controller, EFI software, fuel system
Max power: 400-600 hp
Injector size: 65, 75, or 85 lb/hr
Base kit PN: 550-400, 550-401, and 550-402
Optional items: multipoint Avenger system (PN 550-811)
Dealer network: yes, visit website for details
Street price: $2,059