When it comes to achieving peak engine performance, especially in high-stakes motorsport or heavily modified street applications, the engine control unit (ECU) is the undisputed brain of the operation. The AEM Infinity 708 series stands as a top-tier choice for professional tuners and serious enthusiasts who demand absolute precision and control. This powerful ECU platform manages everything from fuel and ignition to advanced features like individual cylinder control and onboard data logging, making it a cornerstone for competitive builds.
However, the “best” Infinity 708 ECU for your project isn’t a one-size-fits-all proposition. Your choice depends heavily on your vehicle’s make and model, your performance goals, and whether you’re building a custom harness or need a plug-and-play solution. This roundup breaks down the key options, from complete engine management systems to essential accessories, to help you select the perfect component for your high-performance setup.
Our Recommended AEM Infinity 708 Engine Management Solutions
- bOOST MONKEY Replacement Pins FOR AEM Infinity 6 8 8H 10 12 Main Connector
- AEM Infinity 708-301B ECU & Wiring Harness Kit
- AEM Infinity 708-301 ECU Engine Management System
- AEM Infinity 708-302B Plug-in ECU for Nissan 350Z/G35
- AEM Infinity 708-302 Plug-in ECU for Infiniti G35
- AEM Infinity 708-303B Plug-in ECU for Nissan 370Z/G37
- AEM Infinity 708-304B Plug-in ECU for BMW E46 M3
- AEM Infinity 708-305B Plug-in ECU for Subaru WRX/STI
bOOST MONKEY Replacement Pins FOR AEM Infinity 6 8 8H 10 12 Main Connector
Even the most advanced ECU is useless without a reliable electrical connection. This set of 120 replacement pins from bOOST MONKEY is a crucial accessory for anyone building or repairing a custom wiring harness for an AEM Infinity ECU. These pins are designed as a compatible replacement for the main harness plugs, ensuring a perfect fit and secure connection for all critical engine signals and power feeds.
Having these pins on hand is invaluable for professional installers and DIY builders alike. They allow for the correction of wiring mistakes, the repair of damaged connectors, or the creation of a completely custom loom from scratch. The high-quality construction helps maintain signal integrity, which is essential for the precise data the Infinity ECU requires to manage your engine effectively.
AEM Infinity 708-301B ECU & Wiring Harness Kit
For those embarking on a custom engine swap or managing a race car with a non-standard engine, the 708-301B kit is the ultimate starting point. This package includes the powerful Infinity 708 ECU along with a universal wiring harness. The harness is supplied with loose wires, giving the installer complete freedom to configure the pinouts and sensor connections exactly as needed for a specific application.
This kit provides the maximum level of flexibility and control, making it a favorite for professional motorsport teams and custom fabricators. You are not limited by a pre-defined vehicle application, allowing the ECU to be tailored for everything from a classic car restoration with a modern engine to a dedicated track machine. It represents the full, unbridled potential of the Infinity 708 platform.
AEM Infinity 708-301 ECU Engine Management System
The AEM Infinity 708-301 is the core Engine Management System unit, typically sold without a harness. This is the ideal choice if you already have a compatible harness or are sourcing one separately. It contains the same advanced processing power and features as the kit version, including support for virtually any engine configuration, from simple 4-cylinders to complex V8s and rotary engines.
This standalone unit offers all the professional features the Infinity series is known for, such as closed-loop lambda control, high-speed data logging, and powerful traction control strategies. By purchasing the ECU alone, you have the option to pair it with a custom-made harness from a specialist or use an existing one, providing a modular approach to your engine management setup.
AEM Infinity 708-302B Plug-in ECU for Nissan 350Z/G35
For owners of the popular Nissan 350Z and Infiniti G35 (VQ35DE engine), the 708-302B offers a perfect blend of high-end performance and installation simplicity. This is a plug-in ECU, meaning it is designed to connect directly to the factory engine harness. This drastically reduces installation time and complexity, eliminating the need for custom wiring and saving countless hours of labor.
Despite the straightforward installation, this ECU does not compromise on capability. It replaces the factory computer entirely, providing full control over fuel, ignition, and all other engine parameters. This allows for significant power gains, especially when paired with aftermarket turbos, superchargers, or other performance modifications, all while maintaining a clean, OEM-like installation.
AEM Infinity 708-302 Plug-in ECU for Infiniti G35
Similar to the 708-302B, this 708-302 variant is engineered specifically for the Infiniti G35. As a plug-in unit, it maintains all the stock driveability and accessory functions while opening the door to advanced tuning and power optimization. The primary benefit is the seamless integration with the vehicle’s existing electrical system, making it a reliable and sophisticated upgrade.
This ECU is an excellent solution for G35 owners looking to push their vehicles beyond the limits of the factory tune. It provides the robust platform needed to support major engine upgrades, including custom camshafts, high-flow fuel systems, and forced induction. The plug-in nature makes it a practical choice for both daily drivers and weekend track cars.
AEM Infinity 708-303B Plug-in ECU for Nissan 370Z/G37
Taking the VQ platform to the next level, the 708-303B is the designated plug-in solution for the Nissan 370Z and Infiniti G37 (VQ37VHR engine). This ECU is calibrated to work with the specific sensors and outputs of these vehicles, ensuring compatibility and performance. It allows tuners to fully exploit the potential of the VQ37’s dual intake and exhaust system.
With this ECU, owners can address common limitations of the factory ECU, such as restrictive torque management and conservative ignition timing. It enables precise control for naturally aspirated builds and provides a solid foundation for forced induction projects, all through a direct plug-in connection that preserves the vehicle’s original wiring.
AEM Infinity 708-304B Plug-in ECU for BMW E46 M3
The BMW E46 M3 is a legend in the sports car world, and the 708-304B is designed to unlock its full potential. This plug-in ECU replaces the factory MS54 DME, providing superior control over the high-revving S54 inline-six engine. It is an ideal upgrade for track-focused M3s or heavily modified street cars where the stock computer becomes a limiting factor.
This unit offers features the factory ECU lacks, including individual throttle body synchronization, more advanced traction control, and the ability to properly tune for aftermarket individual throttle bodies or forced induction kits. It maintains communication with the instrument cluster and other vehicle modules, ensuring a fully integrated and high-performing engine management solution.
AEM Infinity 708-305B Plug-in ECU for Subaru WRX/STI
Subaru WRX and STI models from 2008 to 2014 are known for their tuning potential, and the 708-305B plug-in ECU is built to handle it. This model interfaces directly with the factory harness of these turbocharged boxer engines, offering a robust platform for significant power increases. It effectively replaces the need for a collection of piggyback controllers and reflashes with a single, comprehensive solution.
For builds involving larger turbochargers, upgraded fuel systems, and built engines, this ECU provides the precise tuning resolution and safety features necessary for reliable power. It allows for complete control over parameters like boost-by-gear, launch control, and flat-foot shifting, turning a potent all-wheel-drive platform into a finely tuned performance machine.
Buying Guide: What to Look For in an AEM Infinity 708 ECU
So, you’re thinking about an AEM Infinity 708 for your engine management project. It’s a serious piece of hardware, and making sure it’s the right fit is key. I’ve spent a lot of time with these units, and here’s my take on what you should consider before you buy.
First, you need to be honest about your goals. Are you building a weekend track toy, a high-horsepower drag car, or a complex all-wheel-drive project? The Infinity 708 is incredibly powerful, but that power comes with complexity. If you’re just looking for a simple plug-and-play upgrade for a mildly modified street car, this might be overkill. It really shines when you need its advanced features like individual cylinder tuning, built-in data logging, and support for complex transmission control or boost-by-gear. Think about what you actually need now, and what you might need in the future.
Next, let’s talk about the installation and tuning process. This isn’t a simple “chip” you plug in. You’re replacing the entire brain of your engine. You’ll need a capable tuner who is fluent with the AEM software. I can’t stress this enough. A bad tune on a powerful ECU can cause serious engine damage. Before you even buy the ECU, I recommend finding your tuner. Have a conversation with them. A good tuner will help you decide if the Infinity 708 is the right tool for your build and can often provide invaluable advice on sensor selection and wiring.
You also have to think about the harness. You can buy a pre-made harness for many popular applications, which saves a massive amount of time and potential wiring headaches. If your car isn’t listed, or you’re doing a custom swap, you’ll be building a harness from scratch. This requires a good understanding of automotive electrical systems. Don’t underestimate this task. A messy or incorrect harness can lead to frustrating electrical gremlins that are very hard to diagnose.
Finally, consider the total cost. The price of the AEM Infinity 708 ECU itself is just the beginning. You need to budget for sensors, a wideband oxygen sensor, potentially a new harness, and most importantly, professional tuning time. When you add it all up, it’s a significant investment. However, for a build that demands precise, professional-level engine management, the control it offers is unmatched. It’s an investment in total control and reliability for a high-performance engine.
FAQ
What kind of vehicles is the AEM Infinity 708 best suited for?
I see the Infinity 708 as a tool for serious performance builds. It’s perfect for dedicated race cars, high-horsepower street-legal track cars, and complex engine swaps where the factory ECU just won’t cut it. If your project involves things like forced induction, nitrous oxide, individual throttle bodies, or you’re chasing every last horsepower with precise individual cylinder control, this is your ECU. For a basic daily driver with simple mods, it’s likely more than you need.
How difficult is it to tune the Infinity 708 myself?
This is a common question. The AEM software is powerful and logical, but it has a steep learning curve. If you’re completely new to engine tuning, I would not recommend starting here. It’s not impossible to learn, but you need a solid foundation in engine theory and a willingness to study. Mistakes can be expensive. For most people, especially for a complex setup, hiring a professional tuner is the safest and most effective path. You can, however, use the software to do basic things like data logging and viewing parameters, which is a great way to learn.
Can it control an automatic transmission?
Yes, absolutely. This is one of its standout features. The AEM Infinity 708 has dedicated inputs and outputs for controlling many popular electronic automatic transmissions, like those from GM, Ford, and others. This means you can have a single, integrated ECU managing both your engine and transmission, allowing for features like custom shift points, torque management, and launch control. This integration simplifies the wiring and tuning process significantly for an auto-equipped car.
What’s the difference between the Infinity 708 and a simpler AEM ECU like the Series 2?
The main difference boils down to inputs, outputs, and processing power. The Series 2 is a fantastic ECU for most high-performance street and track applications. The Infinity 708 takes it much further. It has more analog and digital inputs, more high-current driver outputs, faster processor speed, and supports more advanced features like direct injection and complex closed-loop control strategies. Think of the Series 2 as a very sharp chef’s knife, while the Infinity 708 is the entire professional-grade knife block.
Do I need any special hardware to connect it to my laptop?
You will need a way to connect the ECU to your computer for tuning and data logging. AEM uses a specific device called a CAN-USB adapter. This isn’t a standard USB cable; it’s a communication interface that translates the data between the ECU and the AEM tuning software on your laptop. Make sure you factor this adapter into your purchase, as you can’t do anything without it. Some kits may include it, but often it’s a separate item.