Shadow E-Drive 4S Throttle Controller

The Shadow E-Drive 4S electronic throttle controller allows you to customize the throttle response on your Subaru. If you are a Mach V Motorsports fan, you know we are skeptical of this kind of thing, and we would not sell it if we hadn't tested it on our own cars. This controller DOES work, and does do what it claims. 

The E-Drive consists of two main parts, which are a control box that will hide under the dash, and a display/input device that you will mount where you can see and interact with it. The kit includes an easy plug-and-play wiring harness that installs between your throttle pedal and the car's wiring harness. Installation is very easy and can be completed in under 20 minutes.

Features that we have observed and can confirm ourselves:

• There are three basic modes: Performance, Eco, and Normal. Performance mode increases the sensitivity of the throttle, increasing throttle opening relative to pedal opening. Eco mode reduces throttle sensitivity. Normal mode bypasses and delivers factory throttle response.
• Within Performance and Eco mode there are several levels to choose from, ranging from 1 to 9 on Performance and 1 to 7 on Eco. 1 is minimal effect, and the higher numbers are maximum effect.
• There are also some extra features, including Anti-Slip, Anti-Theft (basically disables the throttle), and Drag Racing mode.
• A live data display shows the pedal input graphed against the throttle opening, using red LED dots. It appears to be accurate and we found it easy to understand.
• Soft silicone buttons feel good to the touch and are easy to understand.
• The compact display unit is easy to mount and fits in just about any car.
• Installation requires no cutting of wires and can easily reversed.

Features that Shadow boasts about that we cannot verify and have to take their word for:

• The processing rate of the electronic throttle controller reaches 1000 times per second, which improves the throttle sensitivity.
• The digital-to-analog converter improves the accuracy of electronic signals, makes the ECU easy to identify and increases the stability of the throttle.
  

If your car has been reprogrammed (by a Cobb Accessport, for example), you may already have recalibrated throttle curves. Also, if you have an STI or other Subaru with SI Drive, your car's ECU will change throttle mapping between modes. The Shadow E-Drive throttle controller can still be used along with those modes, so you could (for example) reduce the aggressiveness of the Sport# throttle mapping, or increase the throttle response of Intelligent mode, on the fly. It's fun!

We have tested this unit fairly extensively and it has worked consistently. We were able to trigger throttle-related Check Engine Lights at times when we experimented with the Anti-Theft mode. (The ECU maybe doesn't like it when the throttle body does not open at all even thought the throttle is pinned.) We were able to clear those codes without further problems, but we might suggest not buying the throttle controller if the Anti Theft function is your only reason to buy it.

We particularly like this controller on BRZ/FR-S/GR86 cars, which up through the 2024 model year didn't come with any kind of mode switch to change throttle behavior. 

The kit comes with the controller, display unit, the plug-and-play Subaru-specific wiring harness, adhesive mounting strips, and a paper instruction manual.

Fits all late-model throttle-by-wire Subaru cars. Not applicable to older cable throttle cars like the 2002-2005 WRX.