The XEDE - Subaru Impreza WRX

The WRX XEDE: An Overview

The XEDE (pronounced "ex-eed") is the only user-programmable engine control system that works with the factory ECU- not instead of, or against it. Every one of its functions has the resolution and flexibility to complement all factory ECU engine control strategies. From the factory ECU's boost-limiting safety features, to its active timing control, to its dual fuel maps, to its long-term learning algorithms, etc., the XEDE carries the tuning torch without inducing any compromise to performance or safety margin. A year ago, such coherence between ECU and interceptor-based tuning device would have been deemed impossible for a number of reasons:

1) No one had access to underlying fuel, timing and boost maps. This means that all piggy-back tuning attempts were subject to unknown. Variables that had influence over long-term fuel learning or knock correction. It was also impossible to determine and compensate for maximum RPM or Load limits which made extracting full performance without concessions to safety margin virtually impossible.
 

2) Limited resolution with respect to tuning control. With the factory fuel, timing, boost and knock correction maps offering up to 16x16 cell resolution with engine speed breakpoints every 400RPM, no interceptor-based tuning device of the time offered commensurate resolution. Without this resolution, it was impossible to compensate for sudden spikes or dips in underlying maps. Instead, compromise was inherent in such applications.
 

3) Poor crank angle sensor (CAS) replication. Prior interceptor-based tuning systems improperly replicated the crank angle sensor waveform, maintaining little more than signal peaks and valleys. While this was sufficient to manipulate basic timing advance, it often triggered factory diagnostic strategies, hard-starting, erratic knock correction and general rough-running characteristics.
 

4) Limited tuning software flexibility. As with virtually every aftermarket engine control systems on the market, tuning software interfaces offered resolution greatly inferior to that of the factory ECU it is attempting to influence. With the inability to place Load and RPM breakpoints wherever necessary for coherent management (and the restriction of having to use the same Load and RPM breakpoints for all tuning variables) the tuning process was shrouded in compromise.
 

The XEDE addresses all the above issues as following:

1) With our involvement with the ECUTEK re-flashing system, we now have full knowledge of all OEM fuel, timing advance, knock correction, etc,. maps. Knowing all underlying engine control variables, it's now possible to know exactly what one is tuning upon.

2) With the XEDE offering an ultra-high 20x20 map resolution, it is now possible to tune upon the factory maps without sacrificing granularity or having to compromise one zone for another. Additionally, XEDE users can define not only their own Load and RPM breakpoints for each map, they can also determine which Load variable to use (TPS, MAP or MAF) in order to best achieve their specific tuning goals. Simply put, no other form of engine management offers this degree of tuning flexibility.

3) Compared to the Unichip, the XEDE is capable of vastly superior CAS replication. This ability greatly improves active knock correction performance, general drivability and invisibility to the factory diagnostic system. Perfect CAS replication insures that there is absolutely no misunderstandings between the factory ECU and the XEDE.

4) Unlike the Unichip which is capable of modifying only Ignition Timing and MAF signals with fixed load (MAP) and RPM) breakpoints (every 500RPM, the XEDE is capable of modifying Ignition Timing, MAF, TPS, MAP and Knock sensor signals with respect to RPM (up to 20 user-definable breakpoints) and any one of three Load variables (MAP, TPS or MAF).

5) Unlike the S-AFC, the XEDE is capable of providing boost and spark timing control in addition to high resolution fuel management. Used appropriately, this enhanced functionality yields a broader power band as well as a much greater resistance to detonation.

XEDE Technical Specifications

• 1200 possible adjustments on the standard New Age WRX program
• 0.1% accuracy on MAF and MAP adjustments
• 0.1degree accuracy on timing adjustments
• Accurate reproduction of reluctor type timing signals, not just of triggering edge
• Direct plug-in adaptor (no cutting or splicing required)
• Fully sealed, rugged, and lightweight housing
• Support for hall and reluctor type crank and / or cam timing signals
• Support for analog or frequency MAF and MAP / load signals
• One additional 10-bit analog input
• One auxiliary digital input / output
• Internal storage space for up to 12 tuning maps
• Built-in boost control
• Built-in knock signal adjust feature
• Self-configurable load axis, input and output variables, adjustment range, and math function for each map
• 'Map Select' input to change between one of two unique tuning maps
• Two high-current Pulse Width Modulation outputs
• Remotely installable bi-color status LED
   

Introductory Pricing:

XUpdate (.zip) XMAP Full-Functional Tuning Software (.zip file) Allows user to create new, or modify existing, XEDE tuning maps. Only recommended for those who want to tune and understand the consequences of improper engine management calibration.

FREE

Getting Started with the XEDE (.pdf)

Installation Instructions

Click here for directions on how to Upload Maps into your XEDE (.pdf)

 

XEDE Tuning Map Database

Warning: The following calibration maps are designed for WRXs running the factory intake system (stock box, stock filter, stock resonation, etc,.) Replacement of any of these components will result in MAF sensor mis-readings which will result in erratic and possibly dangerous engine performance. All calibration maps are designed for premium gasoline. Anything less will likely induce detonation which will damage the engine.

Notes: The following XEDE maps are designed exclusively for the newest iteration of the XEDE and its associated plug-in harness. This newest iteration offers fully programmable closed and open loop boost control as well as map switching via externally mounted switch. Users of earlier generation XEDE units without these new features are encouraged to contact us for upgrading. This will either involve a hardware update or exchange-both free of charge.

Also, unless otherwise stated, all tuning maps are designed to be used with the Vishnu-supplied black boost line fitting and factory turbo wastegate hoses. Using the wastegate hoses from other turbos (VF30, VF23, VF22, etc,.) will result in boost instability and spiking.

Subaru WRX

Stage: (Click for description)	91 Octane	93 Octane	100+ Octane
V265
V280
V300
V350

Blank map: This map is completely blank. Meaning, if it is uploaded into the XEDE, your car will drive as if the XEDE wasn’t there. There are no fueling, boost, TPS or timing changes. click here

WRX XEDE News and Updates

June 25, 2003
We now have WRX XEDE boost control working in both absolute and intercept modes. In absolute mode, you simply input your desired wastegate duty cycles as a function of load and RPM and your factory boost control hardware does the rest.

In intercept mode, instead of inputting actual duty cycle values, you input offset to stock. For example, if you want 83.6% of factory boost at 5000RPM, you simply put "83.6%" in the 5000RPM cell in your boost map.

In either mode, you have the ability to run a RPM-dependant boost profile of your choice. This is far superior to using a stand-alone boost controller, most of which are only capable of holding one boost level all the way up to redline. Also, the boost control logic in the XEDE greatly improves both low RPM and partial-throttle boost response. Your WRX will never fell the same again (that's a good thing!)

June 27, 2003
Map switching between two maps (both stored in the XEDE) is now ready! Simply hook one of the XEDE wires up to a switch which brings it to grown when activated and the map switch occurs. During map switching, the indicator light will turn red for a couple of seconds indicating that its loading up the secondary map. When the light turns back to solid green, your second map is on-line and you're ready to rock and roll. On our Stage 2 WRX test car, our second map is designed for 100 octane race gas. With it activated, it raises boost pressure, runs more ignition advance and less fueling under boost. Easy extra 20-30 foot-lbs of torque all through the midrange with! No joke.

July 10, 2003
We've incorporated new ignition control logic that limits the rate-of-change of ignition advance changes. What does this mean? Let's say that you have a "0" in one cell in your ignition advance table and "-3" in the adjacent cell. If the cells are placed close enough, the ignition retard will ramp up too quickly and potentially trigger a CEL for misfire detection. We've only seen this happen once or twice (out of 30+ cars) so it's certainly not a chronic problem. Bur our new firmware update limits the rate-of-change for ignition advance changes so that no two successive engine events result in excessive crank angle signal changes. We've also incorporated some rather neat ignition control logic that fixes some quirks in the factory ignition advance mapping/control. The result: More immediate torque upon throttle application.