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Alternatives to Cobb Tuning for Subaru Competition Vehicles


On April 18th, 2022 Cobb Tuning issued a press release notifying their customers that their AccessTuner software and Cobb AccessPort platform would be undergoing significant changes in an attempt to get ahead of increased federal regulatory and compliance mandates. This change would be made across the entire landscape of supported vehicles including Subaru competition, off-road vehicles. I encourage you to read the full update linked here.

What This Means

Many Subaru competition vehicles were able to utilize factory engine management systems including the ECU, with the help of aftermarket software, to permit modifications related to competition such as drag racing, road racing, autocross, time attack, rallycross, and more. These vehicles will no longer be able to utilize the Cobb AccessPort and AccessTuner software on the factory engine management systems. This is due to the fact that many competition vehicles omit certain OEM functions and the removal of these functions is no longer permitted under Cobb's new directives.

What About Non-Competition Vehicles?

Non-competition vehicles will still be able to utilize the Cobb AccessPort and AccessTuner software. Cobb's "Green Speed" plan has aligned their company with the changing landscape of federal regulations in order to ensure that their products and software will be 50-state legal. They are developing new "Stage" packages that retain OEM emissions components but permit modifications in other areas such as intercoolers, air intakes, muffler systems, and more. These packages are being rushed through CARB certification in order to obtain full and transparent legality. 


In short, if you own a road-going Subaru you will largely be unaffected, but there are some items which are sadly no longer being offered, the major one being FlexFuel. This is due to the manner in which FlexFuel sensors communicate with the OEM ECU, which previously was utilizing an emissions-related component. While this implementation did not meaningfully impact emissions controls, Cobb has decided to err on the side of caution and remove this feature from their software. 

Alternative Solutions

The first option that comes to mind would be different software platform that still utilizes the factory ECU as the basis for engine management but adds certain competition features. An example of such software would be EcuTek and their RaceROM feature which includes such motorsports features as boost off the line, map switching, FlexFuel, launch control, flat foot shift, speed density, and per-gear boost control. This allows a competitor who might be more budget-conscious to leverage the existing factory engine management yet still have great functionality.

The next option, and by far the most powerful one, is the use of a standalone engine management system (EMS). These systems are designed specifically to maximize performance, reliability, and data acquisition in competition environments and are used by racers at all tiers of motorsport from entry-level club racers up to Formula 1, NASCAR, IndyCar, etc. These systems are offered by companies like AEM, Haltech, MoTeC, EcuMaster, Emtron, Link, MaxxECU, Bosch, Cosworth, McLaren and others. Contrary to popular belief, standalone EMS are not always cost-prohibitive. They are offered by a range of manufacturers with various product tiers aimed at racers of all types (and all budgets).

In the next section, we'll discuss the standalone EMS option in greater detail, as it is the most feature-rich (and also the most misunderstood).

Standalone Engine Management Overview

Here at BW Tuning we have been installing and calibrating standalone EMSs in competition vehicles for nearly 15 years. In the early days, these systems were expensive, cryptic, difficult to tune, and cumbersome for the customer/racer if they needed to make their own modifications or pull data off the device for review/diagnostics. Nowadays, those concerns are a thing of the past. Manufacturers and technology have come a long way, and there is a product to suit nearly every application.

The primary benefit of a standalone EMS is control... focus on the term "EMS" for a moment. This nomenclature is no accident, it describes the product perfectly. Engine management refers to a system, when properly calibrated, that will effectively and reliably govern the entire series of powertrain events, aggregate key sensor data, provide engine protection or safety measures, and carry out complex logic that the calibrator has built into the software strategy.

Processing Power and Onboard Storage

To carry out this workload, standalone EMSs are often fitted with extremely fast processors and data buses that allow all of this information to keep up with the vast number of inputs and outputs that all factor with one another in real-time. Data can be recorded directly onto the device and analyzed at the pit wall, or in the race trailer, freeing up the driver from managing laptops or SD cards while also trying to operate the vehicle.

Aggregation of Sensor Data

Standalone EMSs are not encumbered by limitations on what types of data they can capture. Any signal, be it digital or analog, can be defined and logged by the system. This gives the racer or engineer full control over which key sensors to fit and in what manner those signals can be used. Some may be utilized purely for logging, for example, a G-meter or brake pressure sensor. Others may be incorporated into the calibration strategy as a key input, where the real-time sensor output is fed back into the system to permit flexibility in the operating condition of the vehicle. An example of this might be a wideband lambda sensor, whose air/fuel ratio value could be used by the EMS to trim (adjust) fueling in real-time.


Engine Protection

Competition racers usually combine expensive/exotic engine components with the harshest operating environments, where sometimes things can (and do) go wrong. For this purpose, engine management systems typically offer engine protection features that allow the calibrator to work with the engineer to determine safe operating limits for the engine and then calibrate the EMS to permit the engine to operate at or below this threshold. Should the engine exceed this threshold, programmed safety measures in different levels of severity can intervene in order to protect the engine. An example of this would be if oil pressure drops to an unsafe level, the EMS can notify the driver and even cut engine RPM to idle speed, an action that might save the engine from physical damage.

Special Sensor Inputs (outside the typical engine sensors) Permitted by Standalone EMS
  • Exhaust Gas Temperature (EGT)

  • Exhaust Manifold Pressure (EMAP)

  • Wideband Lambda (AFR)

  • Coolant pressure/temp

  • Oil pressure/temp

  • Brake hydraulic pressure

  • Clutch hydraulic pressure

  • Turbo shaft speed

  • Wastegate pressure (dome pressure)

  • Nitrous/CO2 bottle pressure

  • Crankcase pressure (pan pressure)

  • Wheel speed/drivetrain speed

  • Shock travel

  • Laser ride height

  • and more

Special Functions Built-in To Standalone EMS
  • FlexFuel

  • Fuel pressure adaptation (and engine protection)

  • Launch control/Anti-lag launch control

  • Flat shift

  • Rolling anti-lag

  • Scramble boost

  • Brake boost

  • Water/methanol injection

  • Nitrous

  • Gear-based control of any parameter

  • User-definable tables

  • Torque management (traction control)

  • Rotational idle

  • and more


CAN (Controller Area Network) Buses are powerful tools found in nearly all standalone EMSs, and they are also one of the least understood by end users.


Simply put, a CAN network allows different devices to communicate along a common bus. Think of a bus as a highway, and the different devices as different buildings placed along the way. Each building has an important function, and they need to communicate with each other. The information they share travels up and down the highway, in a constant hum of activity. This information is always flying along the "highway" and each bit of information has an identifier, just like each car on a highway has a license plate. These packets of information can be read by any device on the bus, and any device can generate its own information and share it with the others. All of this happens simultaneously, and across just a single pair of twisted wires! 

In a practical sense, CAN networks allows EMS manufacturers to cohabitate. Say you have an EMS from Manufacturer A and a digital dashboard from Manufacturer B, you can instruct the digital dash to listen for the specific set of information packets from the EMS so that it can accurately display the engine readings, such as RPM, coolant temp, oil pressure, etc. Conversely, you might have a steering wheel button that is wired up to the digital dash, and that button state can be sent back to the EMS via the CAN network. It's two-way traffic.


It also permits manufacturers to design and sell entire CAN-enabled product lineups that require no manual configuration. For example, Manufacturer A might sell an EMS, a digital dash, a wideband lambda (AFR) sensor, and a 10-button keypad that are pre-programmed to utilize the same CAN networking protocol. For the racer, this means the devices simply plug in to one another and just work. It simplifies the wiring and cuts down on installation time.

Another boon of CAN bus support is that many OEM vehicles utilize CAN networks (starting in roughly 2008). This means that for racers who are choosing to utilize certain factory components such as an instrument cluster, the standalone EMS will enable those devices to continue to function just like they would in an OEM-like configuration.

Preconceived Notions

When it comes to standalone EMS they can sometimes be hated or feared for the wrong reasons. The first is complexity, the second is cost, and the third is livability.


It is a false statement that standalone EMS are too complex. First, your calibrator and tuner should select the proper EMS for the job. It should meet the requirements without being overly complex. Secondly, the calibrator and tuner has a responsibility to educate the racer on how the system will function, and design its capabilities to meet the needs of the owner, not just the vehicle itself.


When it comes to cost, on its face, many standalone EMS have a high price tag. However, the benefits far outweigh the cost. How much do you risk if an engine failure happens that could have been prevented? How much performance are you leaving on the table if you cannot measure the engine vitals holistically? These questions must be answered. Nowadays, many standalone EMS have come down in price and many owners are shocked to find out how competitive the pricing can be.


Vehicle: 2007 Subaru WRX STI

  1. Previous setup: Cobb AccessPort V3, factory ECU, Cobb FlexFuel kit, Cobb fuel pressure kit. Total cost with tuning: $2,295

  2. New setup: Haltech Elite 1500, FlexFuel Sensor, fuel pressure sensor. Total cost with tuning: $2,350

Both setups utilize drive by wire throttle, cam control, FlexFuel, fuel pressure adaptation, etc. The cost difference of the EMS is easily made up by the fact that it doesn't require hoops to jump through to enable FlexFuel and fuel pressure adaptation. Whereas a Cobb kit would previously cost $1,000 to finagle this functionality into a factory ECU, the Haltech system merely requires a $65 Continental/GM sensor and a $70 pressure sensor to do the same thing. The standalone EMS is already head and shoulders ahead in terms of performance, speed, expandability, and the other features touched on previously. It will only continue to expand that gap once the racer starts to add on, and fully utilize the EMS.

(Keep in mind that in the above example, Haltech is just one of many suitable EMS that could perform this task).


Perhaps the biggest false fear is that standalone EMS are harsher or rougher to operate under benign conditions like around the paddock, in the pit lane, or at a slower, constant speed such as behind a pace car. This is not true. In many ways, standalone EMS are far superior to even an OEM road car in terms of low speed manners. This is due again to the sheer amount of control given to the calibrator... you simply instruct the EMS to do something and it does it. There is no fighting with hard-coded programming or functionality, and no workarounds.

As an example, we have a Subaru WRX STI drag race car that routinely competes in "drag and drive" events. These are events that are on closed roads but the drag cars must make a 1000+ mile journey over 5 days, and race each night. Our vehicle has no problem transitioning into this closed road journey on the exact same EMS and calibration. This vehicle is built for racing and has over 1000 WHP on tap yet starts, warms up, drives, and runs BETTER than it did when it came off the lot.


We hope that this article has given you some alternatives to consider when evaluating your plan to continue racing your competition Subaru in the wake of Cobb's product announcement. I know many Cobb customers are probably unsure about how to proceed, and with luck, this has given you some information to consider. Please do not hesitate to reach out... remember that we are experts when it comes to standalone EMS planning, installation, configuration, wiring, performance calibration, and trackside support!

For new customers here is what you need to know:

  1. Cobb AccessTuner will still be available (without FlexFuel) for 50-state road legal vehicles as well as competition vehicles. E85 tunes can be done with separate maps and E content sensors (early customers you guys remember when I sent you home with 10 separate maps that you could switch in realtime using the AP?).

  2. EcuTek will be available for competition vehicles needing the extended functionality of the factory ECU (FlexFuel, Launch Control, Flat Shift, Auto Blip, Map Switching, etc)

  3. Standalone EMS will be recommended for highly modified competition vehicles. All of the above features plus CANbus integration with OEM systems (2008+) and the richest feature set by far. I go into detail on my site about this option because it is the most misunderstood, and also the best.

For existing customers here is what you need to know:

  1. Existing Cobb AP calibrations written prior to the software update will retain full functionality. However, these calibrations cannot be adjusted or modified without losing the newly-eliminated functions. They are effectively frozen in time.

  2. We have migration paths to move you from Cobb AP into EcuTek or standalone at a price discount.



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