With this release we are extremely excited to announce the next step in our revised “NexGen” Power Packages and accompanying Off The Shelf Maps for the Subaru platform, NexGen Stage 2 Power Packages for the USDM 2015-2021 Subaru WRX STI. In our never ending strive to provide additional upgrade options for owners of these vehicles, the Subaru Experts here at COBB took to our dyno to define our emissions compliant, NexGen Stage 2 Power Package utilizing products from our catalog that have an existing CARB Executive Order (EO) or have a known path towards obtaining one. What came as a result of extensive testing on the dyno, street, and even several trips to our local track are NexGen Power Packages which provide impressive power gains over the existing Stage 1 level.
These NexGen Power Packages and OTS Maps are currently emissions compliant in all 50 states and have a CARB EO issued. At this time, Stage 2 NexGen OTS Maps are available to download off the website and are also included in current Firmware on the Accessport (AP3-SUB-004).
NexGen Stage 2 Power Packages
These NexGen Stage 2 Power Packages for the VA STI are offered in three flavors with the only difference being the included intake system. The first supports all applicable model years and includes our Redline Carbon Fiber Intake while the other two include our SF Intake/Airbox combo that supports either 2015-2018 STIs or 2019-2021 STIs. Beyond those differences, the remainder of the packages are identical and aim to both maximize the efficiency of the intake system and provide enough fuel to take full advantage of of that increased airflow. A new set of Subaru OE Spark Plugs is also included.
Looking for a NexGen Power Package for your car? Click Here for all of our NexGen Parts.
The question we’re all curious about is how much power can these packages produce while retaining the factory downpipe and catalytic converters. We’re happy to say that these packages and their accompanying Off The Shelf Maps are able to provide significant gains over stock and Stage 1. For 2019-2021 STIs using 93 octane fuel, we see Maximum Gains of +21% TQ and +21% HP over stock. Peak gains bring a 6% increase in HP and 19% increase in TQ over stock. 2015-2018 STIs on 93 octane fuel enjoy Maximum Gains of +26% TQ and +26% HP over stock while peak gains come in at +8% HP and +17% TQ over stock.
NexGen Stage 2 vs Previous Stage 2
Not surprisingly , the NexGen packages produce the same low end torque gains and actually make more power up top than the outgoing Stage 2 configuration. This is, of course, due to the additional fuel available with the upgraded pump, rails, lines, and injectors. If you recall, our initial development of tuning support for the 2015 WRX STI immediately called out the factory fuel system as being a weak link that would need to be addressed in our Power Packages. In the graph below you can see where Injector Duty Cycle rose well beyond the preferred limit of 95%. With the fuel system upgrades we are able to safely make more power up top.