Map Notes for 2019 - 2021 STI, 2018 STI Type RA, S209

Supported Vehicles:

  • STI USDM 2019-2021

  • STI Type RA 2018

  • STI ADM STI 2019

  • North American 2019 STI S209

*To confirm your model year, you can refer to the tenth value in the VIN number on the vehicle. For model year 2001-2009, the 10th value in the VIN will be the last digit of the model year. For model year 2010-2019, the 10th value in the VIN will be A-K, starting with 2010, ending with 2019.

Current Map Revision:

North American 2018 STI Type RA, 2019-2021 STI

North American 2019 STI S209

ADM 2018-2019 STI

North American 2018 STI Type RA, 2019-2021 STI

North American 2019 STI S209

ADM 2018-2019 STI

  • Stage1 v400 Boost Select

  • Stage1+SF v400 Boost Select

  • NexGen Stage2 1050x v504

  • NexGen Stage2 1050x + Flex Fuel v510

  • Stage1 v400 Boost Select

  • Stage1 v346 Boost Select

  • Stage1+SF v346 Boost Select

  • Stage2 v346 Boost Select

Accessport Firmware: 

  • AP3-SUB-004: or greater

  • AP3-AU-SUB-004: or greater

Fuel Requirements:Each map lists the minimum required octane. A higher octane fuel can be used safely on a map designed for lower octane. DO NOT use maps designed for higher octane with lower octane fuels. Top Tier gasoline should be used where available.

  • Maps designated with "93" are for use with 93 and 94 octane/98 RON fuel or better.

  • Maps designated with "91" are for use with 91 and 92 octane/95 RON fuel or better.

  • Maps designated with "ACN91" are for use with 91 octane fuel found in Arizona, California, and Nevada or better. And additionally for those in Canada, for use with 94 octane Fuel at a minimum.

  • Maps designated with an octane (ACN91, 91, 93) and FlexFuel are good for the labelled fuel octane, E85 and any blend in-between.

2018 WRX STI Type RA  (North American spec)
2019-2021 WRX STI (North American spec)


Flex Fuel Gains

Hard Part Requirements for Maps



  • HWG: Higher wastegate duty cycles (HWG) for use when normal wastegate calibration produces lower than targeted boost (i.e. under boost). 

  • LWG: Lower wastegate duty cycles (LWG) for use when normal wastegate calibration produces higher than targeted boost (i.e. over boost).  

2019 STI S209 Stage 1

Stage 1

  • Intake Requirements: Stock airbox with stock air filter

  • Exhaust Requirements: Stock exhaust or upgraded cat-back exhaust

  • Boost Targets:

    • 93 octane (98 RON) Minimum: ~22psi [S#] tapering down as you approach the 7000RPM redline, +/- 1.5psi.

The COBB OTS Map availability for the S209 is a bit different than our typical WRX or STI assortment. With a limited number of cars available to be used for testing, and based on our findings, the only performance map offered at this time is a Stage 1 OTS map for 93 octane fuel. During investigation and development of this map, our calibration team noted that even utilizing the factory calibration with 93 octane fuel, the S209 exhibited an inconsistent and undesirable amount of knock.

For more information on the s209 release check out our blog post

Non-Performance Maps


Anti-Theft Mode

  • Will not allow vehicle to start


Economy Mode, Intake+Economy Mode

  • Boost Targets: Typically around 6psi - 12psi

  • Rev Limiter: 5800 RPM


Valet Mode, Intake Valet Mode

  • Boost Targets: Typically around 6psi - 12psi

  • Rev Limiter: 3200-3800 RPM

Monitoring Boost Levels: 

The best way to determine if you are hitting target boost is to watch the TD Boost Error parameter. This parameter is your target boost (including altitude and temperature compensations) minus your actual boost (negative values mean you are over the target by the amount while positive values mean you are under). Ideally you want this value to be between 0 and 1.0 at wide open throttle (WOT), but -1.0 to 1.0 is acceptable assuming that you don't have any significant knock corrections. Overboosting is more likely to occur in higher gears and with colder outside temperatures, so be sure to verify boost levels during these conditions. 

High Altitude: 

A quick note for those of you that live at higher altitudes: it is common for turbocharged cars at higher altitudes to run less boost pressure due to lower air pressure and air density. Your turbocharger has to work harder to compress a less dense air mass compared to the same turbocharger at sea level. This must be factored in when determining if your turbocharger is running the proper amount of boost pressure and not being pushed beyond its efficiency range. 

Example: If you live in Denver at 5280 ft and are trying to run a peak boost pressure of 15 psi, your turbocharger has to work the equivalent of making ~17.5 psi at sea level.

There are barometric compensations within the factory ECU that lower boost targets as you climb in altitude in an effort to keep the turbocharger in its optimal range. The COBB performance maps utilize these compensations and therefore, it is perfectly normal for the final boost target to be lower than what is listed for your map. 

Boost Select: 

All maps designated with "Boost Select" in the map name have a driver-controlled boost target controlled through the SI-Drive system available on the 2008+ STI. From the factory, SI-Drive will modify throttle settings and change the relation between what is done with the accelerator pedal and how the throttle blade reacts; [S#] being the most aggressive throttle settings, [S] being less aggressive, and [I] being very conservative. What we have done is take that functionality a step further. The "Boost Select" maps have selectable boost targets enabled by toggling between [S#], [S], and [I]. [S#] will target the highest boost level, [S] will be a medium boost level, and [I] will be the lowest boost level (wastegate spring pressure). You can find the specific boost targets for [S#], [S], and [I] in the Map Version Notes above. 


Revision Notes: 

Version #


Version #



maps updated to remove unnecessary dtc suppression or for version parity with other maps.


19 STI S209 Boost control improvement under 40 degrees F only. No other changes.


18 RA, 19 STI North American spec Stage1+  maps receive small tweak to very cold weather boost target. Initial release of 2020 STI North American spec support.


18 RA, 19 STI North American spec Stage1+ map long descriptions updated. No change to calibration. 18 RA, 19 STI North American spec Stage3 1050x Valet map even further torque reduction in Sport and Sport# modes.


Revised IAT based ignition comp., boost compensations for baro., per gear, intake temp., coolant temp., revised 18 STI RA/19 STI North American spec engine calibrations.


Minor visual updates on North American spec MY18 STI Type RA Stage1 maps. Boost Limits table update on ADM 2018 Stage1+SF 93 map only.


Adjusted MAF calibration on North American spec MY18 STI ACN91 Stage1+SF maps only. v345 for North American spec MY 18 STI ACN91 Stage1+SF was only available for a few hours, but if you have it, please use v346 or newer instead.


Updated boost target, limit tables to account for MY2018 OEM strategy change.


Added Stage3 mapping. Revised throttle mapping for all maps to improve driver's ability to modulate vehicle speed at light throttle positions. 


NASIOC-only beta test with improved air-fuel ratio control at higher RPM on Stage1, Stage1+SF mapping. 


Original Mapping. Adjusted Fuel, Ignition, Boost Control, Camshaft Phasing (AVCS), Closed Loop to Open Loop Transition, Per-Cylinder and Per-Gear Timing Strategy, Intake Air Temperature Compensations, Barometric Compensations, and Engine Load Compensations. Added Boost Select (see above for description), Speed Density, Launch Control, and Flat-foot Shifting capabilities.

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