Two Step Performance

Stage 1 to Stage One+ UPGRADE for the 2017+ Si (Existing Stage 1 Owners Only)


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  • $74.99
  • Regular price $149.99

Customer Reviews

Based on 41 reviews
Great Tune

Smooth, great midrange, great mpg when driving easy


Stage 1 to Stage One+ UPGRADE for the 2017+ Si (Existing Stage 1 Owners Only)


Great improvement. Car feels more alive than it did with the previous tune

Really Good Tune

I ran the TSP Stage 1 for 1-2 years (always on map 3/in sport mode 90% of the time) with no problems. Naturally, I had to give this a try and love how much smoother it is. Unfortunately at over 6,000 feet of altitude the factory turbo can’t throw more than 21psi so the original stage one actually felt a little quicker, but I’m sticking with the one plus anyway. Something to consider if you live at a higher altitude. Still 5 stars because the tune is great and TSP definitely isn’t at fault for the limitations of the factory turbo.


Stage 1 to Stage One+ UPGRADE for the 2017+ Si (Existing Stage 1 Owners Only)

Good tune

Tune pulls very hard and smooth , you really feel the push of the torque when you go full throttle.

Existing TSP Stage 1 Si tune owners can use this product listing to upgrade to our new Stage One+ tune at a discounted rate! This is eligible to anyone that has purchased the TSP Stage 1 tune directly from us, either as a standalone tune or with a KTuner unit. This will be verified before the order is filled.




Are you looking for the highest level of safe power output from your 2017+ Civic Si? Look no further!

Two Step Performance continues to partner with Derek Robinson to offer an even more powerful tune for the 2017+ Si. Full details are as follows:

234whp / 279tq - TSP Stage 1 Tune
248whp / 290tq - TSP Stage One+ Tune

All testing was completed on a stock 2020 Civic Si running 93 octane fuel. Tune features include:

  • Numerous fuel, ignition, turbo response, throttle response changes.
  • More aggressive tuning strategy compared to original TSP Stage 1, allowing for more midrange and top-end power.
  • Increased warm idle speed to eliminate vibration from aftermarket mounts.
  • Standard MAF, PRL Motorsports "Race MAF", and 27Won Performance "Race MAF" support (select appropriate option)
  • WOT shifting enabled. (Set to 5000RPM)
  • Adjustable launch control enabled.
  • "Rev hang" disabled with soft throttle padding (user adjustable)
  • Several tweaks to smooth the feel between gear shifts.
  • All disables / monitors are able to be adjusted by the end user.
  • Quick Boost By Gear is able to be adjusted by the end user.
  • On-the-fly boost map switching active for normal and "Sport" modes. (see below)
  • Throttle Responsiveness & Throttle Padding Settings are allowed to be adjusted by the end user so that the overall feel can be aggressive or more toned down, as desired. 

Map 1: Factory boost levels and turbocharger response.
Map 2: 19psi normal, 21psi "Sport" mode, Improved Turbocharger Response 
Map 3: 26psi normal & "Sport" mode, Fastest Turbocharger Response


Factory boost level in "Map 1" allows for easy "valet" mode when the KTuner unit is unplugged from the car!

93+ octane REQUIRED. Use of lower grade fuels is NOT tolerated, and will result in power loss.

  • 100oct race gasoline is suitable, as long as it does not contain lead.
  • The calibration will support up to about 15% ethanol content if necessary to increase knock resistance. For example, you can blend approximately 1 gallon of E85 with 91 octane to achieve the knock resistance required to safely and effectively use this tune.

Upgraded clutch recommended.

Suitable for use with the factory intake or a QUALITY aftermarket intake that keep fuel trims in check such as the PRL Motorsports Cobra. Aftermarket downpipes are also fine. Mods such as this are expected to add power that is not accounted for in our dyno testing.

In addition to standard sized intakes, the PRL Race MAF Cobra & Short Ram intakes as well as the 27Won Race MAF intake are supported. Please select the appropriate option for your intake when ordering. Need to make a change later down the road? Take advantage of our File Conversion Service.

*Tune orders placed during business hours are typically fulfilled via email the same day. Orders outside of business hours are filled the following business day. FlashPro tune orders may be slightly delayed due to the process required to build your custom file.*

Please verify that your ECU is supported via our TSP Tune Compatibility List prior to purchase.

This tune is for the 2017+ Civic Si only. Please be sure you are purchasing the correct tune for your vehicle because digitally delivered items are non-refundable. (If you buy this for your 2016 Civic LX, it won't work, and we cannot offer a refund.)

Click here for our installation guide.