Main changelog for v1.21:

Corrected bug that caused CTD on startup in some systems (no longer requires adding a DEP exception for GSC.exe)
Lots of optimization work to improve FPS / stuttering issues
F-Extreme physics reviewed to rectify a few errors
AI revised for improved behavior and minimizing difficulties with tighter corners
Multiple qualifying rules introduced in v1.20 have been temporarily removed to fix some errors - it will be added back in the next update.

Main changelog for v1.20:

Content

Cars:

-Added Stock Car V8 2014 season to Stock Car V8 series
-Added Formula Extreme series
-Added Formula Vee series
-Completed full Formula V12 field + updated graphics

Tracks:

-Buenos Aires (4 layouts)
-Spielberg (2 layouts)
-Spielberg Historic

Features & fixes:

-Added DRS functionality + rules (for F-Extreme / f-Reiza)
-Added multiple qualifying rules (F1 style / Stockv8)
-Added option to restrict prime / option tire compound selections per track
-Adjusted StockV8 tire change rules so only 1 tire is changed at a time as per real rules
-Revised tire physics on all cars in preparation to new tire model features currently in development
-Added multiple tire compound options with corresponding tirewall colors to F-Extreme / F-Reiza
-Adjusted dirty air physics for more realistic behavior
-Adjusted engine cooling properties in all cars
-Adjusted AI performance for wider range specially in lower strentgh settings, and more consistency all around from track to track, series to series
-Fixed bug with AI performance discrepancy from quali to race (RaceQualRatio=XX parameter now works in AIW files, lower than 1.0 value will result in slower qual times relative to race, higher values will do the opposite. By default AI should be about 2% faster in quali; remains an issue with AI being too quick in practice sessions)
-Increased rearview mirror resolution for all cars
-Corrected FOV / POV + tv cameras to the same standards for all cars
-Updated rumble sounds to be more "bassy" on all cars (for Buttkicker and other similar systems)
-Adjusted trackside cameras in all tracks for more realistic framing / tracking
-Adjusted some inconsistent road & terrain properties, fixing some overdone high frequency bumps
-Various environmental / lightining enhancements (new skies / fog and other updated shaders);
-Introduced new Foliage shader which looks better & is more optimized to provide performance boost
-Added 3d tyre lods at Granja Viana to help ease performance issues
-Added 3d Armco at Interlagos

Known issues:

-The F-Extreme ERS system has been simplified for this release - basically, the battery is fully charged all the time and the power blending still needs work, meaning the driveability under throttle is not quite what it should be yet;

-The AI for the F-Extreme does not use 8th gear or DRS;

-The hard compound for the F-Extreme & F-Reiza does ot have its proper grey Pirelli sidewall label.

IMPORTANT: Mods that have loose files that conflict with original game files will cause trouble - make sure your "Shared" folder in particular is clean before you update. For the same reason mods & addon tracks might require some updating in order to work properly.

Full v1.20 installers will come shortly. In the meantime if you don´t have the game yet, head to www.game-stockcar.com.br, download the full v1.15 installer and update to v1.20 with GSC Sync or one of the update packages below.

If you already have GSC2013 v1.15 installed, you may update to version 1.20 by running GSC Sync from your root GSC2013 folder.

Alternatively, download the update packages below (2.3GB in size) and unrar the contents into your GSC2013 folder, overwriting files when prompted: