Diablosport Forums

Just ordered 3.91 gear from GM, (PN 19301504), and will have my local dealership handle the installation. I was told that they have to run a specific calibration for the gear to work properly after they finish installing. ("Calibration 12660300, 2011 & L99 Automatic Transmission applications. Note to Dealers: The calibration download and installation is to be charged to labor OP 0601058".)

Question: Concerning my 2011 Camaro SS/L99 6 Speed Automatic, will I need a custom tune after the install and new vehicle calibration, or will the "Canned Diablo 93 ECM Tune and the Canned Firm Shift Tunes" still be compatible and function properly; will changes have to be made to the tunes? Of course everything has been RESTORED and the licensing released...

Thanks.

the tunes will still work fine.. they don't change the gear ratio.. so after the dealer update, you can just install the preset tune and will be good to go.