\ :: Overkill Motorsports ::




Overkill's own personal 2013 ATS 3.6 pictured above, trust the 3.6 guru that owns the same vehicle you do!













Overkill is proudly a premier tuner for the GM 3.6 V6 family of engines. I not only tune and modify but I've personally owned several 3.6s including the black ATS you see above, and I love that GM packed this light little car with a healthy V6 powerplant to make it quick and fun to drive. With specialized 3.6 products available from Overkill, choose the tuning that will support them, from E85 to larger throttle bodies to forced induction! Even if you do nothing except the tuning, you'll appreciate the Overkill improvement to how your ATS performs and drives.

What you'll notice:
  • You'll receive our Overkill 87, 91 and 93 octane tunes, with Overkill E85 Ethanol tuning if flex fuel enabled
  • Horsepower gains of 15-22 horsepower at the wheels depending on modifications, 30+ for E85
  • Smoother power delivery, harder acceleration from launch
  • Improved transmission shift patterns in touring and sport mode, firmer WOT shifts
  • Tuning support for your other aftermarket modifications including intake, exhaust, our 3.5" MAF and 80mm throttle body
  • Custom tuning revisions when you send driving scans and complimentary updates for future modifications

What youíll get:
  • Your choice of tune delivery handheld or tuning suite
  • Overkill tunes for 87 octane, 91 and 93/94 octane.
  • Tuning revisions when you send in driving scans, so the tune can be tailored for your vehicle

Technically speaking, the changes are significant. A full rework of the timing tables from 1400rpm on up at all throttle positions for several different gasoline octanes, revised performance fuel targets, revised torque modeling (throttle control) in both touring and sport mode, revised variable valve timing positions, a full revision of the upshift/downshift shift patterns in both touring and sport modes, reduced torque management intervention, speed limiter removed, rev limiters raised. Significant areas of improvement are made to the tuning along with revisions for specific modifications such as MAF tables for aftermarket intakes, diagnostics for exhaust work, extensive revisions for forced induction such as supercharger or turbochargers.

Why get an Overkill tune versus the competition?
  • Specialized in the GM Direct Injection V6 motors. From revised cam phasing, fully reconstructing spark timing tables and fully revised throttle calibration, an Overkill tune is more comprehensive than what you'll get at your local dyno shop, or a do-all tuning provider.
  • Datalogging. You'll get your Overkill tunes but it doesn't stop there. You can scan with our handheld while driving and send that data for review and tune updates, to get a tune that's more customized for your vehicle
  • Support for your mods. Not only are we the only company with an E85 Flex Fuel conversion kit or a larger 80mm throttle body kit, but we also have the right tuning to ensure you get the most from them!
  • Retunes. With our handheld, retuning for your future modifications is complimentary and easy to provide




HP Tuners Ė HP Tuners works on all model years. It requires a windows based laptop computer or tablet with USB port to interface with the vehicle inside the vehicle. Youíll use the software to read the factory tuning and upload Overkill tuning, along with take driving scans. Overkill tuning can support all our modifications including the supercharger systems and including 2017+ transmission support through HP Tuners.

EFI Live Autocal Ė Autocal works on all model years. Youíll need a windows based personal computer with usb port to transfer files to and from the Autocal however the Autocal works autonomously within the vehicle so you donít need anything but the handheld to read or write tunes or do a driving scan. 2017+ owners can receive engine tunes through Autocal. Given that easier use in the vehicle and the lower pricepoint, itís a popular option.







Select Your Year
Any Performance Mods?








Select Your Year
Any Performance Mods?








If you have a 2013-2015 ATS and already have a Diablosport device for tuning, I can provide Overkill tuning for Diablosport. Overkill tune files are provided through email which can then be uploaded to your Diablo device and flashed into your ATS just like the Diablo preloaded tunes. Purchase price will include several Overkill tunes plus tune revisions based on your driving scans. Keep in mind that Overkill cannot tune for bigger modifications like camshafts, superchargers etc but for basic bolt on modifications, no problem through Diablosport's custom tuning suite! Once purchased, you'll need to pull off the "backup" and "last tune written" files off of your Diablosport device's drive and email them to willoverkill@gmail.com.

Tell Us Your Year
Tell Us Your Modifications






This kit fits 2014-2015 models which don't have flex fuel capability already!

Running E85 ethanol is worth a legitimate 10-15 horsepower gain over high octane gasoline. This flex fuel retrofit kit gives your ATS the ability to run either gasoline, E85 ethanol or any mixture of and the computer will self adjust. Overkill tuning, or custom tuning to turn on the sensor, is required. For some strange reason, GM had flex fuel on 2013 models but they discontinued E85 ethanol capability for 2014-15, so here's the Overkill retrofit kit which will add it back!

Select Your Engine








The only larger throttle body for the 2012+ 3.6 is developed at Overkill. The factory throttle body is 72mm; our 80mm throttle body solution dwarfs the stock unit and will allow the your engine to breathe, improving horsepower, improving throttle response (particularly with Overkill tuning) and changes the intake note of the V6 to a deeper growl at heavy throttle.

Uses brand new parts, comes with an aluminum adapter plate, stainless steel bolts and some parts to assist installation. Works best with tuning and when used with a ported intake manifold. Note: this throttle body has a 3.5" clamping area, compared to the factory throttle body of 3". Ensure you have a solution available before installing the throttle body, your current intake system tubing may not fit!

Optionally add a ported intake manifold. Our 2016+ LGX ported intake manifold enlarges the opening to 80mm to match the adapter plate, which becomes a permanent pairing; for this reason, only a brand new manifold is used and you do not need to send in your factory manifold! For 2013-15, we tap our good friends at JacFab for one of their epoxy filled and ported intake manifolds, based again off of a brand new GM manifold. Gains of 20-25 horsepower can be found. Manifolds are made to order, please allow roughly 2 weeks for these manifolds to be made .

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The Overkill Supercharger kit for the ATS is so awesome that it needs its own product page. Add 200 horsepower or more to the LFX or LGX 3.6 engine with a weekend bolt on solution. Follow this link http://www.getoverkilled.ca/atssupercharger.html or click on the pictures below to go to the ATS Supercharger page for full information




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