Having owned 5 3800 powered vehicles and professionally tuning 3800s for 14 years, it's with great pride that Overkill is a premier 3800 tuning service. Improving performance and drivability, maintaining a healther transmission and improving fuel economy wherever possible are all high priority for Overkill 3800 tuning. It's with confidence that we know you'll enjoy Overkill tune above all others and your Overkill tune will help you enjoy your vehicle more than before.

Features and Benefits:
  • Each Overkill 3800 tune is Made-To-Order based on your vehicle, with no extra charges for customization no matter what
  • Improved Performance on either 87 or 91/93 octane - Smoother quicker acceleration, sharp throttle response, reduced KR, typical gains of 10+ wheel horsepower with normal bolt-on mods
  • Improved Transmission Performance and Life Expectancy - Includes skip shift enabling, quicker shifting, lowers fluid temperatures
  • Removes P0128 code for 180* thermostats, P0420 code for high flow cat converter, codes for EGR, EVAP and rear O2 sensor upon request
  • Key Security disabling available for no-start issues relating to aging ignition switches (common 00-05 Impala problem)
  • Tuning available for gear ratio swaps to or from 3.29, 3.05 and 2.86 differential ratios (great for retrofitting a used transmission with a different ratio)
  • Many small features such as speed limiter removal, A/C compressor shut off under heavy throttle to regain horsepower, revised cooling fans with key off fan on enable, reduced traction control intervention and more
What makes Overkill tuning better than the rest? Attention to detail, amount of features, continuous improvement. We do what many others can't and don't, here are some examples:
  • Transmission Shifting - You'll love how the transmission behaviour is fully recalibrated in an Overkill tune and improves how the vehicle drives
  • Torque Management - While others zero out a common lookup table or disable a master switch to fully remove, we reprogram torque management to remove power limiters but still allow engine depowering during transmission upshifts, critical to transmission life expectancy
  • 2006+ Tuning - We were the first to offer 2006-2007 Grand Prix tuning, still the only ones to offer 2007 tuning where the fuel gauge doesn't work in reverse, and still the only ones to offer a core exchange and deposit refund on 06-07 modules
  • Correct Gear Ratio Programming - More correctly programs aftermarket gear ratios versus the HP Tuners method
  • Corrects common observed fuel trim issues which vary year to year including high negative 04+ Grand Prix trims

87 vs 91+ octane The 3800 V6 engine is modestly suceptible to engine knock/ping/preignition when compared to its peers. If you're purchasing a tune and looking for the most horsepower, we can do the most for you if you're willing to run 91+ octane. If you're purchasing for a noticeable performance increase during daily driving, improved transmission life and behaviour, and fuel economy, the 87 octane tune will provide the benefits you're looking for. With breathing modifications such as exhaust work including downpipe, an intake system and ZZP HV3/rockers, 91+ octane benefits are available with 87 octane.