Welcome to the Overkill Superchargers Accessory page. This is where you’ll find additional components to upgrade your system, plus select replacement parts that may be needed several years down the line.

The Overkill water/methanol injection kit is specifically for the Overkill supercharger systems and your vehicle. Rather than using a universal kit and adapting it to fit with mixed reliability, this kit is easy to install, designed to be dependable and right sized components for the job.

Injecting water/methanol increases effective fuel octane and cools the incoming air charge, this reduces engine spark knock in both cases. You can use this kit to maximize your current setup's performance if you have a little spark knock, you can run a few more PSI of boost over the Stage kits, you can run Stage 2's 10psi on a Stage 1 kit without the fueling upgrades, you can suppliment a minor fuel supply shortage when running 12+ psi.

Main design features:
Assembled to order, allow roughly 1 week before shipping.


Your Vehicle?

Want to see what the installation is like? Click here for PDF installation instructions

An Overkill original and exclusive - Port Fuel Injection Manifold!

The Overkill Port Fuel Injection Manifold is designed for E85 ethanol use the Stage kits (above 10-11psi boost). The Stage 3 fuel upgrades can supply 10psi boost on full strength E85 ethanol, but we need more fuel supply to run 12-13psi or up to 14-15psi on full concentration E85 ethanol. This manifold injects extra fuel but bypasses the DI high pressure fuel injection system, using fuel tank fuel pump pressure like a traditional port fuel injection system. By passing the DI system, it can work together with it to supply extra fuel. The system is dormant under regular driving and activates under boost. Fuel is delivered through professionally constructed steel braided lines and relies only on a top quality wiring harness and fuel solenoid to activate.

This manifold replaces the LFX aluminum lower intake manifold. No permanent modifications are required to the vehicle or engine. Tuning is required. The Stage 2 in tank fuel pump upgrade is at minimum required to run this manifold. The LFX upper manifold can be either factory or ported upper LFX manifolds, it does not impact this choice.

Main design features:
  • Bolt in Replacement - replaces lower intake manifold but requires no modifications to upper intake manifold
  • Bypasses Direct Injection fuel system - supplements fuel flow under boost without requiring additional DI fuel system upgrades, doesn't increase fuel consumption at idle or cruise
  • Custom wiring harness - measured for each Camaro or Cadillac vehicle specifically, top quality components, OEM connections, no cut/splice required, no controllers to fail, boost activated
  • Simplicity - Kit doesn't rely on external pumps, boost activated fuel flow, no controllers to fail

  • Two manifolds are available sized to support around 12-13psi on full E85 or 14-15psi on full E85. The 12-13psi manifold is easier to tune and recommended for most people running on the street. If you have a built motor and/or are pushing the limits at 14-15psi, then consider stepping up to the larger nozzles. These are NOT interchangable once the manifold is built.

    Black Friday Pricing - $950

    Your Vehicle?
    Intended Boost Pressure

    High Pressure Fuel Pump Upgrade - 2012-2015 LFX engines

    This upgrade to the high pressure mechanical fuel pump (that attaches to the engine) allows for higher fuel pressures and increased fuel capacity. Part of the Stage 3 kits. A direct replacement and a short extra install time when doing the Stage 2 kit. Available only for 2012-15 LFX and 2010-13 3.0 LF1 engines at this time.

    2012-15 LFX Only!

    Larger Fuel Injectors - LLT/LFX/LGX Direct Injection engines

    You can purchase separately our larger fuel injectors for all the direct injection 3.6s. These injectors will come as direct swaps and will support more boost pressure than factory injectors. LLT fuel injectors rate around 135#, while LFX rate around 124# and LGX at around 126# (factory sizes are 105/109/96# respectively).

    Before it's asked, yes you can run the LLT fuel injectors on the LFX if you run an LLT fuel rail and modify the fuel injector wiring sub-harness. They won't fit the LGX.

    Select Your Engine

    Replacement Tensioner Assembly

    One eventual wear item on the kit is the belt tensioner. This is a replacement fully assembled belt tensioner. Put together with several custom components, it's better to sell you a full new assembly if you need it. Note for 2020 the new style tensioner body that will be more durable and provide better belt tensioner.

    Tensioner Assembly

    Replacement Catch Can Check Valves

    The absolute newest check valves used for our catch cans. Not cheap but too important to cheap out on, these are aluminum body and Made In USA, they're also designed specifically to be opened with vacuum suction and will withstand boost pressure from the intake manifold at full throttle.

    All come with 3/8" hose connections except 2016+ Camaro where one valve will come with one 1/4" hose connection.

    Check Valves