WEAPON-X SPI Kit: Secondary Port Injection [Camaro, Corvette, CTS V, LT1 LT4]

Vendor: WEAPON-X Motorsports


$6,299.00 $6,999.00
WEAPON-X Secondary Port Injection KitThe solution for big power needs is our secondary port injection and this is the same type of kit that GM opted to go with on...
Car Model
Manifold Port Modification

WEAPON-X Secondary Port Injection Kit
The solution for big power needs is our secondary port injection and this is the same type of kit that GM opted to go with on the 2019 C7 ZR1 as well as many other high performance DI cars. We have come up with the complete solution for your high powered LT car. Our secondary port injection kit has it's own low side solution with a large pump to get fuel from the tank to the engine. This pump ties into the OEM fuel line as well as running up to supply it's own system. It is fully regulated and has a return, essentially transforming your stock fuel system into a high power capable system. Once the fuel reaches the engine, it ties into our custom billet fuel rails that tuck nicely against the supercharger/manifold, and what is needed fires through the 1000cc injectors and then the fuel returns back to the tank. The system is easily controlled with a proprietary piggy back controller with it's own software and we offer a base tune file and full support. Installation is made easy with our complete plug and play wiring harness! 

WEAPON-X SPI Kit Features:

  • Secondary Control Module with:
    - Closed Loop Dual Wideband 02 Fueling 
    - Auto Learn Tuning
    - Boost Control Capabilities
    - Tach Outputs
    - Programmable Custom Outputs
  • Plug and Play Harness for your vehicle
  • Billet tank tap with 360lph Fuel Pump, lines, fittings, etc
  • Flex Fuel Sensor
  • Fuel Regulator for return
  • Fuel Rail Kit for your specific application with rails for Magnuson / Whipple / Procharger / LT4 Eaton blower,
  • Vehicle specific custom premade lines, fittings, etc for easy out of the box install
  • FIC 1000cc Fuel Injectors
  • Optional supercharger manifold port injector bung modification

We are also pleased to announce that we are now offering port injection bung modifications to your existing Procharger manifolds! These options are listed under the SPI kit or you can contact us directly to have your blower/manifold modified at sales@weapon-x.com

Supported Manifold Options:

  • LT4 Supercharger, Magnuson 2300, or Magnuson 2650,(no supercharger modification needed)
  • Edelbrock 2650 - requires some modification including cradle spacers on all cars and some minor inner hood modification on the Camaros and C7 as well as our included billet valve covers to clear the fuel rails
  • Whipple Supercharger (requires port injection modification)
  • MSD Intake Manifold (requires opening port injection bungs and MSD fuel rail kit)
  • Procharger Intake Manifold (may require port injection modification)
  • Other manifolds with typical port locations like: Holley, LME, Frankenstein, G1Pro, MSD, etc (requires their fuel rail kit)

Models Supported:

  • Camaro gen 6 SS, 1LE, ZL1, ZL1 1LE - LT1 LT4
  • Corvette C7 Stingray, Grand Sport, Z06 - LT1 LT4
  • CTS V gen 3 - LT4
  • GM Trucks are up next!

We have been working closely with some of the supercharger manufacturers to provide a complete fuel solution for all manifold options as well as model platforms and we're pleased to announce after months of testing, we're ready to release the WEAPON-X Secondary Port Injection Kit or abbreviated as WEAPON-X SPI Kit (pronounced SPY)! This complete package sets a new unprecedented secondary fuel solution from fuel tank to injector tips, allowing the end user to hit 1,000+ wheel HP with just a few basic mods on LT4 cars and this kit can support up to 1,500 wheel HP! So, the days of having to spend a lot of money on:

  • Larger High Pressure Fuel Pump ($2,000 installed)
  • Larger DI Injectors ($4,000 installed)
  • Low Side Fuel Kit ($1,500  installed)
  • Meth Injection Kits ($1,500 installed)
  • Heads/Cam Kits ($6,000 installed)

or combinations of the aforementioned exceeding $10,000 to barely hit 800+ HP are OVER! Now basic is relative of course, but with our modified Whipple or Procharger F1 kit, headers, head studs, WEAPON-X SPI port injection kit, you can see 4 digit power. So, for those guys shooting for reliable big power, this kit is unparalleled, plus we offer full support with installation and can provide a base file to start with, or even setup to remote tune your car. 

What is Port Injection?
Let's start off with the basics; port injection is the way engines were fueled since the 80s with an electronic ignition based fuel supply. The fuel injector is located in the intake manifold or on a positive displacement supercharger. When the signal is supplied, the injector opens and the amount of fuel sprayed depends on a plethora of parameters (ultimately by the gen IV LS engines), but to dumb it down, the milliseconds the injector is open, the size of the injector in lbs/hr or cc's, and the fuel line pressure supplying fuel to the injector from the tank to the fuel rails. The fuel sprays through the ports in the cylinder head and travels with the air entering the engine and travels through the valves into the cylinder where it is ignited and you have your robust combustion. It was always relatively easy to make big power numbers then, larger pump to supply the fuel to the engine and larger injectors to spray that fuel into the ports was about all it took as long as you had the capabilities to program the added fuel.

What is Direct Injection?
As technology evolved and emissions regulations became more and more stringent, direct injection hit the automotive world stage. Direct injection is very similar to port injection until the fuel supply reaches the engine, then it goes through a second "high pressure" fuel pump, driven off of the camshaft, which increases the fuel pressure from 70 PSI to nearly 3,000 PSI! It then goes through the high pressure injectors and enters the engine directly into the cylinder. This is great for a lot of reasons including more precise fueling, higher air fuel ratio ability when boosted, and of course emissions; however, the inherent problem that quickly arose was the limitations of fuel supplied. 
The lack of pumps and injectors capable of reaching those pressures made it extremely difficult to achieve big power numbers safely or running ethanol based fuels which are very inexpensive higher octane fuel right out of the pump. For a more in-depth explanation of how the GDI system works, checkout my other thread discussing this in much greater detail:
Guide to fueling for higher horsepower LT4 ZL1s

The Solution: WEAPON-X Secondary Port Injection Kit!
The best part about our kit aside from it being plug and play, is the fact that the ENTIRE KIT is complete under $7,000! This might sound like a big investment if you're just looking at the number, but this is a complete fuel solution from tank to injector tip including the secondary controller and tuning software as well as support.  Not everyone needs port injection for moderate power of course and we use all of the other options on customer builds as well, but for big power gains/goals, the WEAPON-X SPI Kit is a great bang for the buck and allows for future growth.

* Kits are custom made to your specified needs, so lead time can be 30-45 days depending on inventory quantities.  

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