Chapter 2: Engine Dyno of the MAX Performance Package


Here is our latest testing of the LS3 / L99 MAX Performance Head & Cam Package.

We’ve taken the goodness of the LS7, and adapted it to the LS3 / L99 platforms, to create a package that is the best of both worlds! The MAX Performance Package is built with an LS7 Cylinder Head, which lets us run a smaller combustion chamber, with additional piston to valve clearance, and still run a lot of camshaft. This seems to be the perfect combination.

After many months of working in secret – we are proud to introduce the GPI MAX Performance Head & Cam Package for LS3 / L99 applications!

This package is not for the faint of heart. With a huge powerband, torque down low, and an explosive LS7 top end – this is a no compromise NA build.

This first test build made 542rwhp, and we’ve just started working on the next build #2!

Preorder your MAX Performance Package online NOW!

gpi max performance head & cam package

MAX Package Includes

  • GPI MAX Performance LS7 Cylinder Heads w/ BTR Titanium Springs
  • GPI MAX Performance Camshaft (choice of 2)
  • LS7 Intake Manifold
  • 1.8 Ratio Rocker Arms
  • Fuel Rails
  • All necessary gaskets, bolts, and seals for DIY’er

Video Preview

Designing the MAX Package

The restrictive factor we encounter when taking the LS3 / L99 beyond 500 rwhp is “piston to valve” clearance and intake manifold.  

The MAX Project resolves both issues. 

We designed a 12 degree cylinder head – which enables us to run more camshaft and less combustion chamber on these engines – without having to resort to fly cutting valve reliefs in the pistons – so we found the perfect compromise.

This head flows over 400 CFM intake and 270 exhaust featuring a 2.180 intake valve and a 1.59 exhaust.

The intake runner remains a reasonable size for a 376CID engine and allows us to solve the intake manifold issue by allowing the use of a LS7 style unit.

The Verdict

Here are the results of our test vehicle.

This was a 1LE car with 1-7/8″ long tube headers, air box, and a leading competitors Stage 3 camshaft package.

The graph shows the baseline of 453 rwhp, and 519rwhp on 93 pump gas…

…and 542rwhp with the MAX package on E-85.

What’s Next?

We have several builds in the works, and look forward to sharing them with you!

Order Now!

LS3 & L99

2 thoughts on “Chapter 2: Engine Dyno of the MAX Performance Package

    • gwatneyperformance
      gwatneyperformance says:

      The price does not include installation. It includes the cost of the GPI MAX Performance LS7 Cylinder Heads w/ BTR Titanium Springs, GPI MAX Performance Camshaft, LS7 Intake Manifold, 1.8 Ratio Rocker Arms, Fuel Rails, and all necessary gaskets, bolts, and seals for DIY’er.

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