Performance Design XS Intake Manifold for Gen 4 LS3 engines

Take it All in

The XS Intake Manifold breaks the mold of the existing intake manifold architecture to maximize available space under the hood. When designing the optimum intake runner length and shape the fuel rail gets in the way…so Performance Design moved it: inside the intake manifold! After testing all the mainstream manifolds available, this manifold has done what no other did; make horsepower and torque gains on a stock engine with gains increasing as the engine got more aggressive with cam and exhaust upgrades. All other manifolds lost on HP or Torque to make the gain on the other.

performance design intake manifold

This move presents several engineering challenges we overcame. First, fuel must be delivered to the fuel rails. To do this, Performance Design engineered and manufactured a bespoke fuel rail for this product with a feed port in a precise location to interface with a custom fitting. This fitting passes through the intake manifold housing through a provision engineered into the upper shell gasket. A fuel crossover feeds the opposite bank. Next, injector electrical connectors need to find their way inside the intake manifold. They do this by using a short injector jumper harness which passes through a sealed grommet for each injector jumper. All custom molded seals are engineering to seal this innovative packaging strategy.

performance design intake manifold

The intake manifold runners were developed using CFD (Computational Fluid Dynamics) then several runner designs were tested on the engine dyno to validate the performance gains. The company ended with staggered runners with 3 lengths to optimize overall performance. Burst testing was conducted to ensure structural integrity beyond 6 bar (86psi). Performance Design will be releasing the first production pieces to several key partners to conduct further testing in various combinations.

The XS intake manifold fits all LS3-style cylinder head ports including L92, L99, L76, L77, LY6, LY2, L20, LMF, LC9, LH8, LH9, L9H and L94.

performance design intake manifold

Even with the additional features and components required for this unique design, Performance Design is able to offer this intake manifold at a price significantly less than existing products on the market.

Specifications & Features

• Injection molded glass reinforced nylon construction
• Modular runners with 3 staggered lengths for best performance
• Billet fuel rails with external quick disconnect near stock location
• Accepts standard EV6 LS3/LS7-style injectors
• Injector extension wires passed through sealed grommets
• 90-103mm or 112mm forward facing throttle body flange
• Carbon fiber center bolt cover
• Factory MAP sensor location
• PCV and Canister Purge Solenoid OEM connections
• Includes stainless steel hardware for installation
• Includes molded port, plenum and throttle seals
• Intake can be reversed on the engine


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Performance Design LLC





(248) 507-4885


2840 Auburn Court

Auburn Hills, MI 48326

ABOUT Performance Design LLC®

Performance Design was born out of a passion for product design and development to serve companies who don’t have the in-house capacity or expertise.  Along the way we began to design, develop and manufacture our own line of performance products for racers and enthusiasts.