Composite Performance Technologies LLC, used rapid-molded parts to improve the intake manifold's design then went directly to production tooling. The manifold's three parts are made from a high-performance PPA.
Composite Performance Technologies LLC, used rapid-molded parts to improve the intake manifold's design then went directly to production tooling. The manifold's three parts are made from a high-performance PPA.

Gearheads can now get a 20 hp performance boost over stock GM LSI/LS6 engines with the first composite aftermarket manifold from Fuel-Air-Spark Technologies, Ashland, Miss. The LSX intake is injection molded from a polyphthlate (PPA) composite that is 20% stronger than nylon 6 and significantly stronger than the nylon 6/6 it replaces.

It's also 25% stiffer and less than half the weight of an aluminum version. The aftermarket manifolds reportedly will let Corvette, Camaro, and Firebird aficionados boost V8 horsepower to 380 while increasing engine torque by 15 lb-ft.

The Amodel A-6135 HSL PPA from Solvay Advanced Polymers LLC, Alpharetta, Ga., also provides better heat advantage over aluminum. As an engine heats to its operating temperature metal manifolds act as a heat sink, preheating the cylinder's intake air. This robs horsepower from the engine.

In contrast, Amodel PPA acts as an insulator, letting much cooler, denser air enter the cylinders. The result is a lighter, stronger, stiffer manifold with built in horsepower gains thanks to the material alone. The PPA is also more creep resistant than nylon so it will help thwart air leaks at the manifold/gasket interface.

The intake's three-piece construction gives hot rodders access to every inch of the manifold. The middle and upper shells can be modified letting enthusiasts customize engines with additional upgrades such as a 90-mm throttle body. Special bosses are designed into the LSX to accommodate turbo or superchargers. Burst panels attached to the bosses help prevent engine damage from nitrous backfires.

To make the LSX a true bolt-on product, Managed Programs LLC, Rochester Hills, Mich., designed it to fit under a stock hood using factory hardware, fuel lines, and linkages. The firm also redesigned the runners so air moves more efficiently increasing both airflow velocity and volume. The LSX's longer, tapered runners reportedly let it gain top end horsepower without sacrificing low-end torque needed for better drivability.