Airflow engineers at RHS® and the EFI specialists at FAST™ recently worked hand-in-hand to develop a superior intake manifold for GM LS performance applications. With models available for all the popular LS engines, the LSXR™ features a three-piece modular construction to allow for easy disassembly and porting. Extensive testing led to a runner design that was longer and less restrictive, allowing the removal of individual runners for modification. Regardless of the application, dyno testing has proven these manifolds deliver significant bolt-on performance gains in stock applications and gains upwards of 25+ horsepower in larger displacement or highly modified combinations.

Constructed from advanced polymer material, the LSXR™ is lighter, stronger and more heat resistant than comparable aluminum intakes. While it features a 102mm air inlet, it can be used with 90mm or 92mm throttle bodies. Other features include integrated nitrous bungs and perfect bolt-on fitment, allowing use of factory accessories without clearance issues.

Designed specifically for GM 4.8/5.3/6.0L cathedral port truck engines and cathedral port LS1, -2, -6 race applications where hood clearance is not a concern, the FAST™ LSXRT™102mm Intake Manifold follows the path chartered by the original FAST™ LSX™ Gen III Intake by featuring a modular design that allows for easy porting and disassembly and a runner design that yields an incredible 25 peak horsepower gain over the stock intake, on a stock 6.0L engine with a Big Mouth 102mm Throttle Body™. And similar to the LSXR™ 102mm Intake Manifold for cars, the LSXRT™ features the ability to remove individual runners for modification.

The LSXRT™ is constructed from a proprietary precision injection molded polymer which offers many benefits, including lighter weight, greater strength and lower heat soak propensity. While it features a 102mm air inlet that was designed for the FAST™ Big Mouth 102mm Throttle Body™, it can also be used with stock 90mm or aftermarket 92mm throttle bodies (78mm three-bolt throttle bodies require an adapter). Other features include integrated nitrous bungs and precise bolt-on fit that permits the use of factory accessories and OEM fuel/emission connections without adjustments or clearance issues. Some GM truck models may require the FAST™ 92mm or 102mm throttle body.

When it comes to improving performance, increased airflow is a key ingredient. Available in 92mm or 102mm diameters, the Big Mouth Throttle Body™ increases airflow through a series of innovative design changes and slightly enlarged throttle opening. Significant testing and engineering was conducted to optimize cross-sectional flow and eliminate airflow turbulence, especially at part-throttle operation.

The throttle blade's increased thickness eliminates deflection, especially in boosted applications. To improve throttle response, the blade pivot is offset, while the beefed up linkage and dual throttle spring mechanism ensure total throttle control.