LS Engine Performance Packages - Staging A Comeback

Today, it's all about the total package. You wouldn't order your eggs without salt, pepper, and assorted Tabasco sauces, right? Nor can you be a successful football quarterback without the right playbook and talented linemen to protect you. The same goes for your high-tech LS engine, and deriving the best power, reliability, and drivability requires a well-designed combination of parts.

To achieve the best bang for the buck, you need to select parts that work together as a team. And when you start with a sophisticated piece of engineering such as your Corvette's LS engine, unless you have a performance plan, you could be in for big trouble.

Recognizing this, Comp Cams and the Comp Performance Group Companies set out to build a series of power-improving packages that fit both the performance and budgetary requirements of today's LS-engine (LS1, LS2, and LS6) owners. For those of us who can never have enough horsepower or torque, this five-stage program makes it possible to add a little or a lot of both.

As noted, the Comp LS upgrades fall into five stages, each featuring a group of power-matched components. These part combinations were selected through countless hours of dyno testing, tuning, and retesting at Comp's headquarters in Memphis. The results are documented through the SuperFlow dyno charts supplied with this story.

For this installment, we decided to include the first four upgrade stages, holding the more involved Racing Head Service (RHS) cylinder-head swap for next time. Note that each stage builds on the last. In other words, you can't skip over stages to increase horsepower, as each new stage requires the installation of the previous level.

All of our tests were performed on a factory-fresh LS1 engine that generated 375 hp and 370 lb-ft of torque in Comp's baseline dyno tests.

Stage I
There are plenty of urban legends about the power of handheld programmers. The fact is a properly engineered unit can do great things to improve the power, fuel efficiency, and drivability of your vehicle. The FAST-FLASH Power Programmer is arguably one of the easiest-to-use programmers on the market. You simply plug it into the diagnostic port under your Corvette's dashboard, read the text in the viewing screen, and answer a series of questions by pressing the buttons on the face of the programmer. Like most handheld programmers, the FAST-FLASH unit "remembers" your ECM's original settings, so you can revert to this baseline point whenever you desire.

To optimize the programmer's potential, Comp engineers decided to address what is perhaps the LS-series engines' most serious inherent deficiency. Simply stated, the factory-supplied LS1 pushrods are weak-so weak that in early Spintron testing, both camshaft lift and duration were compromised by pushrod flex. The fix: a set of 0.080-inch-wall, 51/416-inch-diameter, 7.400-inch-long Hi-Tech pushrods. These pushrods fit in the stock location and don't require any cylinder-head modifications.

The final change was to add a set of ZEX performance spark plugs. These plugs feature a heat range designed to deliver increased performance, long life, and excellent fouling resistance in a street-based LS engine.

With our new parts installed and the FAST-FLASH Power Programmer hooked up, a number of dyno pulls were completed. By programming the FAST-FLASH to Power Tune Setting No. 2 and leaning out the mixture slightly with a "Minus 5" fuel/air configuration, we unlocked 11 additional horsepower and 12 more lb-ft of torque.