The LS combos have the potential to make ground-pounding power, even in almost-stock trim. As usual, our bellies weren't yet full, though, and our minds were on the buzz for something more. We just knew our LS1 had more under its skin. Last month we left you with a stout LS1 package ("Magnificent," Jan. '09) that consisted of an LS1 with built internals, including the factory forged crank, a set of Probe 4340 lightweight I-beam rods, and lower-compression SRS series pistons. We topped it off with a set of Trick Flow's GenX Street/Strip CNC-ported lungs for deep breathing. For bump, we used Comp Cams' 230/236 hydraulic roller cam with 0.591/0.601-inch intake/exhaust on a 115-degree lobe separation.
But when you up the ante with MagnaCharger's latest and greatest supercharger system, it's a whole new ball game. It's critical that everything works in harmony and that air moves as freely as possible. The more air the better, and the longer that valve stays open, letting as much steam in as possible, the greater the ability to make power. During the last go-around, our supercharged LS1 produced a solid 652 hp and 579 lb-ft at a hair over 8 pounds of boost. Impressive? Of course, but we knew there was more to be had.
For the latest round of testing, we were all curious to see what would happen if a new camshaft choice was the only deviation from the last dyno session. Our 'stick for this test is a bit more radical and specifically designed for our positive-displacement MagnaCharger, featuring an additional 8 degrees of duration on the intake side and 10 degrees on the exhaust. Specifically, the new hydraulic roller from Comp came in at 238/246 intake/exhaust duration at 0.050 on a 114 lobe separation, with 0.605/0.613-inch intake/exhaust lift. We can undoubtedly say that we're pleased with the outcome. We still want to hear your thoughts, so tag along as we throw the Gen III powerplant back on the dyno and run it through its paces.
What We Did
Determined whether or not a blower specific camshaft makes a difference.
The gains are significant, but read on for the details.
To get the swap underway,...
To get the swap underway, Ernie Mena loosened and removed the tensioner, releasing the 10-rib belt. This kit uses one full serpentine system to spin all the accessories, including the supercharger's drive pulley. Mena then removed the water pump to gain access to the front of the motor.
Using a pen, we marked the...
Using a pen, we marked the pulley before we took it off, allowing us to find the exact location of the balancer when we needed to reinstall it after the cam swap.
What was helping all that...
What was helping all that heavy breathing? First, our Trick Flow 215 CNC heads are capable of moving up to 320/259 intake/exhaust cfm at 0.600 inch lift. We also had some serious help from Comp by using the company's Ultra-Gold 1.72:1-ratio roller rockers and matching 7 1/2-inch-long, 5/16-inch Hi-Tech pushrods with 0.080-inch wall thickness. Mena first removed the rockers to allow us to remove the camshaft.
We then removed the balancer...
We then removed the balancer to gain access to the timing cover. Removing the timing cover is a piece of cake and requires almost no effort. Using a 10mm socket, we loosened the bolts and took the cover off.
With the cover removed, we...
With the cover removed, we installed the factory crank bolt and spun the motor over until the timing marks lined up on the cam and crank gears. This ensured that the motor was at TDC, and we knew exactly where to put the gears once the new cam was nuzzled inside. We then removed the cam gear and pushed the chain to the side.
With a 10mm socket, we removed...
With a 10mm socket, we removed the outer bolts to the cam plate. Since the rockers were off, we could spin the cam freely. Using the special LS cam tool, we slid the rods into the center of the block through the oil galleys that feed the lifters. These rods on either side pushed each lifter up and away from the cam, freeing the cam and allowing us to pull it out.