You may notice that the camshaft appears to be somewhat conservative on duration, but our experience with high-flow cylinder heads like these TFS castings is that less duration is required to make the same power at higher engine speeds. This is mainly due to the more efficient cylinder heads that flow much more air, therefore allowing the engine (even with a shorter-duration cam) to push the peak horsepower rpm point a little higher in the power curve. The advantage to using a shorter-duration cam is that the lower and midrange power is better with a shorter cam, which means the car will accelerate better from a tight converter launch.
|'01-'03 OE LS1 cam, intake
|TFS Track Max, intake
|PN 30602003, exhaust
TFS offers a total of four different camshafts. We won't list them all, but the '03 cam we used is second from the longest in duration. The biggest cam, intended for the LS2 engines, pushes the envelope with 238/242 degrees at 0.050 and 0.595-inch lift. This might help with max power, but it will also push the peak horsepower close to 6,800 rpm, which will eventually hurt the cast-aluminum pistons. For the larger cam, a set of forged pistons is highly recommended.
The TFS Fast As Cast 220cc heads maintain great mixture velocity through the smaller intak
The TFS heads come with CNC-machined chambers displacing 65 cc with valve sizes of 2.055 a
After we loaded up the LS1 motor on Westech's dyno along with the dual-plane Edelbrock intake and the matching Edelbrock timing module, we were ready for our initial testing. But right off the mark, the engine sounded out of tune. After a little diagnostic work, Westech's Steve Brulé discovered a major vacuum leak at the intake gaskets. To solve our problem, we had to stack a pair of Fel-Pro gaskets. This situation is not uncommon because Fel-Pro makes three different gasket thicknesses (0.030, 0.045, 0.090 inch) to accommodate it.
Once we had the intake sealed properly, the motor pulled nicely through the powerband, making a peak of 414 hp at 6,400 rpm-much higher than the stock 5,200. We attribute this to the unrestricted intake and exhaust, since we were using a set of Kooks 13/4-inch stainless headers with 18-inch collector extensions and no mufflers. This might be further reinforced by the fact that peak torque did not alter from its factory 4,000-rpm set point, which actually makes the powerband between peak torque and peak horsepower an amazingly wide 2,400 rpm. Once we had the baseline set, we pounced on the poor LS1, and in about an hour, we swapped the heads, changed cams, and had everything buttoned back up and ready to run.
The baseline configuration consisted of the stock LS1 enhanced with an Edelbrock dual-plan
The beauty of this kit is that TFS has done its valvetrain homework. The Harland Sharp roc
Changing the heads and cam was almost too easy. The only glitch was with the wrong head bo