In the Eclipse session, our Diamond Star got a double injection of horsepower and torque with the addition of an intake, exhaust, and header, the three most common bolt-on power adders. Our final numbers were impressive, with horsepower at 117.2 hp and torque at 121.6 lb-ft. More importantly, the power and torque were present not only at the peak points, but almost consistently delivered throughout the powerband. Examining the previous power graphs with a magnifying glass and a fine-toothed comb showed increases as high as 10-12 hp at some points, especially in the lower rpm regions. This is especially helpful for all the drag and stoplight racers who want that extra push off the line, and even more helpful in a "daily-driving" situation, where rpm stay relatively low.
Performance ComponentsThe last installment for the 420A motor saw the addition of basic performance bolt-ons-an intake system, an exhaust system, and a header. Our net gain was more evident in torque than peak horsepower, with torque output jumping from 112.9 lb-ft to 121.6 lb-ft. Peak horsepower went from 113.0 hp to 117.2 hp. While this doesn't sound like a whole hell of a lot, the true tale lies in overlaying the graphs. The entire powerband shifted up in this range with peak gains often higher than the maximum peak horsepower. See our previous issue for more on these tests.
This issue, we are testing how well the engine takes to fine-tuning as we add adjustable cam gears. The addition of the gears should "clean up" the power curves and extract more horsepower hidden within the engine and its components. Adjusting the camshaft timing parameters to match the performance components that are already installed boosts the motor's efficiency and helps to unleash more power and torque. Finally, we will add the mother lode of all bolt-on power adders-the nitrous oxide system-to see just how high we can fly.
Our adjustable cam gears come from AEM. The gears are machined from 6061 T-6 billet aluminum material for maximum strength. The markings and graphics are laser-etched and painted in white for easy visibility when tuning the vehicle. The gears are precision machined to match factory teeth; this eliminates premature wearing of the belts and the gears themselves. With the appropriate tuning instruments, the cam timing can be dialed in to open and close the valves at the exact times and for the exact duration needed to maximize the efficiency of the motor.
Since the number-one complaint of Eclipse RS owners is the lack of a turbocharger, we decided to test an alternate form of whip-ass-the throttle-in-a-bottle, 10 lb of laughing gas, nitrous oxide. We didn't want any to be able to say, "Don't worry about that car-it's a non-turbo model." Nitrous Express' universal single fogger kit is just the solution we were looking for. The kit comes complete with everything needed to make our Eclipse truly shine: bottle, jets, lines, solenoids, and the company's patented Shark nozzle, which atomizes the fuel and nitrous more efficiently. The bottle in the stage one EFI kit holds 10 lb of laughing gas, enough to get you through a day at the races or an evening of fun-filled excitement. A system power switch and full throttle switch are included to make sure the nitrous is on when you need it. Stainless steel braided lines and anodized fittings ensure the integrity of the nitrous system.
Before we start trying to make more power, however, we want to make sure that everything is running the way it's supposed to, especially after all the hard driving down between the original dyno session and the new one. So, a basic tune-up will be first on the list-changing the oil with Royal Purple's engine lubricant and making sure the spark plugs are fresh and can handle the increased demands of the nitrous system. For this task we chose NGK's BKR7E's plugs.