Novi 2500 Supercharger Dyno Test - Nouveau Novi

Autolite’s 3910 (left) is an excellent cold spark plug for boosted, high-horsepower street/strip engine’s like T-top Coupe’s. However, the all-new 3910X plugs (right) are super cold and more in tune with setups that make upwards of 1,000 hp. “The 3910X sticks farther into the combustion chamber and raises the compression ratio slightly, while maintaining a cold heat range,” according to Autolite’s Jay Buckley. The new plugs, inspired by NASCAR race engines that were having issues with burning up their spark plugs’ side wires during 500-mile races, have eight individual firing edges, which don’t require as much voltage as standard plugs. The efficiency results in increased dwell time and produces a bigger flame kernel for improved combustion.

After experiencing piston meltage in two engines that were not intercooled, we fully understand the importance of ensuring the air charge for our new engine/blower combination remains cold. We went through approximately 140 pounds of ice during our two days on the dyno. That math breaks down to roughly 10 pounds of ice (added to 2 gallons of water) per run. At the track, nearly 15 pounds of cold cubes are used for one pass. Throughout our time on the dyno, the 353’s air temperature averaged 90 degrees (measured at the intake manifold) and never went above 117 (on one pull with low ice)—a dramatic improvement over the 278-degree air that wreaked havoc on the original engine’s pistons.

Extreme Automotive’s lead technician, Saul “The Surgeon” Gutierrez (right), handled the driving during the dyno segment of the project. Brian manned the laptop and dialed in XFI 2.0 calibrations for street and dyno/dragstrip performance. Of course, with an aggressive setup like that of T-top Coupe, tuning is performed in stages, working in the lower rpm range first to establish air/fuel targets, and then progressing into the full-throttle/big-boost runs.

Here is the dyno graph of T-top Coupe’s first venture into the land of big steam (866 rear-wheel horsepower/734 lb-ft of torque). This run was made with the coupe’s original A.R.E. Performance & Machine-built, AFR-205-headed, 350ci bullet and a non-intercooled Novi 2000 that made 20 psi of boost with a 10-rib belt.

This graph corresponds to the 2K II column in the data chart—our second test, with the Novi 2000’s supercharged air now intercooled and a 30-tooth cog pulley bolted to the blower’s snout. The engine also has been punched out to 353 cubes and upgraded with JE flat-top pistons and AFR’s 225 cylinder heads. While there appears to be a marked performance difference, the new setup is far from the underachiever that the data may lead you to believe. We think that despite the changes, the updated Novi 2K package hit a wall at 6,130 rpm because the new engine is actually a lot more efficient than the original powerplant. The smaller 205 heads on the 350 actually created backpressure in the intake tract, which in turn increased boost. Because of the intercooled combination’s efficiency, we’re not too sure increasing blower speed will help produce bigger numbers, either. On the whole and when looking at the difference with an apples-to-apples mindset (despite what appears to be a loss of 60 hp), the new combination act

Graph and numeric dyno data for the Novi 2500 (the 2500 column on the chart) clearly supports Paxton’s claim that its all-new blower is a monster in the higher-rpm range. Although the 2500 appears sluggish between 4,500 and 5,000 rpm, it literally comes on like gangbusters at 6,000, and takes off from there. Again, the 353’s efficiency allows this package to make more power than we saw in both Novi 2000 tests with less than 20 psi of boost. We have to put on record that our Novi 2500-blown engine was well on its way to making more than the charted 908 hp. We’re not certain the thousand ponies (at the feet) we hoped for were there. But had we not aborted the run at 6,500 rpm for a condition that we think may have been converter shudder, the combination definitely would have made power beyond 7,000 rpm, and come close to the magic number.