It is no secret that we are fans of Chevrolet Performance crate engines, especially big ones. I mean, if there is anything better than a Chevy small-block, it has to be a big-block, right? Naturally, this holds true of crate engines, which offer much more than a simple displacement jump. Crate engines, especially those offered by GM, offer a number of positive attributes, not the least of which includes reliability and accountability. Unlike many of the low-buck, crate engine warehouses, the GM stuff has all been thoroughly tested for both strength and durability. Most aftermarket sellers simply do not have the facility or finances to subject their offerings to such rigorous testing. One thing about a GM piece, you know it’s going to do what they say it does. Every bit as important is the fact that, if you do have an issue, GM will be there to stand behind their work. This confidence comes partly from the extensive testing, but it is nice to know that you are getting a quality product and a company stands behind it.
For us, going big meant selecting a ZZ454 crate engine. Being a big-block, the combination was already sporting sufficient cubic inches, but the ZZ454 offered more than just displacement. The crate engine featured a four-bolt block, small-chamber aluminum heads, and a hydraulic roller camshaft. Thanks to a cam and valvetrain upgrade in our last installment, the 454 was now making even more power. Run with a Meziere electric water pump, the big-block thumped out 538 hp at 5,800 rpm and 518 lb-ft of torque at 4,500 rpm.
Satisfied with our baseline, it was now time to supply some boost. For the street-oriented big-block, we chose a ProCharger P-1X centrifugal supercharger. Thanks to a redesigned impeller and volute, the P-1X was designed to provide even more power than the already powerful P-1SC. ProCharger designed the more powerful P-1X to bolt directly to the existing blower mounts designed for the P-1SC, making stepping up to the revised blower simple and easy. For our needs, the P-1X was ideally sized to provide substantial power gains with minimal boost. Though this was a low-boost, blow-through carbureted application, we decided to combine the P-1X with an air-to-water intercooler from ProCharger. This allowed us to safely maximize power production and also to try a number of different pulley ratios and the attendant boost levels.
Before we could start testing, we first replaced the Holley 950 Ultra XP carburetor with a blow-through 850 Holley carb from Carburetor Solutions Unlimited. The dedicated blow-through carb featured billet annular boosters, calibrated metering blocks, and boost-referenced power valves. This combination allowed us to dial in the air/fuel curve of the supercharged application at a variety of different boost levels. After installation of the ProCharger P-1X and intercooler, we started out with the largest blower pulley to provide the lowest boost pressure. The 4.50-inch blower pulley was combined with a 7.65-inch crank pulley to provide a peak boost pressure of 5.0 psi at 6,000 rpm. This combination increased the power output of the modified ZZ454 from 538 hp and 518 lb-ft of torque to 717 hp and 644 lb-ft of torque. Stepping up in boost with a drop in blower pulley size to 4.25-inches resulted in a peak boost pressure of 6.0 psi, where the blown big-block made 759 hp and 677 lb-ft of torque. The final pulley swap to 4.0-inches resulted in 7.1 psi and an even 800 hp (800.4 hp to be exact). Running just over 7 psi, the ProCharger P-1X improved the power output of the ZZ454 crate engine by an impressive 262 hp.
Though we could have easily called it quits with a successful dyno session at this point, we decided to run a couple more tests. What the heck, we were already there, right? The next test involved the installation of a radiused air entry on the inlet of the P-1X supercharger. The blower was still equipped with the 4.0-inch pulley that produced 800 hp, but thanks to the extra airflow offered by the radiused air entry, the boost and power both increased. The peak boost registered 7.7 psi, while the power output reached 816 hp. The peak torque was up as well, from 716 lb-ft to 728 lb-ft. Improving the airflow into the blower definitely improved the flow out of the blower. The final test of the night was to replace the P-1X supercharger with the larger, race spec F-1A-94. To keep boost at a reasonable level, the F-1A-94 was run with a 4.25-inch blower pulley. This resulted in a peak boost pressure of 10.6 psi and a peak power output of 945 hp and 828 lb-ft of torque. Blown big-blocks rule. If your lazy big-block needs a wakeup call, there is no better alarm clock than boost from a ProCharger supercharger!
1. The ZZ454 had been previous upgraded with a healthy Comp XM284HR cam that offered 0.547-inch lift, a 230/236-degree duration split, and a 112-degree LSA.
2. The ZZ454 also received a rocker arm upgrade, from the ball-pivot stockers to a set of aluminum Comp Ultra Pro Magnums. The pushrods were likewise upgraded to hardened units to work with the guideplates.
3. Run on the dyno with a Weiand Track Warrior intake, Holley 950-cfm Ultra XP carb, and MSD Pro-Billet distributor, the naturally aspirated 454 produced 538 hp at 5,800 rpm and 518 lb-ft of torque at 4,500 rpm.
4. After establishing our naturally aspirated baseline, we commenced with the installation of the ProCharger kit starting with the blower mounting bracket.
5. Since the ZZ454 was designed as a street engine, we installed a street centrifugal supercharger in the form of a P-1X from ProCharger. The P-series of superchargers are great for standard-compression engines that will be running pump gas.
6. The efficient impeller design of the P-1X was easily capable of supporting our intended power level. Upgrading to “bigger” units, like the D- and F-series blowers, is easy since they all utilize the same mounting bracket.
7. We installed a 7.65-inch crank pulley on the factory damper using the supplied hardware.
8. The kit featured this adjustable tensioner to ensure adequate belt tension on the supercharger belt. Once properly tensioned, we experienced zero belt slippage.
9. Our boosted big-block was fed with an 850 blow-through carburetor featuring boost-referenced power valves.
10. Carburetor Solutions Unlimited (CSU) supplied the necessary carb bonnet to ensure proper airflow distribution to the carburetor.
11. Though we ran relatively low boost on the ZZ454, we still installed this air-to-water intercooler supplied by ProCharger. The core was supplied ambient dyno water during testing.
12. The big-block was run with a variety of different blower pulley sizes. Extra power from the ProCharger supercharger was a simple pulley swap away.
13. Even at the lowest boost level of just 5.0 psi, the ProCharger P-1X supercharger improved the power output of the ZZ454 from 538 hp and 518 lb-ft of torque to 717 hp and 644 lb-ft. After stepping down in blower pulley size from 4.5 inches to 4.25 inches, the boost picked up by 1 psi and the power jumped to 759 hp. The next step down in pulley size to 4.0 inches upped boost by 1.1 psi and allowed to ZZ454 to reach the 800hp mark
14. After running the various pulley sizes, we even tested a radiused entry on the opening of the supercharger. The entry improved boost production by 0.7 psi and power by 16 hp.
15. The final test involved replacing the P-1X with an F-1A-94 supercharger equipped with a 4.25-inch blower pulley. Compared to the P-1X with the same pulley, the F-1A-94 increased the boost by 3.5 psi (to 10.5 psi) and the power output by 145 hp for a peak of 945 hp on higher-octane race gas.