To say that we were excited about running this test is an understatement. After running the D-1SC from ProCharger on the BPE 6.0L crate engine with impressive results, we couldn’t wait to apply all that wonderful boost to a larger, more powerful 427 LS. Since we planned on running it with the same pulley ratios, it would make for an interesting comparison to see if the difference in power naturally aspirated carried over under boost. We were also interested to see how the boost pressure reading from the larger engine compared against the 6.0L crate engine. Now, toss in running the D-1SC and a larger F-1A-94 on the built LS7 and you have one heck of a dyno day (maybe two). All good stuff to be sure, but we’re getting ahead of ourselves. Before we could perform any testing, we needed a dyno engine, then the two superchargers, then plenty of sleepless nights dreaming about the wonders of boost! Well, two out of three for sure.
The 7.0L LSX engine (code-named The Magnificent LS7) combined an iron, Chevrolet Performance LSX block with forged internals from CP, Carrillo, and Lunati. The displacement came courtesy of the 4.000-inch Lunati Voodoo stroker crank combined with the 4.125-inch bore CP (flat-top) pistons. Connecting the two forged components was a set of 6.125-inch (Bullet series) Carrillo rods. The bulletproof bottom end was purpose built with power-adders in mind, but before adding boost we had to install the naturally aspirated power-adders. These included a pair of GenX 260 LS7 heads from Trick Flow Specialties (TFS), a Brian Tooley Racing (BTR) Stage IV LS7 cam, and an MSD Atomic intake manifold. Additional components include a set of FAST 75-pound injectors, a Comp aluminum front cover, and a Holley 105mm throttle body. The oiling system included a pan, pickup tube, and windage tray from Moroso, while ATI supplied the Super Damper required for blower use. Run on the dyno in naturally aspirated trim with a Holley HP EFI management system and 1 7/8-inch Hooker headers the LS7 produced 653 hp at 6,500 rpm and 593 lb-ft of torque at 5,000 rpm.
After success with our naturally aspirated combination, it was time for the first of the two self-contained ProCharger superchargers. Capable of supporting 925 hp, the D-1SC was installed using the supplied blower mounting and tensioner brackets. ProCharger supplied a number of different blower pulleys and the required 7.40-inch crank pulley. Having limited experience with this supercharged LSX we started with the most conservative, the 4.25-inch blower pulley. This turned out to be a good choice for the 427, as the combination produced a peak boost pressure of 9.9 psi. Lest you think the boost was a tad on the low side, the D-1SC combination produced 944 hp and 794 lb-ft of torque. Rather than try a different blower pulley, we installed the larger air-to-air intercooler supplied with the F-1A-94 supercharger. The high-flow intercooler increased boost pressure to the engine (with no change in pulley diameter) and allowed the 427 LSX to top the 1,000hp mark with peak numbers of 1,003 hp and 865 lb-ft of torque!
Having exceeded 1,000 hp with the D-1SC you might think we would be satisfied, but you’d be wrong. The D-1SC was just the appetizer. The main course was the larger, more powerful F-1A-94 supercharger. According to ProCharger, the F-1A-94 flowed 1,575 cfm and was capable of 38 psi and 1,200 hp. Having exceeded the peak rating of the D-1SC by more than 75 hp, we were anxious to see if the F-1A-94 followed suit. The self-contained nature of the F-1A-94 meant hookup was a breeze, especially since the unit uses the same brackets as the D-1SC (and even the P-1SC, which makes upgrading easier and less expensive). We did take the liberty of increasing the injector size to 80-pound Accel units before installing the larger intercooler and blow-off valve.
Starting with the 4.25-inch blower pulley, the F-1A-94–equipped LSX produced 1,161 hp and 940 lb-ft of torque at 15.8 psi of boost. Close to the 1,200hp rating and we weren’t even breaking a sweat yet! Looking for a touch more power, we replaced the 4.25-inch blower pulley with 3.85-inch version. The result was an increase of roughly 2 psi of boost and a jump in power to 1,267 hp and 1,041 lb-ft of torque. Using the ProCharger supercharger, we nearly doubled the power output of our already powerful LSX, which proves that everything is better with boost!
427 LSX — NA vs. ProCharger D-1SC
Our worked over LS7 produced plenty of power, even in naturally aspirated trim. Equipped with the TFS GenX 260 heads, MSD intake, and BTR Stage IV cam, the 427 produced 653 hp and 593 lb-ft of torque. After installation of the intercooled D-1SC from ProCharger (with 4.25-inch blower pulley), the supercharged numbers jumped to 944 hp and 794 lb-ft of torque at a peak boost level (in the intake) of 9.9 psi. Before installation of the larger F-1A-94 blower on the LSX, we tried the larger intercooler supplied with the F-1A-94 kit. The additional flow offered by the larger core increased the boost supplied to the engine (with no pulley change) to 10.7 psi. This increased the power output of the D-1SC–supercharged LSX to 1,003 hp and 865 lb-ft of torque.
427 LSX — NA vs. ProCharger F-1A-94 (4.25- & 3.85-inch Pulleys)
After exceeding our expectations with the D-1SC on the 427, we installed the larger F-1A-94 supercharger. Equipped with the same 4.25-inch blower pulley (though a different internal step), the F-1A-94 supplied a peak of 15.8 psi to the 427 LSX. Naturally, the power was up in relation to boost, as the supercharged 427 produced 1,161 hp and 940 lb-ft of torque. After replacing the 4.25-inch pulley with a 3.85-inch version, the boost jumped to over 17 psi, allowing the LS7 to produce 1,267 hp and 1,041 lb-ft of torque. Obviously, the power ratings offered by ProCharger were conservative, as we managed to exceed both the 925hp rating for the D-1SC and the 1,200hp rating for the F-1A-94. We love it when a supercharger system like the ones from ProCharger under promise and over deliver!
01. Sporting 427 cubic inches, the Magnificent LS7 featured a Lunati crank, Carrillo rods, and CP pistons all stuffed neatly inside the Chevrolet Performance GM LSX block from Gandrud Chevrolet. Note also the Fel-Pro MLS head gaskets and ARP head studs. The LS7 had an 11:1 compression ratio.
02. Covering the BTR Stage IV cam was a Comp front cover and topping the LS7 was a set of CNC-ported GenX 260 LS7 heads from Trick Flow Specialties.
03. Run on the dyno with an MSD Atomic intake, Moroso oiling system, and FAST injectors, the naturally aspirated LSX produced 653 hp at 6,500 rpm and 593 lb-ft of torque at 5,000 rpm.
04. After running the naturally aspirated engine, installation of the ProCharger supercharger began with the first of two mounting plates. Note that the mount offered a variety of mounting positions, making the system very flexible in terms of installation.
05. Next came the tensioner and blower mounting plate. Four bolts were used to secure this to the primary plate.
06. First up on the LSX was the D-1SC from ProCharger. Capable of supporting up to 32 psi, 1,400 cfm, and 925 hp, the D-1SC was plenty powerful for most street cars.
07. This ATI Super Damper (PN 918853) was installed so that we could bolt on the ProCharger crank pulley and have everything line up correctly.
08. The supplied (8-rib) 7.64-inch crank pulley was secured to the ATI Super Damper using the supplied hardware.
09. ProCharger supplied a number of different blower pulleys, but we started (and ended) the D-1SC test with the largest of the bunch (4.25-inch).
10. Fuel for the D-1SC was supplied by a set of FAST 75-pound injectors.
11. Tuning the naturally aspirated and supercharged combos was this Holley HP EFI management system.
12. The ProCharger D-1SC kit included this air-to-air intercooler. The cooler was responsible for dropping the inlet air temps by more than 100 degrees. The tubing diameter on this intercooler is 3 inches.
13. Run on the dyno with the D-1SC, the supercharged LSX produced 944 hp (6,600 rpm) and 794 lb-ft of torque (5,600 rpm) at 9.9 psi. After installation of the larger intercooler supplied with the F-1A-94, the power jumped to 1,003 hp (6,500 rpm) and 865 lb-ft of torque (5,500 rpm). Considering ProCharger rates the D-1SC at 925 hp we were pretty happy with that number.
14. After taxing the limits of the D-1SC system, we installed the more powerful F-1A-94. The F-1A-94 was capable of supporting 38 psi, 1,625 cfm, and 1,200 hp. As we found out with the D-1SC, the max power numbers were certainly conservative. It also has a massive 4-inch inlet and the impeller has a max rpm of 74,000!
15. We liked the fact that both the D-1SC and F-1A-94 were self-contained, meaning it was not necessary to punch a hole in the oil pan to serve as a drain. A few ounces (4 ounces to be precise) of the supplied oil was all it took.
16. We also loved the easy-to-adjust belt tensioner, as even at over 1,200 hp, the 8-rib system never missed a beat. ProCharger does offer a cog system, but they state that many customers have great luck with the ribbed serpentine belt, even over 1,300 hp.
17. Given its increased flow and power potential, the F-1A-94 was supplied with an even larger air-to-air intercooler. The F-1A-94 cooler featured both increased core thickness and 3.5-inch inlet and outlets.
18. Knowing the power level was increasing, we stepped up to a set of 80-pound injectors from Accel. The stock fuel rail was also replaced by the aluminum version from Holley. The taller injectors required us to fabricate our own L-shaped mounting brackets.
19. With the tremendous flow potential of the system, ProCharger supplied one of their massive blow-off valves to eliminate the pressure spike that can occur when you shut the throttle at max rpm/boost.
20. Run with the F-1A-94 and a 4.25-inch blower pulley, the supercharged LSX produced 1,161 hp and 940 lb-ft of torque at 15.8 psi (Rocket 112 race gas). After stepping down in blower pulley size to 3.85-inch on the F-1A-94, we were rewarded with 1,267 hp (at 6,500 rpm) and 1,041 lb-ft of torque (at 5,200 rpm)! More than advertised and were weren’t even maxing out the blower yet.