Here we go! Our 383 stroker gets loaded onto the dyno cart at Vrbancic Brothers Racing. At
Seven-hundred horsepower? From a late-model computer-controlled engine? Are you guys crazy? And you want to drive it where? On the street? On pump gas? Good Luck!
We all make goals. It's what carries us on in life. We aim for that bigger paycheck, strive to lose an extra pound or two, or plan for that house in the country with a big yard for the kids to play in (or a garage for us to play in). We would become pretty complacent if we didn't keep reaching for the seemingly unreachable. So when it came to designing the ultimate late-model street powerplant, we had some goals, too. Three to be exact: 700 horsepower, 600 foot-pounds of torque, and a powerband that would enable us to use this potent package on the street-realistically! Did we attain them, you wonder? Keep reading...
To refresh your memory about this project: Our intention when we hooked up with Frank Beck at Beck Racing Engines in Phoenix, Arizona, was to build a late-model LT1 using the best parts available to create a bulletproof, high-power street engine. To begin with, we had a factory block converted to four-bolt mains and had it meticulously machined to accept a set of oversize SRP forged slugs and a stroked Cola steel crankshaft. To be sure that our reciprocating assembly was up to the task of handling 700 ponies, we added a set of Manley H-beam connecting rods, a Titan Sportsman adjustable oil pump housed in an extra-capacity Billet Fabrication aluminum oil pan, Crane valvetrain components, and surefire ARP fasteners throughout.
This is the McLeod billet steel flywheel. Note the studs for the dual-disc setup. Here the
Once we had assembled the components for a solid short-block, we turned our attention to the induction side of things. First, we chose to use a set of replacement cylinder heads from Airflow Research. The aluminum big-valve (2.05-inch intake, 1.60-inch exhaust) castings have a tremendous flow capacity (both before and after BRE massaged them with a die-grinder) on both the intake and exhaust sides, and they retain the factory's reverse-flow cooling technology. Feeding the "pump" is an Arizona Speed and Marine reworked LT1 EFI direct-port intake manifold that has been Extrude-honed and modified for later use with nitrous oxide injection, and a well-machined billet 58mm throttle body.
Injectors are MSD high-flow, high-pressure units that are fed fuel via a boost-referenced fuel regulator and high-pressure fuel pump from Aeromotive Systems. A Speed-Pro C-Com engine management system from Federal-Mogul makes it all work in harmony (and can be tuned for maximum power using a PC). GM Performance Parts provided the majority of the supporting items, such as fuel rails, a water pump, the Opti-spark ignition system, a timing cover, etc. ATI sent us one of their super Super Dampers, Tilton fired off a small-yet-powerful starter motor, Carbon Components carbon fiber valve covers beautifully hide the roller rockers, and McLeod furnished a nicely machined, heavy-duty flywheel and clutch assembly. To say that this bad boy is going to hook up is most definitely an understatement.
But the biggest part of the equation in our quest for 700 horses is the addition of the D-1 Procharger from Accessible Technologies. The D-1, which is a step up from the company's entry-level P600b unit, flows roughly 25 percent more than it-and also has a higher peak efficiency, the trade-off being the flatness of the boost curve (the D-1 is peakier). Typically, the engineers at Procharger don't recommend using the P600b on anything making much more than 650 hp (max), whereas the D-1 works nicely up to and above 850 ponies, which was perfect for this project.
Machining and long-block assembly were done at BRE's Phoenix shop, while all of the peripheral add-ons were installed by your dedicated staff at Super Chevy. Once the basic engine was together, we put it in the bed of a small truck and headed toward Vrbancic Brothers Racing and their state-of-the-art DTS dyno facility to see where we stood on the horsepower curve.
Here's our stroker in place on the DTS dyno. Note the stainless steel braided line leading
We used a set of Vrbancic's dyno headers for our tests rather than the long-tube pipes sen
This is the Speed-Pro Wide Band O2 sensor that came with our C-Com setup. Each sensor is c