The "root" (excuse the pun) of our stroked LT1's power will come from this shiny D-1 Proch
Adding forced induction to a stout engine has long been considered the epitome of performance when attempting to unbridle the most in power and torque. From Top Fuel to Pro Street, aluminum lungs are standard equipment-both in terms of throttle response and gawk appeal. (What's cooler looking than a polished 8-71 sticking out of the hood?). But when it comes to unleashing the most from today's computer controlled EFI-equipped engines, however, roots-style blowers are not-surprisingly missing from the scene.
Have they lost their visual allure? Not likely-it's simply a matter of logistics: First, they require a complete revamp of the engine (Few, if any late-model owners want to take a plasma cutter to their new cars). And, in most instances, they will automatically render the modern machine illegal in the eyes of the ever-increasing fraternity of smog cops.
Enter the age-old second-tier huffer known as the centrifugal supercharger. These belt-driven, high-winding, impeller-spinning blowers have been around for nearly as long as their top-of-the-engine-mounted brethren. But, until the advent of computer-controllable ignition and induction systems, they've failed to consistently reach the power and dependability levels of the roots design.
With the 383 on a stand, Bob Vrbancic bolted on the massive billet bracket (complete with
But in the high-tech arena, the centrifugal supercharger is second to none. So, when we started out to build a powerhouse LT1 stroker, with its combination of electronic fuel injection and OBD II computer system, there was no second-guessing the choice of adding a belt-driven 'charger. For our project, we decided upon the increasingly popular Procharger from Accessible Technologies Incorporated (ATI, for short).
We've had previous experience with the gurus at ATI involving both EFI and blow-through carbureted applications, and feel extremely confident about their products. (You may recall our '96 Camaro convertible, which has the company's smallest unit on its stock LT1 and made around 400 rear-wheel horsepower and more than 500 foot-pounds of torque!) For this application, however, we were talked into stepping up from the smallest unit to the more potent D-1 version. With a larger intake tract and impeller, the D-1 opened up the possibilities of power and torque levels that we've been eyeing. In a nutshell, the bigger blower bolted on the bigger engine should equal bigger performance.
But, you'll have to wait until next month to see the results, as this segment deals with the installation of the unit on its custom bracket. (Since the engine bay of the fourth-generation Camaro-which is where this bad boy will reside-is less than cavernous, the billet aluminum mounts that came with our unit were hand machined to make sure the blower was exactly where it needed to be.)
In addition to the installation procedure, we've included a retrospective on the work that went into the stock LT1's intake manifold by the wizards at Arizona Speed and Marine. From welding on bosses for the nitrous oxide nozzles to porting and blending the runners, you'll see why this manifold will be our Procharger's best ally in making big power numbers with our LT1 383.
"It has to go this way," exclaimed Bob. When we did finally determine the correct clocking
We had to fabricate different length spacers to align the blower pulley with the crank pul
With the blower in place, everything else was a simple installation procedure. The blower'