Initial testing was conducted with the popular Trick Flow Track Heat intake manifold with a BBK 75mm throttle body. Boost is delivered by way of a ProCharger D1SC kit with an eight-rib conversion and a large air-to-air intercooler. The baseline runs showed manifold pressure at 18.8 psi at 6,600 rpm. Thanks to the street-driven nature of this beast, the car is run strictly on 93-octane pump gas, but the octane is spiked with a dose of methanol (50/50 mix of methanol and water) via a Snow Performance kit. The Two-Valve mill pushed the Dez Racing DynoJet chassis dyno to 677 rwhp and 564 lb-ft of torque with the long-runner manifold in place.
Swapping to the Edelbrock Victor Jr. 4.6L was fairly simple, but there are several noteworthy factors. The first, we relied on a set of Edelbrock fuel rails, which can cause an issue in some applications. The rails are fine in our application because the engine uses a Big Stuff 3 standalone EFI system. There could be a problem with cars that run a stock ECU and return-less fuel system. The stock fuel rails have a fuel pressure sensor mount, but aftermarket fuel rails don't have a provision for it. Aeromotive offers a sensor adapter that retails for under $50.
Another snag we ran into, thanks to yours truly, was in regards to the inlet elbow that mounts to the top of the Victor Jr. 4.6L intake. I had ordered the nice-looking box-style inlet elbow (PN 3850). The 3850 is a low-profile elbow, but the problem wasn't hood clearance. Actually, it put the throttle body too close to the shock tower, so there was no room for the supercharger tube to connect with the throttle body.
Our solution was to borrow (steal?) another Edelbrock elbow from a pushrod combination in the corner. It goes by PN 3849 but our test piece was 38493, which is coated black. The 3849 and 38493 require an '86-'93 5.0L throttle body and Dezotell grabbed a 80mm unit from inventory. Two other problems presented themselves with using the 38493 elbow. It definitely didn't clear the hood, and the stock throttle cable linkage wouldn't link up.
The first problem, hood clearance, was easily solved with another Edelbrock product, but we didn't get it in time for testing. The proper elbow for this application is PN 3847, which is Edelbrock's ultra-low profile elbow.
The other issue with the throttle cable linkage was easily solved, as Dezotell pulled a setup for an '86-'93 5.0L off the shelf.
No matter which elbow is used with this application, the supercharger inlet pipe will need to be modified or a new one made. Head wrench at Dez Racing, Brian Machie fired up the welder, plugged in a cutter, and grabbed some spare 3.5-inch pipe from the stockpile. An hour later the supercharger was connected to the throttle body via the newly made pipe and a rubber elbow. For those switching from a Trick Flow intake to the Edelbrock one, the alternator will need to be switched back around. Another option is to build two brackets to hold the alternator in place, which is what we did for the test due to time constraints.
For those keeping track, our parts list includes the Edelbrock Victor Jr. 4.6L SOHC EFI manifold (PN 28385), which retails for $289.99 from most mail-order companies. We also used an Edelbrock fuel-rail kit (PN 3639); that will set you back anywhere from $99.99 to $105.99 from most catalogs we referenced. The Edelbrock ultra-low profile elbow (PN 3847) goes for $111.49 for the as-cast version and $124.99 for the black piece. The 80mm throttle body for an '86-'93 5.0L High Output engine is on the list of parts as well. We've seen those throttle bodies go from $230 to $250 from most manufacturers. Dezotell added a few fittings to the new fuel rails, which brought the total cost for this conversion between $770 and $800. That doesn't include the labor, dyno time, or inlet tube fabrication. Also consider another $50 if you need the pressure transducer mount from Aeromotive.
3a The Victor Jr. 4.6L intake features shorter runners than other Two-Valve manifolds on
3b ...Edelbrock’s Brent McCarthy told us the long runners (each corner) are approximately
4 The manifold has all the provisions for the vacuum lines and here is the MAP sensor fit