KJ Jones
Brand Manager, 5.0 Mustang & Super Fords
December 1, 2008
Photos By: KJ Jones
Watching a dyno session from this vantage point is awesome. Because of the extremely loud noise inside the dyno cell (from the engine and high-powered fans), Eugene and Ernie rely on an interesting system of hand and eye signals to communicate with each other while preparing an engine for dyno runs.

The dyno test ultimately proved that our AFD-headed, Comp solid-roller-cammed, Wilson single-plenum intake'd small-block is built to rev high. The engine zings smoothly to 8,000 rpm on muscle, reaches the same plateau even quicker when nitrous is applied, and lays down impressive power at the crank either way.

Due to time constraints, we didn't get too deep into tuning Boss 340 in this session (idle and such). Instead, Westech's Ernie Mena and Eugene Walde conducted sweeps within specific rpm ranges, which allowed Ernie to make the appropriate changes in ACCEL's EFI Thruster's fuel and timing tables to stabilize the WOT air/fuel ratio at 12.8 with 37 degrees of timing.

As you see in the chart, our project engine likes nitrous oxide. With a 250 shot from the Zex EFI Perimeter Plate nitrous system, Boss 340 gained tremendously at the flywheel. We cited the engine's solid-roller camshaft as a contributor to its ability to reach 8,000 rpm with literally no effort, but the cam's 112-degree lobe separation and 0.274-inch exhaust duration at 0.050 are big reasons why our engine is so nitrous compliant.

With 598.56 horses ready to play and over 200 or more available with Zex's nitrous kit, we can't wait to get the engine in our Boss '90 LX and see what the combination will do on the chassis dyno and, of course, on the dragstrip!

An optimal air/fuel ratio is the most-important element of dyno-tuning a naturally aspirated or power-adder-assisted engine. With ACCEL's EFI Thruster, the primary changes for Boss 340 are made in the base fuel and timing tables. "We didn't do much with fuel on the low end for this test," says Ernie. "We basically looked at fuel injected at 5,500 rpm and above, as that's where the camshaft in this high-revving engine really starts working."

This is ACCEL's 1,350-cfm throttle body. If we were dealing with carburetors, this piece would be similar to a 1250 Dominator. We believe there may be significant all-motor power gains. There definitely will be improved power-adder performance from Boss 340 when we give this baby a try. Time fell short for installing it during this dyno session, but you can bet we'll use this piece once the project car is complete and mounted on a chassis dyno for rear-wheel-horsepower testing.