Before the engine could be...
Before the engine could be fired up with the EFI, we test to make sure the injectors are firing properly and in sequence.
Spitting the fuel into the newly machined manifold are 36 lb/hr injectors from F.A.S.T., along with a 1,000-cfm throttle body from MSD. Of course, now there are sensors to connect: water temp, air temp, MAP (manifold vacuum), TPS (throttle position), IAC (idle air control) and a bung had to be welded in the exhaust for the wide band O2 sensor. The distributor also had to be modified to generate the crank signal and not mess up rotor phasing.
So was EFI worth all the work? Did the direct port injection make up for a rather poor intake manifold design? Check out the graph (Diagram 1), and decide for yourself. In this application, the poor design of the Slant Six's intake was overcome by placing the fuel supply directly in front of each intake port.
when we finished pulling the...
when we finished pulling the little Slant Six to its full rpm, we did get more horsepower with the EFI setup-quite a bit actually. How does 320 at 6,000 rpm sound? Even torque was up to 303 lb-ft at 5,000 rpm.
Ok, so it's not a Hemi, but it is cool in its own way. While doing the math on the computer, theoretically, 1-hp-per-cubic-inch should be easy, but we were thinking more 1.25-hp-per-cubic-inch. So a 225 Slant Six should be capable of 300 horses. We were happy that we surpassed our goal, and Romeo was ready to place the little Big-Bullet in his Dart.