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Intake Manifold, Carburetor Combination, and Ignition System Upgrade - 4 Barrels Of 5.0L Fun Part 2
Our '85 Capri Gets An Intake Manifold And Carburetor Combination, Along With A New Ignition System.
Truthfully, we expected a bit more from the intake manifold and carburetor combination, and while we did pick up 2 mph, we're thinking a jetting change may be in order. Unfortunately we didn't have any with us, so we moved on to the Performance Distributors Firepower ignition system. Lucky for the Greek, he got to play crew chief and driver while we took the photos.
The factory plug wires were disposed of quickly, and we ditched the spark plugs as well. PD specified wider plug gaps (0.050 to 0.055-inch) with its Inferno 2 coil and Livewires, so we opened up a fresh set of Autolite 25s, gapped them to 0.052, and screwed them in. We also plugged in the Dyna-Mod and coil connections. The 5.0L immediately sounded better and revved faster upon start up, but would this translate to quicker elapsed times on the track?
Pulling out of the burnout box and up to the line, Xenos pulled the engine rpm to 3,500 and let the clutch out. The first 60 feet passed in a scant 1.91 seconds and he shifted each gear at 5,200 rpm. The Capri tripped the top-end lights in 13.98 seconds at 97.05 mph. That's the first time we saw a 97-mph trap speed, and we wouldn't dip below that the rest of the evening. On the next run, the 60-foot rose to 1.95 seconds, and the quarter-mile time followed at 14.04 seconds at 97.03 mph. We followed this with three 14.0s, and a hard 4,000-rpm launch netted a 1.88 60-foot time, along with a 13.94 at 97.09 mph.
While the mods this time around did not make a significant leap in performance as on our first outing, they have put us solidly in the high-13 to low-14-second range at 97 mph-a 0.2-second reduction in elapsed time and 2 more mph. We'll get ourselves a box of jets for the next time out at the track and see if that might wake things up a bit. We also have a complete true-dual exhaust system that we're going to bolt up to replace the factory Y-pipe, headers and 2.25-inch exhaust. In addition, we've picked out a pair of high-performance cylinder heads and a hot camshaft to get our carbureted 5.0L thumping.