Muscle Mustangs & Fast Fords
Edelbrock Performer RPM Plate Installation - The Flick Of A Switch
We Add 98 RWHP With An Edelbrock Performer RPM Plate.
Just By flicking a switch, output increased by nearly 100 rwhp in the '84 Mustang that was used for this article. That wonderful increase in power came thanks to a plate nitrous system from Edelbrock. Nitrous has long been known to be a cheap and effective horsepower meter. The Performer RPM kit (adjustable to 250 hp) was set at 100 hp, and we repeatedly made 98 more rear-wheel horsepower than our baseline runs in naturally aspirated trim. That equates to approximately a 112hp increase at the flywheel.
The action of flipping the switch refers to us arming the nitrous system, which at wide-open throttle (WOT), adds the nitrous and fuel mixture. Simply stated, nitrous-oxide injection is a way to add additional air and burn more fuel without relying on Mother Nature. Nitrous (N20) is composed of two atoms of nitrogen and one atom of oxygen. The atom of oxygen is what our engines crave, since an internal-combustion engine harnesses the power created when we burn air and fuel. The two parts of nitrogen help to deliver the concentrated oxygen part to the combustion chamber. Once inside the cylinders, the combustion process (and subsequent heat) breaks down the nitrogen and frees the oxygen. Due to the greater oxygen content, additional fuel is required to maintain the correct air/fuel ratio for proper burn inside the cylinders.
A plate nitrous system in carbureted applications requires a simple carb spacer with spray bars running through it. One side feeds nitrous while the other feeds fuel. Nitrous oxide is stored under pressure, inside a bottle, and is delivered to the plate in liquid form. Once it's introduced into the atmosphere, nitrous turns from a liquid state to a gaseous one. It's mixed with fuel and sprayed into the intake runners, through the heads, and into the combustion chambers. The process is simple, effective, and most importantly-cost effective.
Like everything in life, moderate dosages can be healthy, and too much is harmful. We have seen nitrous work great on stock engines, though the owner must exercise restraint and not put too much in at one time or manipulate the tune to push the engine too hard. It's far too easy to load up the big nitrous pills and let it rip.
Edelbrock supplied us with a plate nitrous system designed to work on traditional 4150-style intake flange openings. The system is adjustable from a 100hp shot to a whopping 250hp increase. The kit comes complete with nitrous bottle, lines, wiring, a WOT activation switch, and other stuff to successfully add this system to virtually any carbureted vehicle. Additional equipment installed includes a purge kit, a bottle heater, and quick-release bottle brackets-all sourced from the Edelbrock catalog.
The test vehicle belongs to Justin Burcham of JPC Racing, and this '84 Mustang GT is his former daily driver. The car has been sitting for a few years, and he decided it was time to get it back on the road. The engine is fairly basic-a long-rod 306ci. The crank is stock, and it swings Chevy steel connecting rods and 10.5:1-compression pistons. A mild flat-tappet camshaft features 0.540-inch lift on both intake and exhaust. The heads are a set of Patriot Freedom aluminum castings (180cc intake ports), and the intake is a rather inexpensive Professional Products single-plane piece. Burcham bought the intake from some guy for peanuts, and he now knows why it was so cheap-one runner was cracked. We used JB weld to close it up for the test. Shortly after our photo shoot, an Edelbrock Victor Jr. was bolted to the engine.