Steve Baur
Former Editor, Modified Mustangs & Fords
July 14, 2016

With all of the whiz-bang boost junkies jumping on the Coyote bandwagon, it is easy to forget that traditional gearheads still look to carburetors and solid-roller camshafts for building horsepower. Adding a power adder to that old-school combination works much the same as it does on a Coyote engine, and nitrous oxide injection is still a very viable way to boost power output and improve on-track performance. Taking it a step further, adding a progressive controller to your system can improve performance by allowing you to fine-tune the nitrous delivery to suit track or traction conditions.

There are more nitrous oxide companies in the aftermarket today than ever before, and your choices are thus plentiful. When we wanted to equip a particular Fox-body Mustang with a system, we looked to Edelbrock because of the options the company offers, as well as the fact that Edelbrock offers its own progressive controller—think of it as a one-stop shop.

A single-stage plate system is as simple as it gets when it comes to carbureted nitrous systems, yet they can pack quite a punch. The Edelbrock Performer RPM nitrous system we used in this test can deliver anywhere from 100 to 250 extra horsepower just by changing the jets in the lines. The Performer RPM system steps up the solenoid size to accommodate the higher power levels. The nitrous and fuel mixture is delivered through spray bars located within a 1/2-inch-thick aluminum plate that mounts between the carburetor and intake manifold—keep that measurement in mind should your engine-to-hood clearance be a bit tight to begin with.

The base Performer RPM kit (PN 70050) retails for around $690, but we splurged a bit on extras with this installation, starting with the optional kit (PN 70033) with a polished nitrous bottle, which brings the price up to around $800. We also ordered Edelbrock’s bottle heater (PN 72700, $190), 1 1/2-inch nitrous pressure gauge (PN 73800, $54), safety blow-down tube (PN 72960, $30), and progressive nitrous controller (PN 71900, $515).

Our test vehicle for this installation is a Fox-body Mustang packing a healthy Windsor powerplant to begin with. It is a 408ci engine with Airflow Research 225 cylinder heads, a 0.688-inch lift solid-roller camshaft, an Edelbrock Super Victor intake manifold, an 880cfm ProForm carburetor, and a 12.5:1 compression ratio.

For the actual installation of the nitrous kit, we turned to the capable staff at Burnyzz American Classic Horsepower in Ocala, Florida. Burnyzz sells all sorts of classic muscle cars and late-model performance vehicles, and it also has a full-service shop that can perform everything from restorations to performance installations and dyno tuning. Spend the day there and you’ll see just about everything and anything come in and out of the garage doors.

Post-installation, we trailered the Mustang on over to Orlando Speed World (OSW) in Bithlo, Florida, for some on-track testing. OSW, home of the Worlds Street Finals, is under new ownership as of a few years ago, and the place is better than ever. Even on a test-and-tune day, the track prep was excellent, which made for a great racing surface to test on.

Just about anyone with basic automotive knowledge can install one of these systems, but you’ll want to make sure you use it per the manufacturer’s recommendations to get the maximum performance and system longevity out of it. If you’ve been considering a nitrous setup for yourself; do it, because you’ll appreciate the ease of install and the incredible bang for the buck results.

1. To get the polished bottle included with the Performer RPM nitrous oxide kit, we ordered Edelbrock PN 70033. Short of the nitrous oxide itself, the kit comes with everything you need to boost engine performance by 100, 150, 175, 200, or 250 hp.

2. Accessorizing your nitrous oxide kit is easy, as Edelbrock offers a multitude of options. The company has worked long and hard with racers everywhere to be able to offer what each one might need to improve performance. We spec’d out Edelbrock’s bottle heater, nitrous pressure gauge, purge solenoid, and progressive nitrous controller. Not pictured is the blow-down tube, which is required for NHRA competition when the bottle is in the driver’s compartment, and generally a good idea if you’re installing the system in a street car where the bottle may reside in a hot environment for an extended amount of time.

3. Master fabricator, electrician, and all-around badass Dru Buckley at Burnyzz was tasked with overseeing this install, and here he is marking where the bottle brackets will be mounted to the floor of the car. Problem is, there is a boxed framerail right beneath the brackets, which would make running a bolt through difficult.

4. Buckley’s solution was to create a studded bracket to bolt the bottle bracket to, and weld it to the floor.

5. First, we needed to remove the factory sound deadening and paint from the floor to get to bare metal for welding.

6. Welding on a Fox-body Mustang floor can be tricky because it’s pretty thin, but Buckley made it look easy. He finished off the new mounts with some spray paint to prevent corrosion.

7. Moving on to the front end of the car, car owner Tim Babcock removed the carburetor in order to add the Edelbrock nitrous oxide plate. Babcock uses an 880-cfm ProForm carburetor on his 408ci Windsor powerplant, which sees a lot of use in grudge racing.

8. Edelbrock offers the Performer RPM nitrous oxide kit with square-bore plates like we used with our application, or spread-bore plates. They are 1/2-inch-thick aluminum, so your carb and air cleaner height will go up just a bit. Make sure you have the clearance before clicking Buy Now on your favorite speed shop website.

9. The number one rule when assembling a nitrous oxide system is not to use Teflon tape; you always want to use the paste on the fittings. The second rule should be to use filters before the solenoids. Debris in the lines is the main cause of solenoid failure. Edelbrock includes these filters with the kit.

10. We used the supplied fittings to attach the purge valve to the nitrous solenoid; purging a nitrous system ensures that the liquid in the bottle has not changed to gas in the supply line. When it does this, the initial hit is a bit softer. Also, if you are bracket racing or need repeatability for any reason, purging the line will ensure that you get the juice every time.

11. Mounting brackets are included for the solenoids. Where you mount them is largely up to you and your particular plumbing situation. While we mounted the fuel solenoid on one of the carburetor bolts to bring it closer to its supply line, the nitrous and purge solenoids were mounted onto the intake manifold.

12. The nitrous supply line was run through the floor, through the tubular subframe connector, and up to the engine compartment. Buckley likes to use 3M strip caulk to seal the hole where the nitrous line runs through the floor. The stiff yet pliable material will keep the elements out and also keep the line from chaffing on the edge of the hole.

13. Maintaining a consistent bottle pressure is essential for repeatability, whether you are bracket racing or looking to get good data on other changes to the car.

14. To engage the nitrous system, Edelbrock includes a full-throttle microswitch as well as a single toggle to turn on the power. In this application we employed the microswitch in conjunction with the transbrake button, and used the current switch panel in the console to arm the system and operate the purge. The car owner will be moving the functions to a new switch panel mounted on the halo bar of the rollcage, so be sure to consider future changes when planning out your system and wiring it up.

15. Edelbrock’s nitrous controller has been on the market for some time, and it has proven itself time and again to be dependable and very user-friendly. The controller uses pulse-width modulation to regulate the amount of nitrous being delivered by the solenoids over a period of time. You program the unit using the LED display and touch switches, and it stores your program in its built-in memory. Features of the controller include a plus-12-volt timer output for auxiliary output such as ignition retard or additional nitrous stages, single or dual nitrous ramps adjustable from 0 to 9.999 seconds, solenoid duty cycle adjustment from 10 to 100 percent, separate nitrous and fuel solenoid outputs, an integrated battery voltage monitor, and of course a complete wiring harness and user manual.


Juicing for Power

For track testing we went with the 175hp jets to start with, as it should be a good amount to test traction and the function of the progressive nitrous controller.

The nitrous system was plumbed with a dedicated fuel system set at 6.25 psi of fuel pressure. The ignition timing was set at 30 degrees with the MSD Digital 6 pulling 6 degrees when activated by the nitrous.

One of the benefits of using nitrous oxide is that hot ambient temperatures don’t affect the engine as much due to the cooling effect of nitrous oxide turning to a gas. On a steamy 96-degree Florida spring day, the first pass with the Edelbrock Performer RPM system clocked in at a 6.129 at 114.15 mph. The 60-foot time was 1.396 seconds, and the nitrous controller was set with 60 percent at launch and a 1-second ramp to 100 percent.

For the second pass we shortened the ramp to 0.8 second, and the short time came down to 1.368 seconds and e.t. dropped to 6.091 seconds at 113.33 mph. Opting to add a bit more at the hit next and see if the track could handle it, we went with 70 percent at launch with the same 0.8-second ramp, and our elapsed time continued to fall to a 6.009 at 115 mph with a 1.361 60-foot time.

With the Orlando Speed World crew staying on top of the track surface prep, we upped the launch to 80 percent and shortened the ramp to just 0.5 second. The 60-foot time came up at 1.326 seconds, and the eighth-mile clocks showed a 5.975 at 114.68 mph—running it out the back door of the quarter-mile showed a 9.41 at 141.82 mph. On a follow-up run a few weeks later the Mustang charged to a 1.28 60-foot time and a 5.897 at 114.24 mph.

Overall, the naturally aspirated Fox-body shaved off 1.3 seconds in elapsed time on a 175 shot of nitrous oxide. We also demonstrated how to improve performance using the nitrous controller, and it will come in very handy when track conditions are not ideal or perhaps in a no-prep drag race scenario.