Michael Galimi
September 12, 2005

Adding nitrous is the easiest way to get ahead of the competition in your Mustang. After all, the stuff is cheap and most systems are fairly simple to install. But making the decision of adding the juice leads to a whole slew of options. The biggest choice is the type of delivery system. There are a variety of ways to get nitrous oxide into your engine--from plate systems to single nozzles in the throttle body to direct port injection and even hidden systems. We won't even start talking about wet and dry setups either. The fact is, there are countless types of nitrous systems on the market to suit everyone's requirements.

This month we are going to tackle the installation of a direct-port nozzle nitrous system. In some respects, it is considered the most complicated to install, but the benefits far outweigh the complexity. Essentially this nitrous system has a nozzle in each runner of the intake manifold. The nozzle sprays a nitrous/fuel mixture into each intake port. As in all juice systems, jets are used to tailor the amount of fuel and nitrous going into the engine.

A lot of people shy away from direct-port injection due to the required "plumbing" to install it on their intake manifold. We hooked up with Steve Johnson, director of motorsports at Edelbrock, to plumb our intake. As Edelbrock's in-house nitrous guru, he deals with the top nitrous teams around the country. This former Pro Mod competitor can be found at almost every big Mustang and Street Legal race as an on-site Edelbrock tech rep. He offered to lend us a hand installing an Edelbrock Super Victor direct-port nitrous kit.

This is what 400 hp worth of nitrous oxide looks like coming out of the intake runners. The fuel side of the Edelbrock Super Victor direct-port nitrous system was not activated in this photo. This system can deliver up to a 500hp increase in power.
The Super Victor includes a lot of little parts, and the installation can be intimidating. We relied on nitrous guru Steve Johnson of Edelbrock to plumb this system on one of the company's Victor Jr. intake manifolds.
In just one day we took an Edelbrock Victor Jr. intake and made it into a serious piece.
All the lines, solenoids, and other equipment are designed to deliver nitrous and fuel to these babies. The nitrous and fuel are sprayed into the intake tract via these nozzles. There is one nozzle per intake runner.
Solenoids are the on and off valves in a nitrous system. On the left is the nitrous solenoid and on the right is the one for fuel. To avoid disaster, it is recommended that a wide-open throttle switch be used to activate the solenoids.
Johnson suggested blowing out and inspecting all the lines and nozzles to clear any packing material or leftover shavings from the manufacturing process.
Victor Jr. and Super Victor intake manifolds come with bungs on the runner that are designed for direct-port nitrous systems. We machined off the top of the bung and drilled and tapped each hole.

"A major benefit with this type of system is tunability per cylinder," Johnson says. "The fact that you can jet per cylinder and control how much fuel and nitrous go into each--that is quite a benefit."

For example, on some engines the front cylinders require a bit more fuel than the middle ones. This is an inherent problem in some race-style, small-block Ford motors. A larger jet can be used to compensate for this lean condition in a particular cylinder.

"I recommend getting a direct-port nozzle setup when shooting 250 (horsepower) and above," Johnson says. "That is when distribution starts to change." Of course, some racing sanctions require the use of a plate-type delivery system, but use a nozzle setup whenever possible. As the horsepower levels go higher in other delivery systems, the efficiency and distribution decrease. With a nozzle system, a specific mixture is set in each nozzle to ensure all cylinders work properly.

Screw on the two stainless steel tubes to the nozzle. Start with the middle, inside ones and work your way out.
After all eight nozzles are screwed into place, Johnson bolts on a Pro Systems 4150-style carburetor and CSI throttle cable bracket. We recommend using your exact setup so there won't be any clearance issues with the nitrous system when you go to hook up everything.
Screw on the two stainless steel tubes to the nozzle. Start with the middle, inside ones and work your way out.
Use a tube bender to bend the two pipes toward the middle. Keep an eye on the throttle cable bracket clearance and use the distribu-tion block as a guide. This will set the tone for the outside set of nozzles and the fuel part of the installation. Use a marker to mark where the tubes will screw on to the block.
Put high-pressure Loctite on the brass fittings when screwing them to the distribution block.
Once the tubes are marked, use a tube cutter to trim off the excess tubing. You will need to slide on a brass fitting and flare the end of the tube.

It is true the direct-port system can be intimidating due to nozzles and tubing running everywhere. But Johnson performs his magic on a lot of intake manifolds each week. He has done nozzle installations on intakes for Pro 5.0 cars down to daily drivers. For this project, he installed the single-stage setup on an Edelbrock Victor Jr. intake manifold designed for a 9.5-inch-deck engine. This intake did not find its way onto an engine yet, but the looks alone scream badass.

A direct-port nitrous system uses two distribution blocks on each side of the intake to deliver nitrous and fuel. Basically the fuel line is split at the fuel regulator to feed each fuel block. The nitrous works the same way, with a single line coming from the bottle and then a Y-block splits it off to either side of the manifold. Those distribution blocks then feed the lines that go to the nozzles. It all makes for a science project-looking type of system.

We recommend you do not plumb the intake while it is still on your engine. This should be done on a workbench. Nelson Competition Engines machined the bungs (which are already cast into the runners from Edelbrock) and drilled and tapped the holes for each nozzle. Johnson bolted on a Pro Systems 4150-style carburetor, valve cover templates, and a CSI throttle cable bracket to simulate a real-world installation. He has several carburetors and throttle cable brackets so he can re-create a customer's actual setup. That way, there are no clearance issues with the nitrous system.

The installation went smoothly, and when Johnson was done plumbing the manifold, he flow tested it on his custom nitrous flow bench. "We are not looking for a specific number each time," Johnson says, "but rather ensuring everything works properly and there are no leaks. Every manifold I plumb gets wet-flow tested and measured. You would be amazed at what is found with this process."

Simply attach the distribution block to the tubes. Repeat the process of measuring and cutting of the tubes for the outside set of nozzles.
Pictured here is the fuel block plumbed to the center set of nozzles.
Screw the fittings into the solenoids--the blue ones (A) are for nitrous and the red ones (B) are for fuel. The screens are used to keep debris out of the solenoids and nozzles as the small orifices clog easily.
Here is the entire system plumbed on both sides of the manifold. Using the throttle cable bracket and carburetor helped us install this system without worrying about clearance issues once hooked up in the car.

While we installed only a single-stage system, the intake can easily handle a second set of nozzles that can be used for a second stage. If someone wants to get creative, even a third kit can be fitted underneath the runners. Running three stages of juice gets a bit hairy on a small-block combination, but it has been done before and is usually used as the last resort in the final round.

Jetting is simple, and Edelbrock provides baseline tune-ups that are safe and designed to work in a variety of applications. Of course, it is up to the users if they want to fine-tune the system with fuel pressure and jetting arrangements. Be sure to keep an eye on your spark plugs when tuning to your particular engine.

The spark plugs are the window into your engine and will tell you if the system is running rich or lean. Make a pass down the dragstrip and shut the car off after the run. If possible, tow back to the pits for accurate reading of the plugs. We can write an entire book about reading sparks--just remember, white is lean and a brownish color is rich. If the tips are burnt off, then you have some problems.

When your engine is ready to handle a big load of juice, check out the Super Victor. It can increase your engine's output dramatically.

Tiny jets are used to regulate the amount of nitrous and fuel going into the engine. They are installed in each nozzle, making it a time-consuming process considering you have to change 16 jets. Johnson recommends checking all your jets with a pin gauge to ensure the orifice is properly sized. Edelbrock jets are stainless steel, whereas most companies use brass ones.
This is where the jets are installed--on the topside of the nozzle. We took this picture after the nitrous flow test as evident by the frost. Nitrous' cold nature is where the ideology of making your own atmosphere comes from.
This is what 950 psi of nitrous oxide looks like when exiting the intake. We flowed the nitrous and fuel side of the system separately. Normally the fuel and nitrous would be mixing when they leave the nozzle tip. That is called atomization.
These two gauges are what Johnson uses to ensure the system is working properly. The above photo is an oversized fuel-pressure gauge that is extremely accurate. The gauge on the right is used to measure fuel-flow rate.
Here are the three nozzles currently in Edelbrock's line-up. On the left is the E3 nozzle. Made of titanium, it is what most Pro Mod racers rely on. The E3 uses what is called a straight shot--the nitrous and fuel come directly out of the bottom. These nozzles are installed pointing straight down in the intake runner. The E2 (middle) and E1 (right) use the traditional 90-degree spray pattern. The fuel comes out the slit and the nitrous is sprayed out of the hole. We used the E2 nozzles in this installation. Each nozzle was designed for different applications.