Muscle Mustangs & Fast FordsHow To Engine
Direct Hit of Nitrous
Installing an Edelbrock Direct Port Nitrous System on a Victor Jr. intake manifold.
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.
"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.
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."
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.