Richard Holdener
March 29, 2010

If you own an '05-up Mustang GT, chances are you've been looking into ways to make it faster.

Sure, there are always the minor mods, which most of us choose strictly from a cost standpoint. Things like cold-air intakes, programming, and even headers or exhaust mods all yield decent performance gains. The problem is, unlike the previous Two-Valve motor, the Three-Valve is in such a higher state of tune that big power gains are not going to come from simple bolt-ons. You'll have to look at cams or changes in displacement to really make a difference.

The other option is to forgo natural aspiration and look into something a little more, shall we say, supernatural. We aren't talking about performance voodoo dolls or chicken sacrifices, but rather artificial aspiration.

It doesn't matter whether it comes from a bottle, a supercharger, or even a pair of turbos, adding power with supernatural aspiration will yield gains only dreamed of by the all-motor crowd.Rather than gains of 10, 20 or even 30 hp, boost and/or juice can yield gains of 100, 200, or even 300 hp. That my friends, is what supernatural is all about!

To illustrate the kind of gains available from supernatural aspiration, we took a stock 4.6L motor from an '05 Mustang GT and subjected it to both boost and juice.First up was a nitrous kit from Zex, followed by a Vortech supercharger. The final from of supernatural aspiration came from a twin-turbo kit from HP Performance in Roswell, New Mexico.

To ready the 4.6L for dyno use, we installed a set of JBA long-tube headers and a FAST management system, and swapped out the stock injectors for a set of 65-pounders, also from FAST.

It should be noted that the Three-Valve motors feature two electronic systems that make dyno testing difficult. The first is the electronic throttle, which we got around by converting to manual activation. Simple vice grips allowed us to create our very own drive-by-wire.

The last hurdle was the variable cam timing. Unfortunately, the FAST management system couldn't control the variable cam timing, so we were forced to run the cams in a locked position. This is not a big deal since all tests were run in the exact same configuration, but it would be nice to have the extra power offered by retarding the cam at higher engine speeds.

Run in stock trim with the long-tube headers, the 4.6L produced 361 hp at 5,800 rpm and 381 ft-lb of torque at 4,300 rpm.

Juice It!
We started our supernatural assault with chemical warfare. The history and make up of nitrous oxide has been covered in detail on numerous occasions-what you should know is that the important part of nitrous oxide is the oxygen it supplies. When nitrous oxide is injected, the chemical compound is broken down and releases the free oxygen molecules. Combined with additional fuel (to maintain the proper air/fuel ratio), the oxygen burns and produces exceptional power gains.

For our mod motor, we chose a wet EFI system from Zex. The Zex wet kit combines the nitrous and fuel into a single fogger, and injects that mixture into the throttle body. As with most kits, the amount of fuel, nitrous, and eventual power is controlled through jetting. For our test, we installed 150hp jetting, but made sure to optimize bottle pressure with a bottle heater.

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Adding the 150hp shot from the Zex nitrous kit increased the power output from 361hp and 381 lb-ft of torque to 510hp and a stump-pulling 562 lb-ft of torque. All this additional power came at the touch of a button. No wonder nitrous oxide is so popular.

Get Blown
What would any list of supernatural mods be without supercharging? Adding a supercharger to a Three-Valve is a no brainer, especially once you see how easy it is to make serious power.

For our test motor, we chose a blower kit from Vortech Engineering, but there are a number of kits available from a variety of sources. The Vortech kit features a reverse-rotation Si supercharger, but we elected not to run the intercooled system.

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