Once you go supernatural,...
Once you go supernatural, you'll never go back....
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.
.....Nothing can compare to...
.....Nothing can compare to the power gains....
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!
....offered by nitrous, a...
....offered by nitrous, a blower, or a pair of turbos.
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.
The Three-Valve configuration...
The Three-Valve configuration flows significantly better than the older Two-Valve, and nearly as well as the Four-Valve Cobra.
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.
Ford offered a second trick...
Ford offered a second trick on the Three-Valve configuration in the form of variable cam timing. Advancing and retarding the cam timing (during operation) can have a positive effect on power and driveability over a broad rpm/load range.
Early Three-Valve motors featured...
Early Three-Valve motors featured extended spark plugs (right) that differed greatly from the plugs used on current modular motors.
The factory intake manifold...
The factory intake manifold (shown) on the Three-Valve is an exceptional piece, but the new unit from FRPP will be a great bolt-on replacement worth 20-50 hp depending on your application.
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.
To run the electronically...
To run the electronically controlled throttle on the engine dyno, we had to fabricate our own "drive-by-wire."
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.
Run on the engine dyno with...
Run on the engine dyno with long-tube headers, the naturally aspirated 4.6L produced 361 hp at 5,800 rpm and 381 ft-lb at 4,300 rpm.
We relied on a FAST engine...
We relied on a FAST engine management system to control the air/fuel and timing, though we did not have control of the variable cam timing.
The first in our series of...
The first in our series of supernatural upgrades was a Zex nitrous kit. The Zex universal wet EFI kit included everything needed to increase the power output of the mod motor by as much as 175 hp.
Nitrous and fuel delivery...
Nitrous and fuel delivery came by way of this fogger nozzle. Small jets determined the amount of fuel and nitrous (and therefore power) supplied to the motor.
The supercharger kit required installing the factory water pump (we ran a Meziere electric pump on the NA and Zex combinations), along with all the accessories. A single belt was employed to run the accessories, as well as the supercharger.
For our test, the fogger nozzle...
For our test, the fogger nozzle was installed in a rubber elbow positioned in front of the throttle body.
The Zex nitrous kit features...
The Zex nitrous kit features a dedicated controller that is capable of learning the WOT voltage from the TPS sensor. This safety feature ensures that the nitrous can only be injected under full throttle.
Equipped with jetting to supply...
Equipped with jetting to supply an additional 150 hp, the Zex nitrous kit increased the power output of the Three-Valve motor from 361 hp and 381 lb-ft to 510 hp and 562 lb-ft of torque.
Appropriately enough, item...
Appropriately enough, item number two on the list was supercharging. This kit for the Three-Valve came from Vortech Engineering.
The blower kit features a...
The blower kit features a discharge tube that directs the pressurized air from the round opening on the outlet of the supercharger to the oval opening in the factory throttle body.
Boost pressure from the supercharger...
Boost pressure from the supercharger is a function of blower speed relative to engine speed. Increasing the blower speed by changing to a smaller blower (or larger crank) pulley will result in higher boost and power levels.
Our previous fuel system upgrades would now come into play, as the supercharger was first configured to produce a peak boost pressure of 11 psi at 6,200 rpm. So equipped, the 4.6L produced 559 hp at 6,200 rpm and 513 lb-ft of torque at 5,300 rpm. A quick pulley change netted an increase in boost pressure to 13.7 psi, and with it an increase in peak power to 613 hp and 545 lb-ft of torque. Without the intercooler, that was about as far as we dared push the stock motor, despite the use of race fuel.
Run at the higher boost level, torque production exceeded 500 lb-ft from 4,200 to 6,200 rpm. All cranked up in intercooled form on an otherwise-stock Three-Valve motor, this same Vortech supercharger kit pushed the author to 192 mph in an '05 Mustang during a top speed test.
Run with the Vortech supercharger...
Run with the Vortech supercharger (non-intercooled) producing 11 psi, the 4.6L produced 559 hp at 6,200 rpm and 513 lb-ft at 5,300 rpm. Stepping the boost pressure up to 13.7 psi resulted in a jump to 613 hp and 545 lb-ft of torque.
Putting the final super in supernatural was a twin-turbo kit from HP Performance. The kit features a pair of 57mm Garrett turbos, a pair of Tial wastegates, and a pair of blow-off valves. Naturally, the turbo system was equipped with a front-mounted, air-to-air intercooler. When run on a Four-Valve Terminator crate motor, this same system produced nearly 1,000 hp at 20 psi of boost.
The turbo kit certainly had the power potential if you have the motor properly built to withstand the intended output. For our needs, we limited boost on this stock motor first to just 6.2 psi, then to 11 psi. The reason for limiting the boost pressure was that the motor produced so much torque that we began to fear for the strength of the internals.
The kit supplied features...
The kit supplied features a pair of 57mm Garrett turbos (enough to support over 1,000 hp) and produces 500 hp and 530 lb-ft of torque at just over 6 psi. Stepping up to 11 psi resulted in peak numbers of 624 hp at just 5,400 rpm and 664 lb-ft at 4,400 rpm. Torque production exceeded 600 lb-ft from 3,500 rpm to 5,400 rpm, making for one serious powerband.
HP Performance now offers an equally powerful single turbo kit for the '05-up Mustangs, as well as a full array of kits for 5.0L and modular Mustangs. Hellion Power Systems and a few others also offer suitable turbo kits.
On this stock 4.6L application, the twin turbos improved power output from 361 hp and 381 lb-ft to 500 hp and 530 lb-ft at just 6.2 psi. Imagine that-adding 140 hp with just 6 psi of boost.
The twin-turbo kit includes...
The twin-turbo kit includes a pair of dedicated tubular exhaust manifolds. Note the Jet Hot coating designed to maximize the all-important heat energy to the turbos.
Things really got serious once we upped the boost pressure to 11 psi, as the Three-Valve produced 624 hp and 664 lb-ft of torque. Torque production exceeded 600 lb-ft from 3,500 to 5,400 rpm, making this one serious torque monster. Even down at 3,000 rpm, the twin-turbo motor belted out 575 lb-ft of torque-so much for turbo lag!
The question now is not which form of supernatural aspiration is better, but which one works best for you?
Boost pressure is controlled...
Boost pressure is controlled by a pair of 40mm Tial wastegates.
Though we purposely kept the...
Though we purposely kept the boost pressure low on this stock motor, the HP kit features an ultra-efficient air-to-air intercooler.
Minimizing the build up of...
Minimizing the build up of boost pressure and helping to control compressor surge is a pair of bypass valves. These eliminate the pressure spike that can occur when shutting the throttle at high rpm/boost levels.
|Stock, 150hp Zex, Vortech (13.7 psi), HP Turbos (11 psi)|
|Stock, 150hp Zex, Vortech (13.7 psi), HP Turbos (11 psi)|