Muscle Mustangs & Fast Fords
Vortech V-3 SCi Supercharger Mustang 5.0L Engine Kit Upgrade
Adding A Supercharger To Your 5.0L Bullet Has Never Been Easier-Or Cheaper.
Another fuel system upgrade required was a swap to larger fuel injectors. Since Burcham is going to be tuning the system using a DiabloSport Delta chip, he elected to go right to a set of Ford Racing 60-pound fuel injectors. They might be overkill, but Burcham feels that while we are swapping injectors, we might as well go to a size that will be useful for many years-no matter what the combo is on the street.
The car was also equipped with a Pro-M 80mm MAF sensor, which was sent back to Pro-M for a new calibration to match the fuel injector size. Thanks to the massive 80mm size of the meter, we couldn't use Vortech's inlet tubing. That forced us to add a UPR inlet pipe, which places the meter in the fender and is a more efficient way to feed air to the supercharger. We were sure this molded plastic pipe was going to increase boost due to less restriction in front of the supercharger.
The car was equipped with an adjustable fuel pressure regulator, which we kept in place, along with the stock fuel rails. The fuel system upgrades were done because we elected not to use the Vortech-supplied FMU (fuel management unit). The UPR intake pump and Vortech T-Rex pump are more than enough to supply whatever we can throw at the engine-this is a stock short-block so we were limited to around 440-450 rwhp.
Essentially, the FMU is a secondary fuel-pressure regulator that increases fuel pressure based on boost. A vacuum line is run to the top of the FMU (which is installed on the return line), and a disk inside adjusts the fuel pressure based on boost. Adjustable fuel-pressure regulators increase pressure in a 1:1 ratio-1 psi of fuel pressure added for every 1 psi of boost. An FMU is set to a much higher rate than 1:1 for proper air/fuel ratio under boost (between 10.8:1 and 11.5:1).
The standard ratio in most Vortech applications is 12:1; meaning at 5 psi of boost the fuel pressure is spiked to 60 psi. If that pressure is increased to 6 psi, then the resulting fuel pressure is 72 psi at the boost level. The FMU operates at levels above the base fuel pressure setting. Vortech has different ratios for injector sizes up to 42 pounds. An adjustable knob for the FMU is also offered, to help dial-in the fuel pressure using minor psi adjustments.
The standard FMU from Vortech is calibrated to operate with factory injectors, which are 19-pound injectors. We, however, stepped up to the massive 60-pound units-putting us out of range of the optional Vortech FMU disks. Burcham programmed a custom DiabloSport chip to dial-in the fuel and ignition timing. He programmed the chip for a target air/fuel ratio and removed timing to prevent pre-ignition under boost.
Burcham also wanted to ensure that our test subject was more than capable of handling the extra air and fuel. He upgraded the ignition system by adding a set of spark plugs that are one heat range colder than stock; an MSD coil, cap, and rotor; and finally, a set of MSD spark plugs. "It's always a good idea to upgrade the ignition system when adding a supercharger," commented Burcham.
Vortech includes an ignition retard box in its High Output kit, which adjusts the timing based on boost. It is a fixed curve, which reduces timing 1-5 degrees for every pound of boost. The base kit doesn't require the timing retard, and Vortech recommends dialing back the timing to 10 degrees (with the spout out) for this kit. Since our engine was modified, Burcham backed the timing down using the computer and subtracted it from total timing, not the reading at idle, with the spout out. The stock total timing is set at 26 degrees in the computer (10 degrees base reading), and our baseline in naturally aspirated had 30 degrees total (14 degrees). Burcham removed 4 degrees of timing to bring it down to 22 degrees total due to the expected 5-6 psi of boost.