Wes Duenkel
March 19, 2019
Photos By: Courtesy of Redline Motorsports

When building horsepower, the simplest route often saves time and money. When Matt Bell of Redline Motorsports wanted to supercharge his mildly-built 1993 Mustang GT, he saw an opportunity in Holley’s new Super Sniper 1250 throttle-body EFI system for blow-through supercharged applications.

Bell’s Fox-body already had an add-on EFI programmer and aftermarket ignition system overriding much of the factory’s ECU programming, and Bell thought adding a supercharger into the mix would only compound the tuning headaches. Not only does Holley’s Super Sniper EFI offer self-learning functions ease the tuning process, the self-contained ECU and plug-and-play ignition system greatly simplifies the wiring requirements. The Holley Sniper eliminates the mass air flow sensor and injector harness, as all the sensors, injectors, and idle control are incorporated into the Sniper throttle-body.

The Sniper blow-through, throttle-body utilizes a traditional carburetor intake, and Bell selected a Weiand Stealth dual-plane intake for a good balance between top-end power and torque. Combined with the efficiency of Vortech’s V-3 Si centrifugal supercharger, Bell was hoping to put more than 500 horsepower to the wheels.

Besides complicating the fueling situation, adding boost to a naturally aspirated application also requires retarding the ignition timing under boost to avoid detonation. Fortunately, Holley now offers a plug-and-play “HyperSpark” ignition system for their Sniper EFI systems. When used with a Holley HyperSpark distributor, the Sniper has full control of spark timing, eliminating the need for a separate programmable ignition system. Bell also used Holley’s 450 LPH In-Tank Retrofit Fuel Module and Holley Billet EFI Bypass fuel pressure regulator to make sure the 306-inch engine had plenty of fuel under boost.

The results were beyond satisfying. Bell’s 1993 Fox made 318rwhp with a typical head, cam, and intake combination. As an interim step, Bell dyno’d the naturally aspirated combination to compare the Holley Super Sniper 1250 and Weiand intake to the typical 5.0 EFI setup. The throttle-body injection configuration made 16 more horsepower and nearly identical peak torque, which surprised us considering how different the two intake manifolds look.

After adding 11 psi of peak boost with the Vortech V-3 Si blower, Bell’s 306ci picked up 173 horsepower and 129 lb-ft of torque for a total of 505.59 horsepower and 457.83 lb-ft of torque. Bell was more than pleased with the results. “This Vortech V-3 Si Blower is very efficient and we were able to surpass our horsepower goals utilizing the standard 3.33 pulley.”

Besides the power results, Bell did all the tuning utilizing the included handheld tuner. While laptop software is available, it wasn’t required to get this combination running and making great power. Besides the improved startup and drivability Holley Super Sniper and HyperSpark offered, Bell was impressed on how simple the Holley Super Sniper 1250 and HyperSpark Ignition was to install and set up on this supercharged combination. The Holley setup eliminated all the add-on workarounds normally required with a factory-style EFI system. This means an owner can install a supercharged EFI system and get their Mustang running without trailering the car to a specialized tuner.

1. Redline Motorsports put this forced induction conversion kit for Mustangs utilizing the Holley Super Sniper 1250 throttle body EFI system, HyperSpark ignition system and distributor, and a Weiand Stealth intake manifold.
2. Here’s a list of the major parts that Matt Bell and Redline Motorsports used convert the 1993 Mustang GT to a Vortech-supercharged, blow-through Holley Super Sniper combination.
3. Here’s where Redline Motorsports’ Matt Bell started: a DSS 306 short-block topped with AFR heads, Typhoon intake, 75mm throttle-body, exhaust, and a few other typical bolt-ons. Naturally aspirated, the combination made 318 horsepower at the wheels.
4. Redline Motorsports began by removing the mass air flow sensor (MAF). The Holley Super Sniper 1250 doesn’t use a MAF, so we set it aside.
5. Next, they removed the upper intake manifold.
6. Bell already deleted the air conditioning, so the Redline crew only had to remove the power steering pump on the left side.
7. Then, they removed the alternator bracket to make way for the Vortech supercharger.
8. To make way for the Weiand Stealth dual-plane intake manifold, they removed the Typhoon EFI lower intake manifold.
9. Next, it was time to install the Weiand Stealth intake manifold. This is the same type of manifold used when converting an EFI engine to carburetion.
10. The Redline Motorsports crew installed the Holley Super Sniper EFI throttle-body. Note that the Sniper throttle-body integrates the ECU, injectors, and many of the sensors needed to run the system into one part, greatly simplifying installation.
11. Next, they installed the Holley HyperSpark distributor.
12. Rather than top the Holley Super Sniper 1250 EFI throttle-body with an air cleaner, Bell chose Holley’s blow-through hat.
13. Next, the Redline Motorsports crew turned their attention to removing the factory EFI harness, as it won’t be needed with the Holley Super Sniper EFI system.
14. Since the Holley Super Sniper’s ECU is housed in the throttle-body, the factory ECU was removed.
15. Here’s the pile of parts that we didn’t need anymore. The Holley Super Sniper and HyperSpark system replaces all this with just a few key components.
16. To make room for more boost later on, Bell decided to forgo the Holley Super Sniper’s integrated fuel pressure regulator in favor of an external Holley Billet EFI Bypass fuel pressure regulator.
17. With the throttle-body and fuel pressure regulator installed, Bell built and connected the fuel supply and return lines.
18. Next, Bell swapped the throttle linkage to that of a 1979-1985 carbureted Mustang.
19. Then, the Redline Motorsports crew installed the supercharger bracket, remounted the alternator, and bolted up the Vortech V-3 blower.
20. To get the proper belt routing, they installed an A/C eliminator idler pulley and finished mounting the supercharger.
21. Next, they installed the discharge tubing for the supercharger.
22. Since the Holley HyperSpark ignition system includes an ignition amplifier, the old MSD box was removed.
23. Redline Motorsports mounted the Holley HyperSpark ignition box in place of the old MSD.
24. Holley’s HyperSpark ignition also included an ignition coil. Bell wanted to retain as many original parts as possible, so removed HyperSpark coil from its mount and used the factory coil mount instead.
25. Bell identified and utilized the factory fuel pump relay wire to activate the Holley fuel pump relay.
26. After installing the included wideband O2 in the exhaust and buttoning up the installation, this is how the engine looks with the Holley Super Sniper 1250, HyperSpark, and Vortech V-3 Si supercharger. (Note the RF noise blocking plate behind the distributor that Redline Motorsports devised to keep radio frequency noise from the distributor from interfering with the ECU in the throttle-body. Nice thinking!)
27. With everything up and running, it was off to the dyno for power pulls. Bell was impressed with the initial startup and drivability with the Super Sniper.
28. Bell did all of the initial setup and programing of the Holley Super Sniper 1250 EFI system with the included handheld device.
29. To satisfy Bell’s curiosity, he used Holley’s available laptop software to take a look “behind the scenes.” He was impressed how the Holley Super Sniper 1250 EFI system tuned itself using the included wideband O2 sensor to form a smooth and accurate fuel map. Bell suspects with more boost and cubic inches in this car’s future, the laptop tuning ability will come in handy.
30. Naturally aspirated, the Holley Super Sniper made 16 more horsepower and nearly identical peak torque to the old setup. After adding 11 PSI of peak boost with the Vortech blower, Bell’s 306 picked up 173 horsepower and 129 lb-ft of torque for a total of 505.59 horsepower and 457.83 lb-ft of torque.