Whether you choose boost or the bottle, the new 5.0L Ford offers plenty of performance.
Mustang owners were naturally excited about Ford's decision to introduce a new 5.0L, but the mod motor had some big shoes to fill. Despite concerns from enthusiasts about the advent of electronic fuel injection, the original 5.0L (introduced in the Mustang in 1986) ushered in a new era of Ford performance and was single-handedly responsible for starting a multi-million-dollar performance aftermarket catering to these vehicles. The modern iteration not only continues the tradition of the original, but steps things up considerably in terms of technology and performance. Limited in maximum displacement by 100mm (3.937 inches) bore spacing, the Coyote (an internal code that harkens back to AJ Foyt's team name while running a 4-valve Ford in the late '60s) team turned to technology to maximize performance while minimizing emissions. Their efforts paid off, as the new 5.0L outpowers the original by nearly 200 hp (412 hp and 390 lb-ft versus 225 hp and 300 lb-ft).
Though limited in displacement (3.623 bore, 3.653 stroke), the Coyote offers a specific output of 82.4 hp per liter (1.364 hp per inch), a number not equaled by Ford or Chevy on any of their normally aspirated V-8s. Credit for the impressive power numbers go to a combination of massive flow (nearly 300 cfm) from the 4-valve, aluminum heads. The overhead-cam design lends itself to impressive engine speed, though the peak power output of 412 hp comes at just 6500 rpm while the torque peak comes at 4250 rpm. This 2250-rpm spread between the horsepower and torque is a clear indication that the Coyote offers not just impressive peak power but a broad torque curve. By comparison, the horsepower and torque peak spread of the original (tuned for torque) 5.0L was just 1000 rpm.
Credit for the broad power curve goes to combining the massive head flow with variable cam timing. We all know that advancing a cam can yield low-speed torque improvements, while retarding them brings additional top-end power. Variable cams provide the best possible scenario, as the cams advance and retard to optimize power production through the entire rev range. This system is also used to provide passive EGR to enhance mileage and reduce emissions. Knowing boost and direct injection were in the cards at some point, the engineers saw fit to fortify the current Coyote for eventual forced-induction use.
Given the internal strength of the Coyote, we decide to test a pair of power-adders, namely nitrous and supercharging. The test motor came in the form of a 5.0L crate motor from Ford Racing (PN: M-6007-M50). Ford Racing was also kind enough to supply one of its Controls Packs (PN: M-6017-A504V) that included the remainder of the components required to get their crate motor up and running in a vehicle. The Controls Pack included a PCM, wiring harness, air intake system and even a drive-by-wire throttle pedal (necessary for the drive-by-wire throttle body used on the Coyote). The idea was to run the 5.0L Coyote in stock trim then subject it to boost and the bottle.
On the bottle side, we chose a Zex nitrous system designed specifically for the 2011 Mustang application. The Zex wet EFI system is adjustable from 75 hp to 125 hp. Given the elevated 11.0:1 compression ratio of the Coyote motor, we elected to hedge our bet and dose our 91-octane pump gas with a can of octane boost from Lucas Oil. We also employed SCT software and an X3 calibrator to load the files into the flash-only factory ECU. Per the instructions, we retarded the timing by 4 degrees after activation of the nitrous (timing changes required adjustments to no less than 32 different timing tables in the software).
To establish a baseline, we first ran the Ford Racing crate motor in stock trim with a set of headers from American Racing Headers and a Meziere electric water pump. Run with the factory air intake, the stock 5.0L Coyote produced 462 hp at 6600 rpm and 410 lb-ft of torque at 4400 rpm. After repeatable baseline runs, we installed the Zex nitrous system. The Zex kit featured a sophisticated control box capable of learning the TPS signal to ensure activation could only come at wide-open throttle. After heating the bottle to ensure adequate pressure (over 900 psi) and equipping the single fogger nozzle with jetting to supply an additional 75 hp, we activated the wet EFI system. The Zex nitrous increased the power output of the Coyote motor from 462 hp and 410 lb-ft of torque to 554 hp and 540 lb-ft of torque. Despite jetting for 75 hp, the Zex system improved the power output by 92 hp and 130 lb-ft of torque. Nothing offers the combination of power and price like a good nitrous system. The Zex had even more power to offer (jetting for another 50 hp), but we were anxious see some boost.
Designed for the 2011-up 5.0L Mustang, the Kenne Bell supercharger system is available with a 2.8L or massive 3.6L supercharger. Options include patented Liquid Cooling on the blower (not to be confused with air-to-water intercooling, which was standard on all kits), Seal Pressure Equalization, and H-series blowers for high-boost applications. Though enthusiasts migrate directly to the bigger blower, the reality is that the 2.8L is likely a better match for a stock 5.0L motor. Capable of supporting 1,000 hp, the 2.8L offered improved response at the lower boost and power levels typically run on an otherwise stock motor. If you're looking for 1,200 hp, then try the larger 3.6L, but if you want a blower for your stock 2011 'Stang, the 2.8L is really the hot set up. We chose the 2.8L for boosting our Coyote crate motor. As indicated, the Kenne Bell supercharger kit also included an efficient air-to-water intercooler, larger injectors and a range of different blower pulleys to adjust the boost pressure. Tested previously on a stock 5.0L Mustang, the standard supercharger kit improved the power output from 374 whp to 553 whp at 8 psi (using 91 octane) and 595 at 10 psi (using 94 octane).
We knew from experience that the Kenne Bell twin-screw supercharger offered exceptional performance and couldn't wait to boost our Coyote. The gang from Kenne Bell (Mike Decourcey and Ken Christley) were even on hand to help install the kit and load their dedicated tunes. Rather than simply install the blower and be done with it, we decided to take this opportunity to illustrate the airflow restrictions inherent in the factory induction system. After installation of the Kenne Bell blower assembly, we configured the supercharged 5.0L Coyote with the stock 80mm throttle body and air intake system. The Kenne Bell Mammoth intake was designed to accept a variety of different throttle bodies using an aluminum adapter plate. The blower was equipped with a 4.125-inch blower pulley that ultimately provided a peak boost pressure of 6.5 psi, falling off to just 6 psi at the power peak. The falling boost curve was a clear indication that a restriction was present. Equipped as such, the supercharged 5.0L produced 588 hp and 493 lb-ft of torque. Now it was time to remove the restrictions.
The factory air intake and throttle body were replaced by components supplied by Kenne Bell with its kit. The company included a dedicated cold air intake that consisted of a free-flowing cone filter feeding a massive 4.5-inch intake tube designed to accept the factory MAF electronics. The stock 80mm throttle body was ditched in favor of its 168mm oval throttle body that more than doubled the flow rate (967 cfm versus 2,150 cfm). These changes alone were worth 2.3 psi and nearly 80 hp. Combining them with a drop in pulley size (3.875 inches) to further increase the boost pressure to a peak of 9.9 psi resulted in an amazing 704 hp and 549 lb-ft of torque.
The air intake upgrades and pulley swap improved the power output by 116 hp and 56 lb-ft of torque. Given the Kenne Bell 2.8L was capable of supporting over 20 psi on this 5.0L, we had just scratched the surface of the potential of the supercharged combination at 9.9 psi. The great thing is that the Coyote will likely run all day long at just 9.9 psi of intercooled boost, and how do you argue with any 302-cubic-inch motor that pumps out more than 700 hp?
Even in stock trim, the new 5.0L Ford offered impressive power given the displacement. Run with long-tube headers, the Ford Racing Coyote produced 462 hp and 410 lb-ft of torque. Adding nitrous to the mix (with 75 hp jetting) increased the power output by nearly 100 hp to 554 hp and 540 lb-ft of torque. Nothing can compete with nitrous when it comes to bang for the buck. The power output really started to climb once we installed the Kenne Bell supercharger. Even restricted by the factory airbox and throttle body, the supercharged 5.0L pumped out 588 hp and 493 lb-ft of torque. Combining a blower pulley change with replacing the stock throttle body and induction boosted the peak power numbers to 704 hp and 549 lb-ft of torque at 9.9 psi.