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Three-Valve Intake Manifolds - Three's A Crowd
Part 2: Three intake manifolds for Three-Valve Mustangs with boost
Ford Racing Peformance Parts - PN M-9424-463V
Ford Racing Performance Parts has designed its Three-Valve intake manifold to be a great all-around performer at a great price. It was strong in our naturally aspirated test, and is the only composite intake in the group (other that the stock manifold). Its composite construction is great for beating heat soak issues. The downfall to this design is possible ballooning under high boost, and possible bursting in extreme combinations. According to Jesse Kershaw of FRPP, Ford Racing tested the Three-Valve intake to 2.5 bar pressure, or roughly 35 psi, and after some ballooning in the early development phases, the intake manifold has specific reinforced areas, which allow for extremely high boost levels. Even above this, the manifold will not burst. Instead, the gasket is designed to bleed off the boost and re-seal as the boost level drops. One could theoretically RTV the manifold together eliminating this "blow off" safety, but at over 30 psi, a sheet metal intake manifold might be a safer option
The intake was quickly swapped onto Gastright's GT. Jones made a baseline pull and after looking at the datalogs, he made changes to the timing and fuel curves to bring the air/fuel ratio as close to 11.7:1 (the air/fuel number used as the standard throughout the test), while making the most power as possible. When the tuning was complete, Jones made 659 rwhp and 557 lb-ft of torque for a peak gain of 14 rwhp and 14 lb-ft of torque with 18 degrees of timing.
At the start of the run, the FRPP intake showed slight gains (8hp and 7lb-ft of torque) over the stock unit, but power and torque were nearly identical from 3,400 to 4,700. At 4,700 rpm, the FRPP intake began to gain power and torque, quickly reaching the 14hp and 14 lb-ft gain, which it carried until the end of the pull. Its combination of runner length, plenum volume, and lightweight construction make it a great choice for anyone looking to add some power to their boosted Three-Valve.
JPC Racing PN 3V Cast Intake
The JPC Racing Three-Valve intake manifold was designed to benefit Mustang enthusiasts and racers looking to extend the S197's rpm range.
Although any intake manifold with runners shorter than stock should make more power in the higher rpm range, shorter runners can sacrifice power and torque at lower rpm. Justin Burcham of JPC designed this intake to be a balance of minimal low-rpm loss and maximum high-rpm gain.
Jones installed the JPC intake and began making changes to the tune. The baseline pull netted great numbers, and we were excited to see how high the horsepower numbers would be. When Jones reach max power, timing was at 19 degrees, and output was 672 rwhp and 588 lb-ft of torque, for a gain of 27 rwhp and 45 lb-ft of torque.
Given the short-runner design of the cast JPC Racing intake manifold, we expected it to show the biggest high-rpm gains, but we were impressed by how much power and torque picked up. Given its short runner length (just over 8 inches), we expected low-end power to be greatly reduced, and although the JPC intake lost as much as 13 hp and 25 lb-ft below 3,000 rpm, it was even or better than the stock intake from 3,200 rpm to redline. There is an exception of one spot where power dropped, but this could most likely be corrected in the tune.
If you race your Three-Valve Mustang and want to take advantage of high-rpm power potential, the JPC Racing Three-Valve intake manifold is the way to go.