Pete Epple Technical Editor
March 5, 2012

There is no question that the DOHC 5.0L Coyote engine has taken Mustang performance to new levels, and the spotlight, but if you have a Three-Valve 4.6L, there are still a lot of performance options available to increase the fun factor. Ported heads, larger camshafts, and boost can all take you to the next level—but even with an intake manifold as efficient as the stock one, performance can be limited.

Since it's introduction in the Mustang in the '05 model year, the Three-Valve 4.6L has had an amazing amount of support from the aftermarket. During its infancy, new parts seemingly hit the market every day. Among the slew of appearance upgrades and basic bolt-on performance parts, some hardcore go-fast goodies were designed and manufactured for those looking to go quicker and faster than most Mustang owners.

C&L Performance, Ford Racing Performance Parts, and JPC Racing each released an aftermarket intake manifold for Three-Valve Mustang engine. The designs are different, but the goal is the same—more power. The intakes are now within $200 of each other, but how do they perform? This month we are going to test each one on a naturally aspirated Three-Valve so you can see the results. Next month we will bring you the same test on a supercharged Three-Valve so you can see how horsepower is affected with boost.

The Subject— Blow-By Racing's '05 Mustang GT
For our Three-Valve intake test, we headed to Blow-By Racing in Boca Raton, Florida. One of the company's shop cars is an '05 GT with ported heads and aggressive camshafts, which makes it a perfect candidate for our test. Consistency for the test was extremely important, so each test was performed with air temperatures in the shop between 80 and 83 degrees, 195-degree water temperature, and a consistent 30 degrees of ignition timing, which seemed to be the sweet spot for each manifold. The testing was done on a Dynojet 224 chassis dyno.

All vitals, including timing, water temp, and cam timing were monitored using the SCT Live Link data logging software. All of the horsepower numbers are shown using the SAE correction factor, and the multiplier was the same 0.98 for each run. We used a Ford Racing Performance Parts throttle body (PN M-9926-3V) and a JLT Performance cold-air intake (PN CAI3-FMG05) as a constant for all testing.

With the stock intake manifold, our test subject laid down 367 rwhp and 307 lb-ft of torque. All of our intakes will be compared to these numbers.

C&L Performance - PN 720
Lee Bender of C&L Performance in Huntsville, Alabama, works hard to stay on the cutting edge of induction technology. When Ford introduced the Three-Valve 4.6L powerplant, Bender began designing an intake manifold to meet the needs of the Mustang hot rodders.

"We (C&L Performance) have spent four years developing this intake manifold,” explains Lee Bender, owner of C&L Performance. "The first flow testing for our original production runner designs took place in May 2007. The manifold has gone through two completely different sets of tooling and two different runner configurations since the original design.

"The last seven months of the product development cycle were spent optimizing various characteristics of the manifold with valuable help from independent third-party testing. We had to ensure the manifold's final configuration was flexible enough to support the needs of those with high-rpm engines, while also doing all that we could to maintain good overall performance for those who have cars that operate below 6,500 rpm.”

The C&L intake is a beefy piece. Its cast-aluminum construction, removable plenum cover (under side), and thick mating surfaces (cylinder head and throttle body) make it the heaviest in the group, but there are serious advantages to its design. C&L's cast intake will hold loads of boost, and has provisions for direct-port nitrous nozzles.

"By implementing individual port bosses for a direct-port system, our manifold allows enthusiasts to safely run as much nitrous as they are comfortable with, without fear of backfires, fuel accumulation, or fuel puddling issues,” adds Bender. He also tells us the intake can be iced at the track to chill the incoming air for additional power, although any gains will be seen for a very short period of time. The heat properties of a cast aluminum intake can also rob power when the intake becomes heatsoaked.

Installation was very easy. The stock O-ring-style gaskets get transferred from the stock ('05-'08) intake and the new manifold bolts into place. Once the temperatures were brought to the correct levels (manifold was allowed to cool to ambient temperature), the car was run on the dyno.

The final result was 375 rwhp and 318 lb-ft of torque, for a peak gain of 8 rwhp and 11 lb-ft of torque. Below 3,000 rpm, the C&L intake gained as much as 8 hp and 8 lb-ft, but the most impressive part is that it starts gaining hp at 4,200, and keeps gaining till you hit redline, with gains as big as 12 hp and 11 lb-ft through much of the second half of the graph.

C&L Performance
Cost $675
Material Cast aluminum
Weight 33.44 pounds
Runner Length 10.25 inches
Intake Volume 12.03 liters
Max Throttle Body Size Whipple mono-blade (GT)

Ford Racing Performance Parts PN M-9424-463V
When the phrase "bang for the buck” is thrown around, it's difficult not to think of the Ford Racing Performance Parts Three-Valve intake manifold. It is the least expensive manifold in our test, and the only one not constructed from cast aluminum.

"The Ford Racing Three-Valve intake manifold is constructed from composite plastic,” explains Jesse Kershaw of Ford Racing. "The composite offers a heat and weight advantage over aluminum intakes. When underhood temperatures go up, an aluminum intake will become heatsoaked and you lose horsepower and torque. The composite material used in the Ford Racing intake will not be affected the same way an aluminum intake would, so horsepower and torque are much more repeatable. The composite intake also weighs half compared to an aluminum intake.

"The Ford Racing intake gives you more plenum volume with shorter intake runners,” Kershaw adds. "The stock intake has about a 14-inch runner and the new intake's runners are 9.5 inches.”

A common misconception with composite intakes is its ability to stand up to boost. According to Kershaw, Ford Racing tested the new Three-Valve intake to 2.5-bar pressure or 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. This manifold would not be your best choice with high-boost or in applications where a lot of nitrous is being used. The chances of a composite intake surviving a nitrous backfire are slim.

Installation of the FRPP intake was a straightforward and easy. Everything needed to complete the installation, including a new fuel crossover hose, is included. On the dyno, heatsoak wasn't an issue. So once the engine was at temp, we began making pulls. The end result was 375 rwhp and 318 lb-ft of torque, netting FRPP a peak gain of 8 rwhp and 11 lb-ft of torque. Down low, the FRPP intake has small torque gains (2-3 lb-ft) until about 3,500 rpm, with little to no gain in horsepower. The effects of the shorter runners become apparent at about 4,100 rpm, and power and torque gains begin to slowly emerge, reaching its peak gain of 14 rwhp and 12 lb-ft at 6,000 rpm then tapering off slightly.

Ford Racing Performance Parts
Cost $599-$615
Material Composite plastic
Weight 11.30 pounds
Runner Length 9.5 inches
Intake Volume 11.80 liters
Max Throttle Body Size Whipple mono-blade (GT)

JPC Racing PN 3V Cast Intake
JPC Racing has made a name for itself on dragstrips across America. Justin Burcham, owner of JPC Racing, has put together some radical combination, pushing the limits of Mustang performance, especially in the modular segment.

"We designed the intake back in 2005 to fill a void in the market,” explains Burcham. "We wanted a big open plenum with shorter runners. It made good power through all of our testing, so we put it into production.”

In the early days, JPC constructed its manifolds from sheetmetal. The end result was an intake that made good power and extended the usable rpm range, but wasn't budget oriented. To combat the cost of machining, JPC went to work altering the manufacturing process, and now its intake is available in cast aluminum.

"The design change was based around price,” says Burcham. The sheetmetal intake works well, but it's expensive to build and takes a long time to assemble. The cast intake's design hasn't changed much from the original, but there are some cosmetic updates. A lot of the corners and edges are more round. The throttle body plate is billet and allows you to run a larger throttle body by simply switching the mount. We've also added a provision for an IAT sensor in the plenum. This is designed for centrifugal supercharged and turbocharged cars with the sensor in the MAF before the blower or turbo.”

Installing the intake was easy. The JPC piece was the only one in the test not using the O-ring-style gaskets. Paper gaskets are supplied with the intake and go between the intake and the cylinder heads. Once the installation was buttoned up, we were ready to move the rollers.

The cast version of the JPC intake laid down 381 rwhp and 316 lb-ft of torque for a peak gain of 14 hp and 9 lb-ft. The JPC intake's graph is slightly peakier than the graph with the stock intake. The JPC intake makes more power in the higher rpm range, but shows gains and losses in the low to mid-rpm range. At one point, the JPC is down by as much as 7 hp and 8 lb-ft, but a few hundred rpm later, it's up by 17 hp and 18 lb-ft.

The JPC Racing intake manifold was designed for high-rpm operation. It doesn't give up a lot of power and torque, but for optimal results it should be used with a combination that will see 6,500-plus rpm.

JPC Racing
Cost $795
Material Cast aluminum
Weight 22.30 pounds
Runner Length 8.12 inches
Intake Volume 8.30 liters
Max Throttle Body Size Whipple mono-blade (GT500)