Rumors of its existence have been going around the Internet since the first prototype went out the door for testing. Over the course of the last three years or so, C&L proprietor Lee Bender has been constantly refining his latest product to make sure it was the absolute best it could be. Finally, the Internet buzz turned into reality, and C&L Performance's first production intake manifold for the Three-Valve Mustang was ready to be flogged on the dyno.
"In 2003, we were the first company to develop an upgraded upper intake plenum for the '96-and-up Two-Valve 4.6L Mustang, and that product was a huge success at the time," says C&L Performance's Lee Bender. "Our '05-and-newer products quickly accounted for the highest percentage of our overall sales. This led us to evaluate the factory Three-Valve intake manifold to determine what improvements could be made. Although the factory intake does have a higher flow capacity than the stock cylinder-head intake-flow capacity, it still fell short of the CNC-ported heads that serious enthusiasts were using." While the factory plastic intake manifold saves weight, Bender believed its plastic construction wasn't ideal for high levels of nitrous oxide.
Though it looks like a mildly...
Though it looks like a mildly modified 4.6L engine, our test subject is quite a bit more. The 302-cube bullet packs a mean 409 rwhp thanks to the added displacement, ported and polished cylinder heads, a pair of hot AFM camshafts, and custom computer programming.
"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," notes Bender. "In our dyno testing, the manifold has shown that clear gains are afforded by the intake manifold on everything from a totally stock engine (11-14 hp) to a fully built engine. The better the heads flow and the higher the engine operating rpm, the greater the potential gains are with the new manifold design. It's a natural for high-boost applications as well."
Designing, testing and producing your own intake manifold is no easy feat-in fact it's a major undertaking.
"The first flow testing for our original production runner designs (for comparison with the original manifold capacity) took place in May 2007," says Bender. "The manifold has gone through two completely different sets of tooling and two different runner configurations since the original design.
The first test we performed...
The first test we performed utilized the stock intake manifold and throttle body, and the factory charge motion control valves (CMCV). We then installed the CMCV-delete plates for comparison. Despite the relatively high-horsepower nature of the engine, peak horsepower only increased from 409.08 to 410.96, and for the most part, power was left unchanged throughout the pull. In a couple of areas, gains of 2 to 3 hp were shown. For the average street car, they would not seem to be a cost-efficient horsepower upgrade, but on a max-effort naturally aspirated setup, every single horsepower counts.
"The last seven months of the product development cycle was spent optimizing various characteristics of the manifold with valuable help from independent third-party testing. We had to ensure that the manifold's final configuration was flexible enough to support the needs of those with high-rpm engines, while doing all that we could to maintain good overall performance for those who have cars that operate below 6,500 rpm. The first cast samples were created over a year ago, and the first true production samples (with a revised intake port runner) were cast in July 2009.
Getting down to specifics, we asked Bender what the main differences are between the C&L intake and the factory plastic piece.
"Aside from its aluminum construction, which is a substantially more durable material, it features an individual intake port flow capacity that is roughly 28 to 30 percent greater (on average) than the original intake," notes Bender. "This was accomplished by eliminating the crossover runner design of the factory manifold. By keeping the port entry location for each respective bank of runners away from the other, we were able to maintain the same port shape throughout the entire runner. The stock crossover manifold (due to front-to-rear-port length and spacing) has to convert the runner from a round opening to the oblong shape of the factory port at the cylinder head. The runners are length-tuned to develop a horsepower peak that starts at around 5,000 rpm and extends to at least 7,000 rpm, and even higher if the engine is built to operate above that range.
Prior to testing the new C&L...
Prior to testing the new C&L intake manifold, we opted to do perform some comparisons using the factory throttle body and charge motion control valve plates, as well as this GT500 throttle body, spacer, and CMCV-delete plates.
"The total manifold volume has been increased by 1.1 liters, which gave us the best overall performance at all rpm points during testing. The factory charge-motion-control valve plates are completely eliminated when installing this manifold, and this saves the customer the trouble of having to purchase aftermarket delete plates.
"Every major characteristic of the manifold was adjusted and thoroughly tested to ensure we had the best possible configuration. This testing, along with that of third parties using various configurations, added substantial time to the finalization of the product, but it also ensured we had done everything that we could to optimize the product."
After baseline testing with...
After baseline testing with the stock manifold, it was time to begin the removal and replacement procedure, which starts with disconnecting the TPS sensor.
The throttle control harness...
The throttle control harness is next.
The fuel rails are then removed...
The fuel rails are then removed and will be reinstalled on the new intake.
The fuel pressure sensor is...
The fuel pressure sensor is now disconnected.
The factory intake-manifold...
The factory intake-manifold rubber gaskets are reused with the C&L intake.
Now you can unbolt the factory...
Now you can unbolt the factory manifold.
The modular engine family...
The modular engine family certainly benefits from the reusable rubber gaskets, and it makes changing parts quite easy for the enthusiast.
At first glance the intake...
At first glance the intake manifolds look similar, but there is quite a difference in runner design between the two. For your benefit, we weighed the two intake manifolds. The factory composite manifold with the stock CMCV plates and throttle body weighed in at 20 pounds, 11 ounces, and the same manifold/throttle body with the CMCV-delete plates dropped a bit to 19 pounds, 8 ounces. The C&L intake alone weighs in at 32 pounds, 4 ounces; it weighs 35 pounds, 8 ounces with the single-blade throttle body.
As you can see, the C&L manifold...
As you can see, the C&L manifold was designed to eliminate the factory charge motion control plates.