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 camshafts, and custom computer programming.
Rumors of its existence have been going around the Internet since the first prototype went out the door for testing. It wasn't long before the buzz turned into reality and the MM&FF staff received C&L Performance's first production intake manifold for the Three-Valve Mustang to flog on the dyno just for you, the reader.
Over the course of the last three years or so, C&L proprietor Lee Bender has been constantly refining the intake manifold to make sure it is the absolute best it can be.
"In 2003, we were the first company to develop an upgraded upper intake plenum for the '96-and-up Two-Valve 4.6L Mustangs, and that product was a huge success at the time," says C&L Performance's Lee Bender. "Our '05-and-newer products had 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 offerings that serious enthusiasts were using." Though the factory plastic intake manifold saves weight, Bender felt its plastic construction wasn't ideal for high levels of nitrous oxide.
"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 to 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 is also 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 of 2007," says Bender. "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 was 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 first cast samples were created nearly a year ago, and the first true production samples (with a revised intake port runner) were cast in July of 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.
1 Prior to testing the new...
1 Prior to testing the new C&L intake manifold, we opted to do perform some comparisons using the factory throttlebody and charge motion control valve plates, as well as this GT500 throttlebody, spacer, and CMCV delete plates.
2 After baseline testing...
2 After baseline testing with the stock manifold, it was time to begin the removal and replacement procedure, which starts with disconnecting the TPS sensor.
3 The throttle control harness...
3 The throttle control harness is next.
4 The fuel rails are then...
4 The fuel rails are then removed and will be reinstalled on the new intake.
5 The fuel pressure sensor...
5 The fuel pressure sensor is now disconnected.
6 The factory intake manifold...
6 The factory intake manifold rubber gaskets are reused with the C&L intake.
7 Now you can unbolt the...
7 Now you can unbolt the factory manifold.
8 The modular engine family...
8 The modular engine family certainly benefits from the rubber reusable gaskets, and makes changing parts quite easy for the enthusiast.
9 At first glance, the intake...
9 At first glance, the intake manifolds look similar, but there is quite a difference in runner design. For your benefit, we weighed the two intake manifolds. The factory composite manifold with the stock CMCV plates and throttle body weighs 20 pounds, 11 ounces. The same manifold/throttlebody with the CMCV delete plates dropped to 19 pounds, 8 ounces. The C&L intake alone weighs in at 32 pounds, 4 ounces, and 35 pounds, 8 ounces with the single-blade throttlebody.