C&L Performance's New Three-Valve Intake Manifold - Expand the Limits

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.

"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 ... 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 in order 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 that we had done everything that we could to optimize the product.

"Composite manifolds are ideal for OEM automotive manufacturers, as they offer a very low-cost product when you are creating very high volumes of manifolds. The up-front tooling costs are several times higher than what it costs to develop a mold for an aluminum product, but if the volume is there, the cost savings per unit can more than make up for it over time," says Bender. "Composite tooling is created from 3D CAD models in software; once the tooling has been cut, it may be necessary to completely re-do the tooling if you see the need to make a substantial revision or change to the product. This can become very costly, which is why most parts made in this manner are tested first as 'rapid prototypes' to evaluate and make adjustments until the product is right. Although these prototypes can be made rather quickly, they are quite expensive to create.

"We take a very hands-on approach to product design and development. Although 3D modeling is becoming more commonplace within our business, I still prefer to do most things by hand. In the performance aftermarket, the sales volume in most cases simply does not lend itself well to using composites for creating intake manifolds. The up-front tooling costs for aluminum castings may be less, but the time required to make revisions and adjustments is longer than with rapid prototyped parts."

For a suitable test subject, we turned to Hurricane Performance in Orange Park, Florida, which offered up its '05 Mustang GT shop vehicle. This Mustang is currently at the pinnacle of 4.6L, Three-Valve performance with its naturally aspirated 400-plus-rwhp status, and we thought the C&L intake manifold would give it a sizeable kick in the pants over the factory intake manifold. The Mustang features an Al Papitto-built (Boss 330 Racing) 302ci bullet based on a Ford Racing Performance Parts Boss 302 block. Kris Starnes ported and polished the stock heads, and a pair of Anderson Ford Motorsport prototype camshafts moves the air and fuel through the engine.

Installation of the C&L intake is fairly simple. The only real change between it and the stocker is the length of the bolts. Because C&L has eliminated the charge motion control valves from the intake tract, it uses slightly shorter bolts, which are provided. Total installation time was easily under an hour. Rather than offer a simple before and after test, we took the opportunity to run a few tests with different throttlebodies on both the stock and the C&L intake manifold. We were pretty pleased with the results on our naturally aspirated test subject, and we're eager to see what it will do on a supercharged or turbocharged application. MP