In this comparison, the GT500...
In this comparison, the GT500 throttle body and adapter plate when installed on the factory intake manifold equipped with CMCV delete plates increased peak power from 410.96 to 414.65, for a gain of 3.7 horsepower-though we saw as much as 6 horsepower at just under 6,600 rpm. Out of curiosity, and because we had the parts, we reinstalled the stock CMCV plates with the GT500 throttle body throttle body, and the engine produced 409.08 and 411.28 hp on back to back pulls, thus showing that they are a restriction once the throttle body has been opened up.
In noting the aluminum construction of the C&L intake manifold, we asked Bender why he opted for this material versus the factory plastic composite. "Composite manifolds are ideal for OEM automotive manufacturers, as they offer a very low-cost product when you're creating very high volumes of manifolds," says Bender. "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.
"Composite tooling is created from 3D CAD models in software. Once the tooling has been cut, it may be necessary to completely redo it if you 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 as 'rapid prototypes' first, 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."
Finally, we bolted the C&L...
Finally, we bolted the C&L intake manifold on with the GT500 throttle body. Peak power improved to 429 horsepower, and adding a single-blade throttle body improved performance further to 435.90. The C&L piece really flows some air, so the better throttle body is going to be needed to make sure it lives up to its potential. In other areas under the curve, the single-blade was good for as much as 8 to 9 rear-wheel horsepower.
For a suitable test subject, we turned to Hurricane Performance in Orange Park, Florida, which offered up the company's '05 Mustang GT shop vehicle. The Mustang in question 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 that are used. Because C&L has eliminated the charge motion control valves (CMCV) from the intake tract, it uses slightly shorter bolts, which are provided. Total installation time was easily under an hour, and rather than just offering you a simple before and after test, we took the opportunity to run a few tests with different throttle bodies on both the stock and the C&L intake manifold.
C&L also opted to remove the...
C&L also opted to remove the center divider that the factory manifold incorporates. It also requires it's own unique gasket for the throttle body.
With a stock intake manifold, stock throttle body, and the factory charge motion control valves in place, the 5.0L laid down 409.08 rwhp, followed by 410.96 with the CMCV-delete plates. Next we installed a production GT500 throttle body and adapter plate, leaving the CMCV-delete plates on. Peak power increased from 410.96 to 414.65 for a gain of 3.7 hp-though we saw as much as 6 hp at just under 6,600 rpm. Out of curiosity, we reinstalled the stock CMCV plates, and power output decreased to 409.08 and 411.28 on back-to-back pulls. Once the throttle body has been opened up, they do become a restriction.
Next it was the C&L intake manifold's turn, and equipped with the GT500 throttle body, peak power improved to 429 hp. Bender told us that a single-blade throttle body wouldn't disappoint, and it didn't as it increased power output to 435.90. The C&L piece really flows some air, so the better throttle body is needed to make sure it lives up to its potential. While the single was worth some 7 hp at peak power, in other areas under the curve, it was good for as much as 8-9 rwhp.
In case you're addicted to...
In case you're addicted to nitrous oxide, C&L incorporated these bosses so you can plumb a direct-port nitrous oxide system.
Old drag racing habits die hard, so for the next dyno pull, we gave the engine a 45-minute cool down and iced the intake manifold for about 30 minutes. Horsepower increased from 435.90 to 442.58 at peak, and was up everywhere along the curve as well.
In the end, peak power went from 409.08 to 435.90 hp. The biggest improvement, however, was achieved at 6,875 rpm, where power went from 399.13 to 440.73, a gain of 41.6 hp. Since this test, C&L, Hurricane Performance, and TunersInc have swapped out the single-blade throttle body for the Ford Racing Performance Parts twin-bore Cobra Jet throttle body, and horsepower was within one single horse. What's more important is that driveability is much improved, and little to no tuning is required for it. C&L is now recommending the CJ throttle body for all of its manifold buyers.
Since the C&L intake does...
Since the C&L intake does away with the factory CMCV plates, it requires a different length intake manifold bolt, which comes with the intake when you buy it.
Further cementing the C&L intake manifold's impressive gains is the fact that NMRA Real Street competitor Tim Matherly will be running the intake manifold this year on his new Three-Valve combination, and S.D. Wheeler will be using one as well on his NMRA Super Stang entry as well. We expect to see even more out there now, considering C&L says it has sold its entire first run of manifolds already.
To fit the new intake on the...
To fit the new intake on the car, you'll need to slightly bend the alternator bracket for clearance.
Clearance between the bottom...
Clearance between the bottom of the intake and the alternator case was too tight for our liking, so we milled the case just a bit. C&L tells us this has already been resolved on future production pieces.
From left to right, you have...
From left to right, you have the Whipple single blade throttle body, the Shelby GT500 throttle body, and the factory throttle body. The GT500 and single-blade both improved power output.
With the intake bolted down,...
With the intake bolted down, you can replace the fuel rails and injectors. C&L took great care in making sure that the injector holes were just the right size, as they tell us that Ford uses a slightly different O-ring than on previous engines.
Despite the weight increase,...
Despite the weight increase, the aluminum does offer the benefit of heat reduction through the use of ice. This old trick worked just like it always has.
Going for broke, we gave the...
Going for broke, we gave the engine a 45-minute cool down and iced the intake manifold for about 30 minutes as well. In a drag situation, there's definitely power to be had using these methods. Power was up everywhere across the powerband.
Here we compare the factory...
Here we compare the factory intake manifold with stock throttle body versus the final C&L intake manifold with the single-blade throttle body, which had the benefit of a cool-down period with ice on the intake manifold for 30 minutes. Peak numbers went from 409.08 all the way up to 442.58 hp. The biggest gain, however, was achieved at 6,875 rpm, where power went from 399.13 to 440.73, a gain of 41.6 hp. The best "full hot" pull (without the aid of a cool down) delivered a still-impressive 435.9 peak horsepower reading. On this heavily modified Three-Valve engine, the C&L intake manifold proved to be a potent performer, without giving up much at the bottom end. With the car built for drag racing, it's optimized to benefit from the improvements made here as well.