I'm not sure if this info has been posted before, but I saw it on Brenspeed's website and thought it might be interesting to people. I didn't realize C&L is in the process of designing heads.
WHAT TO EXPECT FROM THIS PRODUCT:
1. The installation of this intake manifold is extremely easy and straightforward. No special tools are required and it is designed to utilize either the factory stock fuel rails or direct aftermarket replacement rails. C&L has confirmed the fitment of the "Fore Performance" fuel rails, and they will work on this intake manifold without issue, should you need them. They have gone through a great deal of effort to make every aspect of this product fit "perfectly", and this has helped to ensure that virtually anyone can install this product, provided that they follow the detailed supplied instructions.
2. Each runner on this intake manifold flows between 325 to 330 CFM each. This flow capacity is greater than ANY currently available cylinder head option for the 3V engine, which means that it will not pose a restriction to ANYONE at this point. C&L has an ALL-NEW aftermarket cylinder head design that they have been working on for some time, and sample castings have already been made. Once machining has been programmed for these new cylinder heads, the flow capacity is expected to approach (but not exceed) that of the C&L intake manifold's runners. Combined together as a "matched set", the minimum flow capacity per cylinder should be at least 320 CFM when air is flow tested through both the intake manifold and the intake port of the cylinder head together. This pairing will allow for higher levels of power than what has previously been achieved with built 3V engines.
3. Below 3,200 RPM, the performance of the new intake will be identical to, or slightly better than, the factory intake at wide open throttle accourding to C&L. Even though the CMVC flaps are not present, the high flow capacity of the intake manifold combined with runner length ensures that no power is lost below 3,400 RPM, which is the point at which the factory CMVC flaps open.
4. Power above 5,000 RPM will peak higher and maintain it's level all the way to redline (as shown the "after" dyno tests), while the factory intake manifold falls off sharply at 6,200 RPM. The gains over the factory intake manifold will be directly related to the power that the engine is generating. On a totally stock engine, the improvement over stock will fall in the 11 to 14 HP (max) range, but on more heavily modified engines with cams and ported heads, gains above 30 HP to as high as just over 40 HP are possible in the upper RPM range accourding to C&L. This means that average horsepower throughout your SHIFTING RPM will be superior to the factory intake design, which is exactly where you need it as you are going through the gears at wide open throttle. The "loss" of midrange power will have only minimal effect on your performance in the first gear that you are in when you go wide open throttle, but will have NO effect if your launch RPM is above this point.
5. From approximately 3,400 RPM to 4,800 RPM, there will be a midrange "loss" as opposed to the factory stock intake equipped with the factory charge motion flaps. This does not mean that there will be a "dip" in the power curve, but rather a lack of two "humps" that occurs with the factory intake manifold. The HP graph will still rise at a 45 degree angle with the new intake installed. At 3,400 RPM, the factory CMVC flaps open, which enhances midrange power through an increase in air velocity. This coupled with the manifold being tuned for power in the 4,000 to 5,500 RPM range causes two small "spikes" in the power curve. The elimination of the CMVC plates in conjunction with a shorter runner design causes the power curve to run "flat" (and straight) below these "humps".
6. The installation of a higher flowing throttle body will offer only modest (2 to 4 HP) gains on engines making less than 350 rear wheel HP, but gains of as much as 8 to 10 rear wheel HP on engines making closer to 400 rear wheel HP. Although "peak" horsepower is not improved my much in most applications, the installation of an aftermarket throttle body with our intake manifold minimizes the small midrange loss that occurs between 3,400 and 5,000 RPM.
7. The C&L 3V Manifold is cast from aluminum, and fully dressed it weighs just under 15 lbs more than the factory plastic intake manifold. If additional weight is of concern, then we recommend that you look into purchasing a Braille carbon fiber battery, which at under 10 pounds will MORE than offset the difference between the factory intake and our new assembly.
This product does require tuning.
All of the above tech data was provided by C&L and can be found on www.cnlperformance.com
C&L Intake Manifold Info 
