Cold air intake hype or facts

I am new to this, I just bought a 2000 GT convertible. I am looking into buying a cold air kit, but I am not sure what to buy yet.

I am wondering why so many of the CAI kits are made of metal. I have been checking out the pics and comments about BBK, JLT, and a few others. These are made of metal. Metal transfers HEAT. Cold air = more power.

I have seen postings about the CAI units being quite warm to the touch, especially when in city driving situations.

I havent seen much posted about the phenolic plastics or composite units out there. Roush has one, but I have not seen any data on this. The K & N kit 57-2519-3 - K&N 57 Series FIPK, Performance Intake Kit looks to be made out of some type of plastic too. Plastic is a better insulator.

So, am I correct in thinking that heat is an issue here? Metal or Plastic?

I have read a few different postings on CAI units, some folks say that there is more air turbulence INSIDE the fender wells, stating that it would be better to use the "ram air style" that sits along side the engine bay.

Soooooooo, is plastic better? Is not using the fender well better?

Has anyone ever stepped up to the plate and done a head to head comparison on these popular parts?



Jess
 
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Can't really answer the question posed, but it's ridiculous IMO to think that any turbulance in the fenderwell is going to outweigh the benefit of getting colder denser air into the motor. On the old 5.0s we sometimes found that "clocking" the MAF would put it in a position that would allow more accurate readings. I personally like metal tubing because it looks better and seems like it'll last longer.

When you matt the throttle, I can't imagine that the air stays long enough in the tubing for heat transfer to be an issue.

Chris
 
you are better off to remove the air silencer and install a drop in K&N filter.

heat transfer doesnt matter b/c the air doesnt stay in long enough for it to pick up any heat. if you drink hot coffee through a cold metal straw could the coffee be cold?.................................................
 
I got a bbk fenderwell intake, Looks great and fits great. Only diffrence I noticed is its now harder to check and see if my air filter needs to be cleaned or changed. Imo If you want a little bling buy it but if I we're to do it again I wouldve just got the drop in filter, got the stuff for an oil change, and a good set of wiper blades with a gallon of the rain X washer fluid.
 
theoretically the plastic would be slightly better due to the increased temps of the engine bay.... but overall as stated above the air is in there for a limited amount of time. The ambient temperature would have a greater affect with regards to temperatures.

As for the turbulence - there is turbulence in the fender and the engine bay. In both places you are drawing already disturbed air from the collision of air molecules with the front of the car. Especially considering the tortuous path that air has to take to get to the air intake- it is definitely turbulent by the time it gets to the filter.

So theoretically the system that would produce the most power would be plastic (insulated) in the engine bay and pulling cooler air from the fender. But in the real world CAI / RAI systems only give a small gain and the gain from following these theoretically optimal solutions rarely pans out to be a significant. I wouldn't spend tons of money trying to optimize the intake side from bolt ons, the biggest gains from bolt ons are on the exhaust side.
 
Best bang for the buck is a K&N drop in filter replacement and air silencer removal.

I datalogged my IATs (intake air temperatures) a while back on my car at the drag strip with the setup posted above. At the lights, when I was brake standing on it, the IAT was about 25 degrees warmer than ambient, which makes sense because of all the heat under the hood, especially with my supercharger, as it produces a lot of heat. By the time I was rolling 15 mph, the IATs were less than 10 degrees above ambient. By the time I was going 25 mph, the IATs were at ambient temperature. Once you get rolling, the stock filter location does it's job and pulls in air from the outside.

So take it for what it's worth, but for me, getting 25 degree cooler intake temperatures for that 2 seconds that I'm running slower than 25 mph isn't worth the extra $150 I'd spend on a full cold air intake.

And all things considered, you won't gain more than 10 rwhp on a full setup anyway.
 
The only advantage that I can see in a CAI system would be larger diameter tubing (not sure how aftermarket CAI's compare to stock tubing diameters). The larger the tube, the more air that is able to flow into the motor, obviously. However, a stock heads/cams/TB/plenum motor isn't sucking in enough air to benefit larger diameter tubing.

An aftermarket CAI isn't going to draw in "cooler air", whether it's metallic or plastic. Once you mod the motor so that it gulps in more air volume, THEN I can see how a CAI -MIGHT- be beneficial.
 
cai

This is getting interesting. My car has a cat back, I havent been under it yet to see if it has an x pipe or even what brand the pipes are. I only have it a week, and its been a rainy week in Pennsylvania.

I do plan on some mild mods in the future, I like to upgrade when things need to be repaired or replaced. I am still trying to figure out if everything is stock, and if not, what I am looking to change.

Your input has been helpful. Thanks.

I think I will probably get the JLT anyway, it looks like a good place to start.

Jess
 
The factory intake is a "cold air intake" when the silencer is in place. Even without it there, the factory air box would still get a decent amount of cool air from the giant hole in the fender-well next to it.

Excluding the OE paper filter (which is easily replaced with a K&N (E-0945) if there's a problem in the factory setup it's the OE duct that runs from the backside of the MAF to the TB. The corrugations that allow for engine movement cause turbulence and the thing really necks down where it passes the passenger side shock tower.

The HP and torque gains going to an aftermarket intake aren't going to be huge on a N/A 2V. You are as likely to get more power from the car leaning out a bit due to the intake (and removal of the flow straightener screen that usually accompanies these things: The need to "clock" a MAF speaks to the uneven airflow through the MAF that can result.)

On a blower car things are somewhat different, especially if the blower is a positive-displacement (PD) type (like a twinscrew or a Roots-style.) Gains from reducing pressure drops in front of a PD blower can be impressive. Cobras and KB 2Vs (for instance) might get 10 or 15+ HP from a decent CAI over stock.

On a N/A car I'd expect maybe 5HP and, if it's your thing, a better under-hood sound and appearance.
 
I believe that the main benefit of CAI over stock is as stated above, that the tubing is less restrictive and allows air to flow more freely to the intake. Whether metal or Plastic, the tubing is going to be at the same temperature. So then there's heat transfer... The metal will transfer heat better, but air is a very bad conductor and it won't pick up a significant amount of heat on it's way through vs a plastic tube. In the end, I think cold air intakes are worth it and while technically plastic will be ever so slightly better, pick the intake you think looks best to you in your price range and have at it.