Who's In The Cold Air Intake Club and What Do Ya Got?

[AndyA6]

Regarding the honeycomb/screen in front of the MAF, this should be there! Don't ask technical details but let's say it evens out flow and makes for better reading. A lot of knowledgeable people say so.

[tony_fury]

Even the after market makers add the screen in front of the MAF

Agency Power Cold Air Intake Porsche Boxster 986 98-04

[Iflylow]

Radium King, Thanks for breaking all the math down. It all makes more sense, as far as calculating airflow, etc.

Homeboy, it sounds like you're selling something. Not a bad thing, if you are. Let's see it!

I have used CAI's on my other cars, including Mustang, RX-7 and RX-8, with varying degrees of success. Honestly, one of the reasons was that is was an easy way to add something interesting to look at under the hood.
This isn't the case with the 986, since nobody is going to see it, and it already is somewhat a CAI.

Referring to high-end gain at the expense of low-end, I would have been interested while I was in Germany, driving the autobahn. In the states, I have to agree with the poster who said he has enough power to put him in jail any day.

Still interested, if there is something out there. The vivid racing product looks like it has potential.

[Homeboy981]

Originally Posted by Iflylow

Homeboy, it sounds like you're selling something. Not a bad thing, if you are. Let's see it!

Sorry @Iflylow. Only selling an idea that you CAN DO MORE with what you have. But, if you want to buy a home….I have those! Nice homes, NOT swamp land!

I was hoping to get posters THAT HAD CAIs to come forward and SHOW THEIR INTAKES. There are several members who have "done it themselves" (@Sparker, @Insite, @CarbonFiberNut, etc.). I know, I PM'd them about their designs. And there are really good ideas out there. The solution is usually an amalgamation of designs. That is what I am trying to accomplish…if I can help the next guy, great!

I DID design a Wind Deflector that WILL NOT FALL OUT, cannot be stolen, and is good at race speeds….did I sell it? Not one….I have decided to GIVE IT AWAY instead!


As I do not have time. I create a lot of things, such as HH2Go - a Hydrogen system for cars, used in CA and other countries. We were able to almost double gas mileage but were shut down by lawyers….since then I have not really tried to sell anything but homes.

I am on my third attempt to mold a fiberglass intake surround around my conical filter, for me. If it can help YOU, GREAT! I have ideas all the time, again not the smartest guy in the room, sometimes they work some times not.

Here are some that I uncovered….









And this is the Honeycomb Filter ($10) - and no I am NOT associated with the Mfr.


Hope that clears it up!

[Jaxonalden]

Homey, I love that carbon fiber set-up. I like the way you and King have explained flow rates. I've been saying the same thing and tried to show the restrictions in the OEM assembly. That's why I've gone to the EVO.

Just like anything else, shortest distance between two points is a straight line (and a whole lot less restrictive). The sound ain't so bad nether.

[The Radium King]

mine is similar to insites (second from bottom) but using a larger airbox (his is 70 mm output, mine 85 mm) and some different ducting; i'll get photos up in a bit.

i really like the cayman intake (last one) and think it is the simplest and cheapest to diy; as per my other posts about that approach, however, i am concerned about performance in the wet. i'd love to hear from someone who drove it through torrential rain and reported on the results.

the reduced air temps with the kokeln ram air duct boggle my mind. temp reduction can't be due to the ram air effect as you need to be going really fast before the speed of your car is pushing more air in there than the engine can suck (192 liters per sec. assume the ram air duct cross-sectional area is 2 cm x 10 cm = 20 square cms. 1 liter = 1000 cubic cms, so 192 liters/sec = 192,000 cubic cms/sec. divide by 20 square cms and you get a column of air 9,600 cms/sec long = 96 meters/sec = 215 mph before you are ramming any air in).

what i *think* might be going on is:

- porsche put the intake at a high pressure area on the side of the car.
- wheel wells tend to create high pressure areas at the top of the wheel well.
- car aerodynamics try to cause a negative pressure (suction) underneath the car to keep it stuck to the road.
- hot engine air is getting drawn out of the engine compartment by the suction, into the wheel wells and out the top into the intake.
- the koleln unit, given that it is directional, draws air from further forward on the car and, as a result, gets cooler air.

if that is what is going on then that is a very valid product. food for thought (too bad they are so goddamn expensive).

[Iflylow]

So, from your description, I take it the orange one is yours. I like it, I think I will try it.
A few questions: Did you form the silicone tubing, or is there somewhere to purchase it at the right size?
I don't see where the honeycomb is installed in relation to the MAF. Could you describe that in a little more detail?
Thanks!

[Topless]

Nice summary of the challenges in improving on the stock intake design Radium. From my rough calculation, a 2.5L 6cyl motor only requires a 2" ID intake to achieve max VE at redline so I don't have heartburn over the stock design. If I jumped to a 3.4L motor and exhaust I would certainly need to re-tune the intake. No well-tuned intake would be complete without a carefully placed helmholtz resonator to cancel the acoustic pressure wave that would otherwise certainly foul your MAF sensor readings. Bigger and smoother are just the tip of the iceberg in a performance-tuned intake design.

A useful resource for getting the math right:
Volumetric Efficiency (and the REAL factor: MASS AIRFLOW), by EPI Inc.

[jaykay]

I have often wondered about the helmholtz chamber on the 3.2 intake. It's basically an odd shaped divergent section. It's much different than an accumulator type appendage which is usually seen. Even an F1 exhaust system has this discrete volume arrangement; have a look at the 2.5 L intake chamber.
Perhaps it's just enough to give some positive effect

Sound wise I can't speculate as I now have a large 3.25" pipe and cayman TB....I have needed to stay at 3.00" to give any sort of feedback

Oh yeah this thing roars when you floor it on cam.....I feel like I am waking the dead!

Originally Posted by Topless

Nice summary of the challenges in improving on the stock intake design Radium. From my rough calculation, a 2.5L 6cyl motor only requires a 2" ID intake to achieve max VE at redline so I don't have heartburn over the stock design. If I jumped to a 3.4L motor and exhaust I would certainly need to re-tune the intake. No well-tuned intake would be complete without a carefully placed helmholtz resonator to cancel the acoustic pressure wave that would otherwise certainly foul your MAF sensor readings. Bigger and smoother are just the tip of the iceberg in a performance-tuned intake design.

A useful resource for getting the math right:
Volumetric Efficiency (and the REAL factor: MASS AIRFLOW), by EPI Inc.