K&N OEM Replacement vs Intake?
 

I've been researching intakes and I'm struck by the fact that nobody seems to agree on which one is best. In fact, several tests have been posted showing the stock box actually ran cooler than most of the so called "cold air" intakes! Some people are also complaining of unpleasant noises including "mooing" while others seem to be perfectly happy and report only the normal swooshing or sucking sounds usually associated with intakes. In any case, this all has me confused and rethinking the K&N OEM replacement filter as an option. Any body have or had the K&N? Did you get a noticeable gain? Anybody gone from this filter to another intake? I know there are some fitment (word?)problems with it but it's looking better and better! Help!

stock is cooler
 

The stock, knightsports & PFS are the only one that are a true cold air or I should say ram/forced air. The Racing Beat peice opens up the restriction for more air but its extremely thin cheap material. The PFS intake works as a kit with the intercooler. I don't know enough on the knightsports to comment on it other than it's very expensive. If you have't bought an IC yet, the PFS is an excellent kit. The draw back is the same as stock. ONLY on idle, you can suck hot air from the IC but it won't be any different than an open filter IMO and is no more restrictive the the cold air boxes with tiny filters.

The cold air boxes are "not" cold air. They are colder air but certainly "not" forced/ram air!

* CWest makes a true ram air kit but that includes a new bumber with an hole to the air box (see attached pic).

Knightsports and Mazdaspeed may have something in the future by looking at the pics from the Tokyo auto show.

You can try RE-Amamaya head light kit
http://www.rotaryextreme.com/reamemi...dlightduct.jpg

I've got the stock air box with a K&N drop in filter. When I originally put the filter in about six or eight months ago, I really didn't notice much difference.

Just this past Saturday while I was cleaning the filter, I finally got around to cutting a hole in the bottom of the box. I also removed the foam from the passenger side of the radiator. I then fabricated a small duct with sheet metal to pull cold air from the space next to the radiator directly into the bottom of the air box. The result is a much stronger top end due to better secondary spool. I also now can sustain 10 lbs. of boost all the way to redline past 4500 RPM, instead of dropping back down to 8 lbs. like it used to.

Check the Robinette site for more in depth directions, or search the Forum for 'poor man's intake'. I'm very pleased with the results, and it will allow me to spend the money on other mods until I need an aftermarket intake to make room for an IC.

MBaltz do you have any pics of the job you did with the stock air box? I would like to see them, I have an aftermarket drop in filter for my third gen, I would like to do something different with my box to draw in more colder air.

I also tried several systems, but went back to the robinette method, because I felt it got me cooler air, also. I drilled about six 1" holes in bottom of box, and made a small duct under car to channel the air right to the holes. There still should be enough clearance and space in general to keep moisture away. When I finally have car painted, i'll then put my pettit system back on because I'll have a small scoop of some sort put in hood.

MBaltz

What is Robinette site?? Really want to check out the detail. Thx

anyone have any experience with ARC's intake box??

well i just thought that this post might help someone be creative and post up exactly what they did. If it works of course.

http://www.teamdelsol.com/howto/coldair/diycoldair.htm

If you have a FD, Robs site should be bookmarked!

http://www.rx7.org/Robinette/

i just have a pfs intake but took the cover and chucked it in the can!!! trust me those forced air intakes are not all there cracked up to be.my car runs better now that i removed the cover!! IMO.
here is a pic
thanx,ryan

I have the stock airbox with a K&N drop in. As everyone said not much difference until you open it up. After I put on the Racing Beat intake, the turbos spooled much faster and the butt dyno says it's faster. If you get the RB, just don't silicon it together. That makes it impossible to get off without breaking it. I needed to pull my off since the RB and K&N combo were giving me 13-14psi boost spikes and starting to make the stock intercooler come apart. I put on the RB intercooler straps and have been driving it this way for 1 1/2 years. The car pulls strong - I have no complaints.

Rikki
 

That's a med IC, but I was refering to the small smic kit from PFS. It has piping that connects to the air box from the IC duct and the air box has one large cone instead of two little ones.

Why don't you make a RAM CAI intake?
 

You can buy some 3" ducting from Kragen Auto ($9.99)and run the duct right to the front of the car either where the 2nd oil cooler is on the R1, if you have a touring and/or to the front just under passenger fog light. Just zip tie the ducts so that they can draw in the air coming straight at the car.

The 3" diameter ducts fit nicely between the body and the radiator gap(with some effort). I have two ducts connected right to my RE Amemiya intake. You can just run them to the bottom of the stock air box. I also made heat sheid for my RE Amemiya/Greddy intake to keep it from sucking in the hot air from the radiator.

Just my .02

John

I've got a K&N drop-in, with the modded stock air box, I love it! I can tell the difference over stock, I wouldn't say it is TREMENDOUSLY different, but it is noticeable.
One thing for sure, I have seen fuel cut-off at 12lbs. + of boost, in the cool, dense morning air you have to watch it! The car runs like a raped ape on these occasions, viciously spinning the tires on hard take offs (well, with the automatic the spinning tires take place about....20 yards past initial launch point!), and you can actually hear the rush of air into the box....glorious!

I have done the same mod and have some photos posted in the gallery at:

https://www.rx7club.com/photo/index....humb=1&cat=500


I too, like Bajaman enjoy improved primary spool-up (I also have an AUTO) and wheelspin 20 yards after launching and ability to hit primary & secondary boost cut (12+ psi ) on cold days.