ooops. my fault, i failed to notice he was talking about 2nd gen sedans.

yea, I read some posts about people losing power with R2Cs, but it was something about filter.... Not too sure, should go around and pm those pple if you want accurate info

And as for why colder air is better, what Anton said
Colder air is more dense and is capable of holding more molecules in contact, thus allowing more Oxygen to be sucked into the intakes. However, it also depends on the environment as its not only limited to oxygen that's in the "air", where nitrogen and other components are found. The absolute percentage of the oxygen may not change (although more oxygen molecules WILL be sucked in, and allow higher combustion)

Injen!

I agree. I had the JWT Pop and it sounds soooo fkn cool but I ended up going back to Z tube and KN filter.

I already have the K&N drop in filters and they're great.

The only thing about short intakes is that they suck in hot air which is not good, that is making me think I should keep stock or modify the stock intakes.

Good song.

Honestly though, without a tune, an intake on this motor does nothing. The intake tract is already maximized and K&N panels are going to get you the most without a tune.

I've also heard the oil-based ones like the K&N and foul up your maf/map sensor too. Doesn't sound worth it. I saw a thread, I think it was on either 6mt.net or nicoforums where someone put together a pretty comprehensive list of all intakes and their results on a dyno. I believe the r2c doesn't use oiled filters so that would be a big plus.

An Uprev guy told me that also when companies dyno intakes and post numbers, they do so with the engine running really lean(no tune) - so when you get a tune, your grains will be less because it won't be running lean anymore.

One of the reasons i bought the R2C was due to the filter quality. It has a great filter..maybe the best out there..as well as the sound

Bottom line is with a short ram you will be sucking in hot air from the engine bay which will reduce power like stated before. If you go cold air you can get the Stillen Gen3 which require some slight modifications but reduce chance of hydrolock. Or you can go with the Injens that mount in the front right and left of the bumper. The injens are tuned so you will see gains, it also makes a magnificent sound. CON to the injens is filter placement. You have to be fairly careful driving through deep puddles so they don't suck water into your engine, instantly locking it up.

I have the Injens.

r2cs all the way!

Short RAM: R2c
CAI: Stillen Gen 3 (but installation/maintenance is way more involved)

Having owned both, those are the only two good options IMO.