Originally Posted by Huck

There's a lot of debate about it. Here's what I've been able to gather after lots of thread lurking...

Some people just like to do the drop in filters from K&N with the stock air boxes, or to add the Z1 post MAF silicone tubes. That all comes up to about $200, and is a pretty good setup. The thick silicone tubes keep the cold air colder, insulating it from the engine bay temps. And the drop in filters flow pretty well. The downside is that the filters let a bit more dirt into the engine, and the stock boxes are still in the engine bay, so your not getting the absolute coldest air possible. All in all, for $200 it is a very good setup.

I have not seen any dynos for this setup, so I don't know for sure about what kind of gains you will be getting with this setup, but I would venture a guess of around 10ish hp.

However, if you're anything like me, you want the best. I would be unhappy to have a cai that made 14hp, and I find out there's one that makes 20hp, that's gonna stick in the back of my mind. Every time I see someone with the nicer one I'm gonna be totally jelly. So I did my research and finally settled on the Stillen Gen 3's.

The good points are that it's a long tube design that sucks up nothing but the coldest air from inside the front bumper. There's also a DIY thread floating around here on how to duct more air too the filters for another 2ish hp very cheaply and easily. They have proven dyno gains of 17.5 hp, and I can definitely tell a difference in the butt dyno. It also gives a great new growl sound at WOT. And it's made by Stillen, which has been synonymous with Z cars for a long time now.
The only downsides I can think of are:
1. Installation is a bit more complicated than the others with some cutting involved.
2. About every 15,000 miles you have to takeoff your front bumper to clean the filters
3. They are the most expensive of the cai's at a little over $500 new. That being said, you can find used ones here from other users for around $300 to $400 all day long.

So the bottom line is, yes cai's make good gains, it all just comes down to how much you are willing to spend. Some people don't want the absolute best, the just want something nice. There are plenty of options out there for you, and the drop ins with maf tubes are good. But in my opinion, and the opinion of a lot of other users on this forum, the Stillen G3's are the best.

Sent from my iPizzle using magic and new fangled science stuff.