Just installed my stillen airbox and z-tube. The sound above 3000 rpm's is unbelieveable, gave me goosebumps. You can't tell a difference below 3000 rpm. I also noticed that to really get the full effect you have to be on it pretty good. Power wise I couldn't tell if it makes a difference, somedays my car pulls harder than other days, it felt strong tonight, but it could all be in my head.
The negatives are that the installation is fairly easy except for attaching the bolt that goes on the AC line on the frame. Pain in the ***, took me hour and a half to secure. Which will probably have to be taken out when you clean the filter, not looking forward to that. I'm not really impressed with the quality of the stillen box, anyway it fit just like stock.
The Z-tube was the easiest thing I ever put on a car. That part took maybe 10 minutes to take apart and put back, If I was doing this all over I probably would not buy the Stillen Airbox, just Z-tube and k&n filter. But i'm not sure if that combo would sound as good as the stillen box plus z-tube.
Just ordered the Grounding Gear 10 wire kit from Gordon, i'll let you know how that goes when I receive it.

i keep hearing how its a b*tch to install that one bolt for the Stillen....what if you didnt use that bolt and just left it?

I started out with the Z-tube. Then added the K&N panel filter. The K&N panel filter adds NO sound whatsoever. When I added the Stillen HiFlow AirBox.....Wowa!!!! This combination is awesome. Then I added the HKS muffler......Wowa!!!! I could feel an extra "grunt" on hard acceleration with the HKS... So..your Stillen + Z-tube is the way to go.

It's fine without it... there is a mounting bolt on top that secures it just fine.

thanks for letting me know.....

so is the Stillen louder than the JWT popcharger?

And is the Stillen better since it has its own enclosed box rather than JWT's partial heatshield?

remember reading a thread where some guy didnt screw one of the bolts and the CAB ultimately had a crack and he couldnt get a new one for it. not sure if its the same bolt tho....

I have had the Stillen HiFlow AirBox for two years now...I never used the bottom bolt as it is next to impossible to install. Cleaning the Stillen is pretty easy by not having to deal with that non-essential bolt.

I don't know why they designed it that way. It was pure luck that I was able to get that bolt started, after an hour and a half I finally got it. I was about to give up on it because it did see secure without it. When I clean my filter I will probably not resecure it.

Anyone who actually got that bottom bolt in will regret it when cleaning time comes. hehe..... I have had mine off twice now for cleaning. I't not too difficult to clean..It does get pretty dirty..

I've had my Stillen CAI enclosure on and off over a dozen times and always install the bottom bolt. To reach the bolt I remove the power duct and use a long 3/8" extension, a universal joint and 10mm standard socket. It's usually a staight forward deal... but not always.

Wow DaveO! How do you get past the cone filter? I still don't see a reason for this rediculous bolt....

Cato,

The way I do it leaves room to slide the extension down in front of the air filter. It's easier if the inlet tube's not connected to the Mass Air Flow Sensor and of course you'll leave the upper enclosure bolt for last.

As for it's purpose, I suspose it's because the enclosure is flexible and this bolt adds some rigidity. That said, I'd be willing to bet that they're more Stillen CAIs installed without the bottom bolt than with it.

It only take a extra 15min to install th bottom bolt. Isn't your car worth it????

That's how I installed mine with the extension, 15 minutes though I don't believe even with the extension. you can't see the hole through stillen cover it's not that easy top line up. With that said drove my car to work this morning and the sound getting on the highway was unreal. I was planning on buying an exhaust system, but this sound takes care of what I wanted.

Yeah but... no one, I mean NO ONE is as thorough as you Dave! You know I'm not as patient - I'm bringing the car to you when I clean air filter next time!