I received the Stillen airbox in the mail a few weeks ago. Got it for around $200, which seems to be the standard. When I opened it up, the K&N filter looked very top quality, but the box itself seemed kind of cheap. I was worried.

And then I read all the posts from people with install troubles, especially with that M6 bolt.

So when I finally got around to doing the install, I opted to just leave the M6 bolt out of the equation. I did everything else that the directions recommended doing, just left the M6 bolt off. Some other people did the same thing, and they said it worked fine, and so far it's been 100% fine with me as well.

Without that bolt to worry about, the install took me about 35 minutes. For you do-it-yourselfers out there, the most complicated thing I've installed on a car up to this point is the Crawford plenum. So if you hash through Stillen's horrible direction sheet, you'll be okay.

Prior to this mod I had a Crawford V5 plenum and a z-tube on an otherwise stock 6MT coupe.

When I started the car with the hood up, there was no sound difference at idle unless I got REALLY close to the airbox and listened to the slight extra intake hissing. Then I got in the car and revved it a few times, and there was the standard intake suck after a sharp press on the gas pedal. It sounded just like any other intake I've heard, which was actually a good sign because I've had good experiences with installing intakes on previous cars.

Then I took my first test drive (windows down). In normal, non-spirited driving, there is very little if ANY difference in sound between the stock airbox and the Stillen airbox. When I floored it in a higher gear (say... 4th gear @ 30 MPH), I could tell that something different... something a little deeper... was under the hood. But it wasn't a huge difference - probably not noticable to anybody who doesn't REALLY listen to the sounds their car makes.

But then I floored it to redline through a few gears. I was absolutely shocked at the difference this airbox made. In the upper half of the RPM range (say... 3500-6500), this thing is SO LOUD. My VERY FIRST thought was that the cabin of the car seemed to be FLOODED with sound when I was really pushing hard. It was pretty much only when I floored the car in the upper half of the RPM range, but the difference was HUGE. I absolutely love it - it takes the mechanical-sounding, relatively quiet engine noise and turnes it into a deep, wailing that seems to come from everywhere.

I didn't take sound clips to compare before vs. after thinking that the difference wouldn't be this huge, but I should have.

Also, after I installed the Crawford plenum on my stock car, there was a difference in PERFORMANCE but not TOO much difference in sound. It got a little deeper and had a little more aggression. But the Stillen airbox, on the other hand, really enhanced the sound a lot.

You can still hear mainly the exhaust at low RPMs. The exhaust still has that burble at 1500 RPMS and still has that nice wailing at 3300 RPMs in normal driving, but once you get on it, the combination of the Stillen airbox and the stock exhaust blend perfectly to give the impression that the sound is screaming at you from everywhere.

To me, the sound alone is worth the $200, even if there is little-to-no performance gains. It TRULY made a huge difference in the sound. The car sounds awesome.

Let me know if you have any questions. -Phil

 

Phil,

Glad to read that your Stillen HFAB install went smoothly. Hehehe . . . Have you stomped on it in the lower 3 gears at 3.5k to 4k? Enjoy!

Edit: Are you running the Stillen HFAB with an OEM intake tube or with a Z tube?

 

Looking forward to installing the Stillen high flow airbox myself today. Hope I can have the same results.

 

Yeah I've definitely stomped on it to redline through all the first 3 gears. It really is amazing to me how loud it gets when it's floored.

And yes, I'm running it with a z-tube as well as a Crawford V5 upper plenum. Only other mods I've got.

 

When I take mine off to clean it, I replace it with the stock air box for a couple of days to let the oil clear off the cone filter. Oh how I miss the Stillen HiFlow when it is off. Can't hardly wait to but it back on. AND.. I never noticed a gain in HP or torque when the stock airbox is back on. It is a myth that the Stillen HiFlow causes a loss of torque. I just love it!

 

I sure like my Stillen CAI and 350Z air tube. I also noticed an increase in power with no loss of low end torque.

 

Cato,

Thank you for the excellent idea.

 

aside from the air filter, I still don't see any difference between the stillen and the stock intake, what's making that loud sound? the cone air filter? does the JWT sound just as loud as the stillen?

 

1. Just replacing with the Z-tube gives more sound (no resonators as with the G's OEM).
2. Yes...IMO...but curious what the stock air box w/ K&N and Ztube sounds like. Many ppl do that set-up.
3. Yes, but haven't heard the Stillen for comparision.
My JWT added a nice growl under the hood that added to and compliments the nice tone of the stock exhaust.
But now with my Injen dual track edition exhaust, that's all I hear now.

 

Just installed my Stillen Box and Z tube. Could not ask for a more perfect sound combination. I have a spacer ready to be installed, but I was just wondering what kind of affect this will have on sound and power.

 

i think there is something about having both the stillen and the ztube. i had the stillen box on without much difference, but the combination of both box and tube resulted in a deep and loud wot noise.

 

yeh..you wont get any noise unless you have a ztube...............

the gtube is "baffled" which makes it quieter..so the stillen air box with gtube is kinda pointless...

 

actually, my point or question is whether you get the same sound with just the tube and no stillen? sounds like this guy had a ztube and no stillen, and the the car was not loud until he put the box on. my situation was the opposite. i had a stillen and didn't get an increase in noise until i put the tube on.

 

Hey everyone. Just to avoid confusion, I actually installed the z-tube and Stillen intake simultaneously. So I can't comment on which component truly made the majority of the sound difference. However, from past experiences with installing short-arm cone-style intakes in other cars, the cone itself made a huge difference in sound. Because of that, I assumed that the sound difference I heard was primarily due to Stillen's airbox.

 

God damn, a simple intake install and excellent review. Props for do-it-yourself and taking the time to write a review. This is what I like to see, satisfied drivers!