BASELINE

Guys,

I haven't had the time to crack open my GF's intake for measurements. Does anyone know the diameter of the Inlet hole on the bottom of the stock Airbox? From what I understand, its not perfectly round, so a Length x Width number would be awesome, but i'll take what I can get.

Also whats the diameter of the intake tube between the box and the resonator??

This info would be greatly appreciated....I'm hoping some of you guys with installed CAIs can measure this for me as its out of the car and easily accesible.

Another thing that puzzled me was when feeling the rubber accordian hose that goes from the Throttle body to the Airbox, there is a "hump" on the underside of that hose on the throttle body end....why is that? I can't think of why that would be there.

Thanks again

BASELINE

Common...33 views and NO ONE knows this?!

BASELINE

66 views and counting!! Guess i'll have to figure this one out alone.

BASELINE

66 views and counting!! Guess i'll have to figure this one out alone.

CAHobbs

Hey BASELINE,

Excuse me if I don't get this right the first time around (brain isn’t what it used to be) but here goes...

The opening at the bottom of the air box is oval and measures approximately 4" x 3 1/2". The tube attached to the top of the resonator appears to be glued on. The opening on the bottom of the resonator is round and 3 1/2" in diameter. The air goes into the driver's lower grill on the outer side and is then forced up into a short curved tube into an open chamber where the air swirls around for water separation and then it flows up and into the tube leading to the resonator.

I believe the “hump” you’re talking about is below the vapor recovery tube at goes back to the rear valve cover on the engine and I think it’s just a design to add extra support in this area and possibly aid in keeping any oil in suspension.

I tried to attach a picture of the intake but I guess I haven't figured that part out so I am PM'ing you with the picture.

Hope this helps!

I tried

Happy Motoring!

CAHobbs

If you need more info, look at this thread

https://acurazine.com/forums/showthread.php?t=145602

and try contacting aznbo187

Included are pics of the intake.

Happy Motoring!

aznbo187

iTrader: (1)

What are you trying to do? If you are getting a CAI, you will not be utilizing your stock air box anymore.

BASELINE

aznbo187,

Hey bud! Not installing a CAI, its the GF's car and I don't quite trust her with a straw hangin out the front of her car. So I figured I'd have some fun with it, and really engineer something myself, I've done it before on other cars...some street and some track...but usually with great results. Not to mention it would probably be a bit quieter than the Long Tube CAI's and potentially offer better tip in throttle response.

CAHobbs,

Thank you, SIR! I was starting to worry that there was a lack of technical "know-how" in this forum but you have proved me wrong. Your brain is working just fine!! I appreciate the concise info....I think you're right on the HUMP being "extra support" for the vapor recovery tube.

I'm a bit surprised on the actual size of the airbox inlet size, it's actually pretty big and should not represent a restriction, although I'd probably open it up just a hair to make it round. So, if there are gains to be had from decreasing pressure loss in the intake system pre-TB, a lot of it will likely come from the replacement of the whole resonator/pre-airbox system with smooth internal plumbing to a fresh air pick-up location. Maybe add an air directing piece from the bumper towards the new pipe opening....although without attaching the two. I think leaving a few inches between them would mitigate water ingestion; not to mention...I am not so sure that corner of the bumper is a high pressure area at speed, so doing it this way will also ensure the engine is getting the air it needs at all times with minimal loss to throttle response.

I obviously haven't looked inside the airbox yet, but I'm sure i'll find a few areas and transitions that can be smoothed out and/or trimmed to improve the overall volumetric efficiency. An aftermarket filter would be nice....but I can't seem to find any company that makes either a multi-layered foam unit or cotton-guaze as they changed the design for '07. I don't know if trimming the filter of the 06 to fit in the box would be worth it....i have considered making a Cone fit INSIDE the box if I can get one with the right dimensions with an off center angled inlet. Either way....in the testing i've done on other cars i've worked on, the filter usually represents a very small restriction when comparing NEW vs. NEW....but it would be nice to know you're getting as much flow as possible.

The diameter of the Airbox "EXIT" seems to be of a healthy diameter as well, so I would see no need in modifying it unless necessary in the event i went with an "internal" cone filter of sorts. However the accordian flex rubber tube that goes to the TB is gonna have to go....ribbed hoses create flow havoc and sometimes are only as flow efficient as smooth pipes 20-30% smaller in diameter. Granted its a short section, but why go through all the hard work in decreasing intake pressure drop and creating laminar flow to have it do a circus tumble into the throttle body. In the end, its the sum of many well thought out changes that make a system work well. I'll have to use a short pipe with two silicone hoses on each end short enough to not allow any "collapsing" yet long enough to allow for some flexibility from engine movement.

I plan on doing before and after dyno's of this little homebrewed intake design, take some pics etc. Who knows....there might be some interest for others. Maybe i'll do some modifications to the mid-pipe portion of the exhaust (mid-muff/resonator) at the same time.....see how much DIY hp there is to be unlocked in a TL-S 6sp.

Should be fun....even if it proves to be an exercise and the gains are minimal, but i'd be surprised.

aznbo187

iTrader: (1)

I'm actually going to go back to my modified stock airbox setup as well. Had several "cone" filter, tube style intakes, and don't really like the sound of them, nor the decrease in certain rpms.

Keep me updated on your progress. GL!

CAHobbs

Hey BASELINE,

Glad I could help and I want to thank you and aznbo187 and all the other homegrown modders out there!

You're the guys that lead the way for the rest of us and show what can be accomplished with some sweat, a lot of imagination and a ton of determination!

Mod on and Happy Motoring!!!

P.S. When you’re done, share some pictures, OK?

BASELINE

I'll be sharing pictures, parts list, price and before and after dynos....i don't fk around.

Stay tchoooned!!

CAHobbs

Awesome BASELINE, that's what we like to hear!

aznbo187

iTrader: (1)

Seems like it's just us 3 lone rangers that care for the good ol' tuned airbox performance!

BASELINE

Hopefully we'll change everyone's perspective. If this works well, I wouldn't mind selling it as a kit...who knows!? I think the reason its not that popular is because most would rather just "bolt" something up. And they feel buying an intake from a big name company is the only way to go, while they don't feel like messing around with modifying parts...or just wouldn't know what to do.

We'll see what happenes.