Intake Air Box Modification

[Izzy]

This modification is for the airbox, an inexpensive alternative to the $230 ones out there. You will need the following to start:

1. Schnell air intake kit (Ebay $99 from VertexAuto)

2. PVC pipe threaded adapter (Lowes $0.89)

3. PVC threaded cap (Lowes $1.29)

The Schnell kit uses the smooth silicone orange hose, and leaves the air box muffler in. To plug the muffler, there is an orange cap and a black plug that covers the cap.

The modification will not use those, but remove the muffler altogether and use the threaded cap and adapter to seal the hole in the muffler.

Remove the air box and place on a flat surface, remove the hose and the top of the box. Turn the top upside down and remove the muffler by removing the three screws

Simply pull the muffler box out or push on the protruding pipe on top of the box

I also removed the MAF plastic screen at this stage. I leave up to you to do the same. If you want to do it, simply use needle nose pliers and pull it out.

**I replaced the stock air filter with a K&N for improved flow and cleanliness.**

Next, insert the threaded pipe fitting into the underside of the top of the box. It should be almost a perfect fit. If it is too "snug", look for non-circle parts on the fitting part that a simple utility knife can remove.

Now thread the cap onto the protruding pipe fitting threads on top of the housing. You may need pliers to make it a tight fit. Must go all the way in to seal the box.

Finally re-assemble the unit and place back in the car. Don't forget to attach the MAF connector.

The sound when you test the car will be a little bit louder, fuller if you will. The throttle response a bit quicker too. You may paint the cap black, or find it in black PVC in a plumbing store.

Have fun and save some bucks.

[SPR]

do you have the exact sizes etc. on the tow pvc pieces? thanks. The reciept if you have it would prob say the items best so someone may pick up the same without multiple trips

[Izzy]

They are standard 1 1/2 inch PVC fittings. I painted the top black, it blends in with the airbox.

[teeerex]

Hi - I've been playing with the air box myself and just read your post.

Surely it's the Schnell pipe replacement that is now making your extra intake sound - the extra resenator box sitting inside the main air box is sealed from the main unit and is essentially surpless to requirements once you've installed the Schell. I guess you can remove it (as you have suggested) but other then increasing post filtered air volume in the air box, I'm not sure what you have gained ?

Also, I've read that the pre MAF plastic lattice that you removed is used to 'straighten' the air going over the MAF ?

Just some thoughts ..

Richard.

[Izzy]

Richard,

I have since added the Fabspeed mufflers and put back in the resonator or muffler in the airbox. It was too loud withtout it. Just a sound trick if you do not have the sports muffler

As for the grill, your choice if you want to remove or not. It has been a while since I instructed Fluid Dynamics for compressible fluids in the old engineering school, but I can't imagine that grate, so close to the MAF, lowering the values or Reynolds number. Laminar flow would not give the best flow anyway, turbulent higher pressure flow would increase volumetric. I think it is just there to prevent the gerbils or other critters from getting to the MAF?

It is a pretty thick area, if you add up the small lattice, so for me removing did allow more air to the combustion chamber. Also, more sound. Vroom vrooom stuff, that is all that it meant to me.

[1982 930]

... Out of curiosity, I saw on Fabspeed's website that they advise not to remove the screen anymore, but they do not say what for... any ideas as to why they would change their minds?

Edited February 22, 2012 by 1982 930

[logray]

Whether the screen has an affect on MAF readings or not, I would leave the screen in as it would help prevent any large debris from entereing your engine. Perhaps such debris might have accidentially found their way past the filter (or if you forget to install the filter), or broken/ruptured filter/etc.

I also would be interested to know if removing the muffler has any affect on air mass flow readings. With a perfectly sealed unit, I'm guessing the muffler is going to not introduce unmetered air and rather create some sort of dampening affect with a higher or lower pressure zone the air must pass over. The fluid dynamics analysis would be interesting. Perhaps one positive might be if the muffler or hose were leaking and introducing unmetered air past the MAF.

I used to have this "cold air kit" and I did notice a little more noise.

Edited February 22, 2012 by logray

[GabbyProd]

Used this article to mod my 2002 Targa.

Thanks!

I found a black cap at Ace Hardware that perfectly matches the airbox.

I used this intake for $30 - http://www.ebay.com/itm/391414829023?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

30 minutes and it looks and sounds great. Shocking what a difference this mod makes in the sound at full throttle, with no change when you're driving mildly with your mother-in-law.