Ok loud intake haters,
Here's how the box is made.
What u need!
Tools:scissors, hole saw, hack saw or pipe cutter
1. Shampoo bottle cleaned out well at least 3in Diameter. Less diameter doesn't work as well idk why
3. Few hose clamps
4. A foot of 3/4in irrigation tubing
***5. Some rigid wall metal tubing or pipe, size depends on your hoses
So what ya gotta do?
Select hoses. The combo hose setup I use here is specifically for phbg, cuz the sump pump flex hose hits it perfect. Otherwise you could just use a radiator hose that fits your carb. In this situation, I'm using a 1.5in ID 2in OD radiator hose to join to the bottle. The flex hose is about 1.25in OD when stretched.
1. First cut the bottle all the way around so the top can slip over the bottom section. You'll have to cut a notch in the bottom section to allow it to shrink when the top part goes over it in a slipfit. Clean it again.
2. Next, get your hole saw and pick a size of hole that is smaller than the OD of your radiator hose. My hole is 1.75in and the hose is 2in OD. When you squeeze the hose into the hole it will be mostly airtight due to the interference fit.
3. Then! ******
Find a piece of pipe that just fits into the larger radiator pipe, that will be inside the airbox with stretched pantyhose around it, and hose clamped or cable tied to the sandwiched pipe~>hose~>pantyhose~>clamp
Doesn't matter what metal you use, pvc might work too but I never tried it.
4. Squeeze the filter/hose assembly into the bottom of the airbox from inside. Spit and pliers helps, sounds like a hot date!
5. If you're phbg'in it, find that flex hose and cut a length that'll work for ya, I go as short as possible, but up to about a foot. Find another metal tubing spacer that fits tightly inside the flexy tube. Then screw the flexy guy with the metal tubing in it up into the radiator hose on the bottom of the airbox. Once it's in, hose lamp it into position on the outer radiator hose.
6. Now cut your intake ports in the top section. I usually cut a very small circle in the bottle then cut an X to about 3/4in. The tubing will slip in easily and stick in due to interference fit.
7. Cut the intake tubes from 3/4in plastic irrigation tubing. I do length anywhere from 1/2in to 2.75in.
You can have anywhere from 2-4 tubes, you can experiment with tubes of different lengths, plugging some holes with rubber cork, some long tubes, some short. The more tubes the more air, but also more loudness.
I cut a X into the outer end, and use pliers to bend them out into a flange, so they don't fall into the box. You might have to jet down a touch with this mod if you're at 4 short tubes and it's still too rich.
But then it's very easy to change your jetting as you can pull a tube entirely out of you need more air.
It's all experimentation.
8. Assemble the top and bottom sections, and wrap tape around to seal. Electrical tape works great for this.
That's pretty much it. Changing airflow for your jetting is so easy once you have a setup dialed in.
Feeling a lil lean? Add a longer tube or add a cork to one of the ports.
Feeling rich boggy? Add some shorter tubes or pull them all out.
No intake tubes will still silence the intake, but not that well. The tubes are the key to this setup.
The dome top really does a lot of silencing due to its reflection of soundeaves back into the intake.
1.don't leave much extra pantyhose on the edges as it can flip up into the box when you're running and block air.
2. Make sure that pantyhose is streched tight and clamped hard. If it comes off it's got a one way ticket into your carb and engine.
3. As for the top of the bottle, if you decide to make that a port as well, it allows like 3x the air as the side ports. It can make you run lean, I usually just keep the cap on these days.
Ok that's it. It's super simple but I don't think I ever made such an in depth instruction guide.
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