240sx Homemade Cold Air Intake writeup

by thenameismatt.

Overview:

Create your own custom intake system to relocate the filter outside of the hot engine bay.

Warning: This looks really long because I wrote out everything in detail for you guys, its really not that bad.

This method allows you to continue to use the AIV if you do not wish to disconnect it.

Difficulty: ***

Time: 2-4 hours

Cost: $30-$50

Tools:
– Grinder
– Drill
– 3/8″ metal drill bit
– A couple screwdrivers
– Channel locks

Materials:
– eBay RAM intake kit
– JB Weld (1 oz tubes)
– Electrical Tape
– 1/2” cone filter
– Small pieces of cardboard
– 15-20 feet of 4-AWG wire
– Four 4-AWG wire connectors

Procedure:

Disconnect battery and remove from engine bay

Remove stock airbox and intake runner, leave all the vacuum hoses connected in the engine bay.Also leave the rubber boot nearest the throttle body.

Grind out a hole in the battery tray large enough for the cone filter to fit down into.If you do not want to cut into the firewall, just factor in that you will have a much shorter intake tube and some of my measurements may not work for you.

^Yes that is being held on by electric tape… I lost some of the ring clamps and had to use that for the picture (its fixed now)

Grab your eBay intake tube and the grinder.MAKE SURE YOU WEAR SAFETY GLASSES!!!I got a metal shard in my eye at work a week or so ago and it sucked big time.Ok back to the tube… See how there’s three bungs on the tube?One big, one small, one big.Grind off the two big ones as close to the top of the weld as possible (goal here is to save the two bungs in as close to perfect cylinder-shape as possible).Save those bungs… you will need them.

Cut off the filter end of the tube as I have measured out in the picture with the grinder.

Grab the drill and your 3/8″ bit and drill a hole as I have measured out in the picture.

Now this is gonna be tricky… mark this line across one of the bungs and then try to grind it along that line so you have an angled bung. Use the channel locks to hold the piece while you grind it.

This is the bung that will be attached where you drilled the 3/8″ hole on the tube.Save the second bung you still need it!

Now it’s welding time!!Haha I know mine look like crap but oh well it does the job.Anyway, take a piece of cardboard and wrap tape all the way around it, then lay a longer strip on one side, this will be used as a stopper to keep the JB Weld from seeping through into the intake.Tape it in over the hole, I could only reach the first one good luck with the second.Mix up the JB weld and begin patching the holes… leave the small bung open its gonna get used I promise.Now ‘weld’ on the bung to the hole, angling it as I have in the picture.Once you get everything how you want it tape them all up so the weld doesn’t seep through or bubble out while its still wet and to hold the bung in place.Let it dry for a few hours then come back and weld the second bung onto the first one to lengthen the bung to attach the hose.I didn’t take the time to do this as it wasn’t completely necessary, the hose attaches fine with just one bung.

after weld is dried enough:

Take your wonderful new intake tube (with the MAF properly attached and the hole that was for the AIV hose stopped up) and wiggle it down under the radiator hose and up into the rubber boot at the throttle body.Now look under and notice the really small vacuum line is almost right at the small bung… I told you it was gonna be used! Attach that hose to the bung (you may want to cut the hose down a bit).

Now attach the mini breather filter thing onto the AIV:

Attach the larger hose to the bung you welded on, then tighten up the hoses and intake tube with the ring clamps.

Move the battery over to the other side where the airbox used to be (a smaller battery would be A+ material or relocation to the trunk even better) and connect all the wires up using the wire connectors.I relocated the battery to the trunk so it’s not in the pictures.The extra wire you see hanging out is the negative wire I was going to use to put the battery on the other side I just haven’t taken it out yet.

Results:

Quicker throttle response, sounds a lot meaner and deeper!The idle goes up a little bit but just adjust it using the idle screw adjuster.It took me about 2-3 hours of working time obviously not counting the drying time for the JB Weld.And a lot cleaner looking engine bay.

NOW GO OUT AND DRIVE ON!!!!!!!!!!!!