rxKaffee

I was poking around near the airbox the other day, and got the idea in my head to throw my old K&N filter on.

It looks like I could almost fit it right on the end of the AFM on the inside of the bay, but it appears to be twisted towards the front divider thing just a tad too much for it to fit. Still hooked up to its ducting, I tryied rotating the AFM a little, but it didn't move much.

I also thought about taking my hacksaw to the stock filterbox, chopping it off somewhere along the metal tubing, and securing the filter onto the end of that. Do these filterboxes have much value? I'd feel bad cuttin it up if it was worth anything.

Maybe I could just get some 3" PVC with a slight bend on one end and mockup one of those "fancy" ebay CAI setups

Any other ideas guys?

NismoPick

I bought a 280zx that the owner just took off the blue box & connected the K&N to that boot on the front of the radiator support, so it just sat straight forward.

rxKaffee

Oh, cool. I thought about that approach while I was out there looking at it but... It seemed like the boot would be too soft to get the hose clamps to hold my filter on (wouldn't want that 50$ filter bouncing out underneath the car!!) and looked like it wouldn't haveenough room front to back with the boot there. I'll definetly checkout that approach again though!

NismoPick

Maybe check out a muffler shop's extra pipes... I've gone to the local Midas several times, and asked them for a spare bend, or an extra foot of pipe. If you can find a bend that's the right diameter... just clamp it & have the filter sit in front of the radiator.

nismo619

i went to a muffler shop asked for i do beliove 3 inch diamiter with a 90* bend about 2 foot long peace of pipe bent it in 90* bend and thats what i used on my 82 280zx na. with a k&n cone filter, then withe the 280zxt it was a little more tricky i had to use the 3 inch pipe diamiter becuase of the k&n cone intake but i had to have the 3in side opened to a 4 inch diamiter to fit inisde the rubber boot end..

rxKaffee

I just test-fitted on that boot you mentioned. No go... dunno if I got a longer K&N filter than the one your P.O. used, or if the fenderbender dent up there is gettin in the way. Oh well... it didn't sit on the soft boot very securely anyway though, so I'd not have left it.

I'm trying to think of any reasons not to just chop the stock filterbox and use its hardpipe to mount on. Only thing I can think of is the turbulance that might be caused by the seams in it where they hooked the top half of the pipe to the bottom half. They are concave from the inside of the tube though, so I don't think it should do anything too bad to the air that a "real" tube wouldn't. As thin as the metal is, it doesn't look like a different solution would save much weight.

SHADY280

go to your local home depot, and for under 5 bucks you can buy a heater duct 90 deg bend, it is adjustible for diff. angles and works great, you gotta support the filter then tho, but thats not hard. i did that for 3 years of my cars life, or if you want to look fancy, go to your parts store and buy a 90 deg bend from a company called vibrance, it is chrome and looks good and costs under 30 bucks.

jfairladyz

There is no reason not to use the stock air box piping. Those things aren't exactly hard to find if you ever want to replace it. And unless you've got a brand new one chance are it wouldn't ever sell on ebay anyways. I kept my stock air box just incase anybody ever needs one. But I dont plan to make any money off of it. I say cut the box off and just fit the filter onto that. That is of course if the OD of the piping is compatible with the ID of the filter.

rxKaffee

Got the box sawed off, and it looks like the stock pipe will be a pretty good fit. Only problem I see is the joint that sticks out on both sides. Seems like it might leak air around there since the hose clamp is round and the joints are kinda uhhh... un-round.

I think if I ground 'em off just far enough back to get the clamp down good it would probably solve that problem. Shouldn't have to grind them far enough back that the thing will fall apart. Or maby I'll build up a corner filet(fiberglassing style) on each side of the joints with steel putty to get a good seal under the clamp. I'll sleep on it.

For now, its time to get all this rust off my nice new custom intake ducting! lol

lww

With the change in diameters and the odd shape of the stock box pipe, I would have just gotten some 3" and a 90 deg PVC bend from Home Depot, painted it flat black with a rattle can to cover up the markings and been done with it.

No more than $8 including the cost of the paint and you don't have to cut, modify or screw around with anything and it's stiff enough to support it's own weight and the weight of the filter without any additional supports.

rxKaffee

Well, I currently have ALOT more time (between school semesters, no job, blah blah) than I do money So a little hack-sawing is no problem. I'll be getting an rb installed at the end of the summer, and won't beable to use this intake setup for very long. So I'm trying not to sink too much money into it until then... but I'm sooooooo tempted to buy a cheap tubular exhaust manifold, lol.

Got most of the rust and all the loose paint sanded off. Decided to build up the filets with steel putty to fix the pipe joints. Gonna run it like that for a few days until I find my damn rustoleum. Its been hiding since I threatened to paint my RX-7 rustoleum brown a year or so ago.

SHADY280

the rx-7 deserves that!!

rxKaffee

Also, the OD on PVC 90deg bends are designed to recieve a standard sized PVC pipe, so they would be >3" on both ends and fail to fit in the boot at the firewall.

NismoPick

So I popped the hood on my spare turbo today... It's been a while since I've looked under thurr, I was thinkin it was a K&N filter, but it's just a FRAM. Here's the pics:

rxKaffee

Steel putty worked wonders for patching up around the joins on the pipe. Its short and light enough that I don't think I'll need any type of support for it. Been running it for a few days now, but I can only take the car out at night for a few hours... so I'll give it a few more days and make sure everything is still sitting there right and grab some plumbers tape if not.

NismoPick

Now that's quality!

jfairladyz

you can pick up aluminum piping on ebay for next to nothing. And its cheap to ship (cause it's aluminum )

Heat Rave R

I just bought a piece of 3" 45-degree angle Spectre intake tubing for $10 (available at Pepboys, Kragen, Napa, etc) and it fit just right. My filter had a hole in the end through which to put a bolt, so I could have the end supported, which, because of the 45-degree angle, pointed it right at the old filter box bolt hole.

mikeyman

and to buy a cheap K&N. Simple just buy a fram that happens to have a K&N in the Box

datsunl28et

good call I just used a 3" intake pipe from a prelude AEM CAI which was the second piece that dumps down the fender in front of the bumper. On my car it just puts the filter in the middle in front of the radiator

RodMoyes

Exhaust shop...

Already bent piece of 3" pipe... Zero Dollars

One rattle can of red spray paint... Five Dollars

Non-resuable cone filter... Nineteen Dollars

Looking like you spent a bunch of money on a prefab CAI... Priceless.

datsunl28et

Nope the only thing I bought was a filter from discount that I bought like three years ago and it has been used on several of my cars and I did not buy the aem intake piece, got it of my friends wrecked prelude so.... 20 bucks anyone thats all I paid for a filter that has lasted for three years and a polished intake pipe for free, good investment i think!!!!!