I just took off my stock air box, and put on an aftermarket cold air intake, but what is the hose for under the stock airbox? can I just leave it open, what does it go to, and should I plug it? thanks guys!

 

I Cant Remeber If I Had One Or Not I Would Cap It Off And See How She Runs If Good Leave It If Not Leave It The Way It Is

 

I just ran the car in the driveway, didn't go anywhere yet, and plugged that line with my hand. it didn't sound like it made any difference, but It was sucking air into somewhere. looks like it goes either to the bottom of the engine or the trans. I have a 1980 280zx with auto. trans.

 

It goes to the bottom of the engine. The '79 and '80 ZX had those hoses but the '81-'83 ZX did not have them. The hose connects to a small black box thing and then connects to the bottom of the intake manifold or maybe it connects the the PCV, I can't remember. Anyway, try tracing it and blocking it at the source and then get rid of that stupid hose.

 

so it does nothing for performance, gas mileage, cooling,...It's gone first thing tommarow morning! I did go out and test it with that hose just kinda danglin, and at low rpm, there wasn't a big change, but between 2500 and 4000 rpm, it was night and day!

 

It would probably be a good idea to put a breather on where ever the hose connected to the engine.

 

Like a mini cold air intake? It's either inch and quarter or inch and half hose, where could I get one or how can I make one?

 

I know Pep Boys and / or AutoZone have small breathers like that ... and they're relatively cheap.

If you want to ghetto it up [probably not reccomended], I would suggest getting some cotton filter material or something and wrapping it around the end of the hose. Be sure to clamp it on so it won't fall off and get ish in the hose.

 

for a temporary fix I put some cheese cloth, AKA cotton mesh that doesn't have fibers that fall off, around the end and used the existing hose clamp around it. I'll check pep boys this weekend. thanks guys!