So a couple weeks before I parked my car last year I installed the HKS intake for the stock twins. It worked fine for those weeks and I had no problems. I just took my car out of storage today and gave it a thorough tune up. One thing I noticed that I'm a little puzzled/worried about. As I was checking all the hoses I noticed that one of the hoses connects to the engine but isn't connected to anything at the other end!? The middle part of this hose I replaced as part of the intake kit, but the ends are stock and I haven't touched them.

I included pictures with the hose in question circled. One with the way it looks normally, and then one with the hose pulled out. Is this normal or should this be connected to something? I looked for about 15 minutes trying to find what this hose could possibly connect to but couldn't find anything.

I feel dumb for asking this but I don't see where it would connect to, and I don't see why they'd have a hose that doesn't go anywhere.....

 

Looks like it's connected to the charge control valve/elbow. It vents excess boost from the secondary during prespool, IIRC. Shouldn't be a problem unless your CC valve malfunctions or sticks open, in which case it'll just become a massive boost leak.

 

i believe that goes to your cat, there should be somewhere on the airbox for it to connect to, thats connected to the airpump.

 

You should either connect it to one of the HKS pipe or replace everything from the black HKS cylinder by a little airfilter, that you would fill with foam in order to minimize the mooo sound.
You can leave the bov vented if you need to free a connection in the pipe.

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/eliminate-air-pump-moo-%241-1-minute-486061/

 

oh man...this is what i love about rx7 club. simple question = multiple wrong answers. haha

 

Ok, there's a little confusion I guess on which hose it is, my fault. Not good pictures. So here's a new picture showing exactly where it connects. I looked again and I still can't find anywhere that this hose could possibly connect to. I don't think I've ever had my car "moo" lol, so I don't think it's that.

 

It's the same thing. If you car is the one pictured in the first shots in this thread, there is a silencer in that line which suppresses the "mooo". However, it looks like crap to have a hose going no where laying in your engine bay so most people want to remove it. Removing it (meaning removing the silencer) creates the "mooo" sound people talk about.

 

Ok, cool. Thanks. I'll just remove it then. Just curious though, what is that hose actually for?

 

If you intend to keep your air pump functional you need to keep this hose--it discharges excess air from the air pump.

 

Use the link I posted up above on how to mute the "moo" sound.

 

unless you are going to remove your air pump, don't remove that hose/silencer.

 

Alright, thanks a lot guys. I read that link Mahjik, but unfortunately the link that was posted in your link was dead. I still know what they they're talking about, so thanks again.

 

No problem, just look at the picture I posted in there of my engine bay from a few years back. It will give you the jist of what needs to be done. IMO, it cleans up the engine bay better than having a dangling hose laying around.