Has anyone ever replaced the whole rubber portion of the intake in thier TII? From the MAS to the turbo. Or has anyone ever had thiers crack? Did this cause a big vacumn leak and bad idle and caused you to run lean?

 

Actually, when I had the problem, it was because my son never bothered to tighten the clamp on the turbo intake. However, these were exactly the symptoms that I had. Also, I have read the FAQ's on many sites, and the local RX-7 mechanics have verified that cracks in the TID (Turbo Inlet Duct) are a very common problem on TII's.

Irv, Keith's dad

 

yeah. my TID was cracked bad when i first got it. crappy shudders from hose flex opening and closing the crack too.

my 87 corolla had the same problem. new inlet duct and viola

 

has anyone ever got a mandrel bent pipe and used rubber ends to connect it to the turbo? Or has anyone ever got a whole mandrel bent pipe and closed off the bov hole and the hole under it( I guess it goes to the turbo) and have a aftermarket bov vent to the atmosphere and have rubber ends clamped to the turbo and MAS?

 

My last was a 1984 Mazda Cosmo, complete with factory 12A Turbo. The airbox/AFM/TID/turbo setup was almost identical to the FC RX-7. I replaced everything except the AFM.
I replaced the TID with a Ø2.5" 45º mandrel bent steel tube about 10" long (nice swept bend) which I had flared up to 3" at the AFM end and HPC coated (just for looks), this was coupled to the turbo and AFM with rubber couplers and hose clamps (I didn't have a BOV so no connection was needed). I made a bracket (also HPC'd) to support the AFM. I replaced the airbox with the biggest K&N pod filter I could fit (3" neck), and made a cool little stainless steel square-to-round adapter to fit it to the AFM (I've got a cast HKS one on my FC). The pod filter was isolated from the engine bay with an aluminium shield and fed cold air from a 3" scoop under the bumper. The performance increase was huge (especially when you consider it cost stuff-all because I made it all myself) and it looked really trick. As soon as I get my FC's wastegate ported, this is exactly what I'm going to do, because I know how well it works. It'd cetainly work better than that TID being flogged here the other day.

 

yeah change it out with pvc or some other pipe you can feal the difference

 

But what do I do about the hole under the BOV that goes to the turbo I think?

 

If you mean the one with the little one-way valve and rubber hose, it's part of the PCV system and vents into the intake. Mine just hung there disconnected for 4 years, no probs.

 

What does it do?

 

According to the FSM it's part of the "crankcase and evaporative emission control system". Basically fuel and oil vapour from the fuel tank and crankcase are dumped into the intake to burn it off. It's just emissions ****.
And I know we don't have a crankcase but that's what Mazda call it!

 

is there any thing i could do the fix my TID crack because i need to keep the airpump on and i cant afford a fcd right now

 

So I dont need it? I can just get a whole mandrel bent tubing straight from the turbo to the MAS without any holes in it and cap off the other end of that hose?

 

That's what I did.
Unless you're going to remove the entire PCV system I'd just leave the little hose there, including the one-way valve, otherwise that system won't work.